How to configure OpenDKIM on Linux with Postfix and setup bind zonefile

This guide assumes you have a working Postfix server and want it to sign with DKIM. There are a few things we have to understand to make all of this work though, which require you to be familiar with DNS as well. 1.) Install OpenDKIM apt install opendkim systemctl enable opendkim 2.) Edit /etc/opendkim.conf Syslog yes SyslogSuccess yes Mode&nbs........

efibootmgr: option requires an argument -- 'd' efibootmgr version 15 grub-install.real: error: efibootmgr failed to register the boot entry: Operation not permitted.

This sometimes happens when trying to install the EFIversion of grub to a device when you are booted into Legacy/MBR mode. It doesn't seem to occur on all machines, but some and seems somewhat BIOS dependent. grub-install --target=x86_64-efi /dev/sda Installing for x86_64-efi platform. grub-install.real: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image.. grub-install.real: warning: Couldn't find physica........

[error] (28)No space left on device: Cannot create SSLMutex Apache Solution Linux CentOS Ubuntu Debian Mint

Have you got this error from Apache? [notice] suEXEC mechanism enabled (wrapper: /usr/sbin/suexec) [error] (28)No space left on device: Cannot create SSLMutex At first glance it appears that you may be out of disk space but the issue is ipc or interprocess communication. This will clear out the ipcs processes so things can work, this often happens during high traffic and may be a sign of DDOS. The command below will fix it, it will list al........

How To Setup Python3 in Ubuntu Docker Image for AI Deep Learning

The issue is that Docker images are stripped down, so many tools and even python3 is missing, so you'll have to build or update the actual image yourself. I assume you have started an image with something like this and that you have the Nvidia Toolkit installed (assuming you are using GPUs). If you're not using nvidia just remove --runtime=nvidia --gpus all. docker run -it --runtime=nvidia --gpus all ubuntu bash These works for most images li........

How To Enable Linux Swapfile Instead of Partition Ubuntu Mint Debian Centos

This may be necessary if you have a VM or if for some reason you just want to be more efficient with your space and have the flexibility of changing your swap space at will. What we mean is the ability to use a "swap file" or similar to the Windows "pagefile" that normally resides on the root or c: partition of Windows. Here's all you have to do and then you to can have a single partiton with everything, including the swap file on the root partition if you........

How To Create OpenVPN Server for Secure Remote Corporate Access in Linux Debian/Mint/Ubuntu with client public key authentication

Why choose OpenVPN instead of a firewall appliance? OpenVPN can be a reliable and easy replacement for traditional hardware or just be an additional tool that your company uses so that the firewall can focus on its job rather than acting as a VPNappliance at the same time. When comparing OpenVPN with traditional firewal........

How to allow SSH root user access in Linux/Debian/Mint/RHEL/Ubuntu/CentOS

A lot of newer installs will automatically prohibit the root user from logging in directly, for security reasons or they will only allow key based access. If you know what you are doing/don't care about security or have an incredibly secure password for testing, then you can enable it. Edit this file: /etc/ssh/sshd_config Find the following line: PermitRootLogin Set it like this: PermitRootLogin yes Now rest........

How to install Kubernetes with microk8s and deploy apps on Debian/Mint/Ubuntu Linux

Kubernetes Easy Beginners Tutorial/Architecture Guide Kubernetes is known as container orchestration and we should start at explaining the container part of it. A Container is what runs the actual application and based on an Image, and are more comparable to something like an LXC Container, Virtuozzo/OpenVZ using the Linux Kernel Namespaces feature. Containers run these images as independent, isolated operating environments under the O........

?? Question Marks for time, permissions and size of a file?

-?????????? ? ? ? ? ? shadow ----------. 1 root root 748 Jul 10 04:35 shadow- cat: shadow: Input/output error If you see this you are probably in big trouble, it could be a physical error or if it's a VM image that it is corrupted due to a physical error on the underlying disk/array/NAS or it could a........

CentOS 6 impossible to compile a newer libguestfs

yum -y install gcc make gperf genisoimage flex bison ncurses ncurses-devel pcre-devel augeas-devel augeas readline-devel checking for cpio... cpio checking for gperf... no configure: error: gperf must be installed configure: error: Package requirements (augeas >= 1.2.0) were not met: Requested 'augeas >= 1.2.0' but version of augeas is 1.0.0 yum remove augeas augeas-libs augeas-devel wget http://downl........

AH01630: client denied by server configuration:

This happens when upgrading to Apache 2.4 from 2.2 or just because you don't have the right permissions set which we'll get into. You need this in the ........

apache symlinks denied even with followsymlinks

Symbolic link not allowed or link target not accessible: /path/httpdocs/news.html There are a few reasons that can cause this message and this is for people who have ruled out the basics, eg. your symlinks are enabled and the right permissions are applied (but read on to learn about ownership requirements above the directory in question). So there are a few key things here that cause Apache not to follow symlinks:........

how to use ifplugd in Linux to execute a command or script when a NIC cable is unplugged or plugged in

It is fairly simple to use once you know how to use it. However, the tricky thing is that by default it doesn't seem to be active or listen on any interface on manually specified. How To Install ifplugd First we install ifplugd sudo apt install ifplugd Let's enable it on our desired device(s) vi /etc/default/ifplugd set this line as so:........

Wordpress overwrites and wipes out custom htaccess rules and changes soluton

cat .htaccess RewriteEngine On RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . index.php [L] I keep reading there is a "# BEGIN WordPress" and a "# END WordPress" in the wordpress htaccess above but there is clearly not. Even more strange is that my permissions are just 444 (read only). so i changed it........

Using Microsoft's Group Policy Management Editor (GPME) To Change Default Permissions and Internet Explorer Security Settings

The defaults in Windows 2016 server leave clients crippled so they can't even download basic files or software. But Group Policy Management Editor comes to our rescue! Use cmd or Powershell and run: gpme.msc Choose your domain/computer and then navigate like below and create a new menu entry for IE11 or whatever your version is. Don't be worried if the highest version is IE10 it means that it applies to IE10 AND above.........

Debian 9 SSH root password authentication failure password not working problem / solution

In Debian a lot of times SSH disables the root user to login by password by default. This means you will get an authentication failure as if you typed in the wrong password. The logs also indicate the password is wrong but what is often the case is in the config file Check /etc/ssh/sshd_config cat /etc/ssh/sshd_config|grep -i permitrootlogin Make sure it says: PermitRootLogin yes If not change it and restart SSH........

Linux What is umask (user mask) for file and directory creation permissions and how to calculate umask and change the defaults

umask are the default permissions that are applied when a file or directory are created. To see this in action simply just "touch filename" or "mkdir somedir" and you'll see what default permissions are applied. The first thing Ialways tell people you should know is to NEVER change the defaults unless you are making them more restrictive. But they work well and if you change the defaults you could end up creating a file without permission to read........

Linux Permissions and Groups Real Usecase for Group Access

Ihave a directory structure which the primary user needs full access on but wanted a user to access only a specific directory within the main directory (so they could write in there only and nowhere else). Here's what Idid: [root@compevo8001 dllnow]# ls -alh drwxrwxr-x 2 someuser software 4.0K Oct 19 2017 ExpireYMD-2017-11-20 drwxrwxr-x 2 someuser software 4.0K Nov 19 2017 ExpireYMD-20........

gvfs mount in /run/user cannot be accessed or displayed wrong permissions Error: Location is already mounted

You get errors like below and see you have all question marks for the permissions if you go to /run/user/1000/gvfs If you try to access the mounted share such as anything mounted as gvfs like an SSH share in your file manager you may get an error like this. It generally means an interruption in communication or a fault with gvfsd has caused it. Solutio........

Supermicro IPMI / KVM / BMC Remote Console Screen Resizing Issue - Window Cut Off Solution

It could just be my specific Java but other KVM/IP works ok on my machine but with Supermicro's IPMI for some reason the console window doesn't resize and even putting it in full screen leaves the window cut off as shown below: As you can see above the screen is cut off you can't see the "Iagree" on the right side. The window resi........

VSphere InternalServerError - Error When Adding Permissions

InternalServerError (com.vmware.vapi.std.errors.internal_server_error) => { messages = [LocalizableMessage (com.vmware.vapi.std.localizable_message) => { id = vapi.bindings.method.impl.unexpected, defaultMessage = Provider method implementation threw unexpected exception: com.vmware.vapi.std.errors.InternalServerError, args = [com.vmware.vapi.std.errors.InternalServerError] }], data = } I was getting the........

OpenVPN error ERROR: Cannot ioctl TUNSETIFF tun: Operation not permitted (errno=1)

This basically means that you are running as non-root and you need to be root to create the tun0 or tap0 device on OpenVPN. You could try sudo or adding the openvpn binary to the list of sudoers.........

Cannot create gradle for conversations

The main issue is it looks like Java is not configured to accept the invalid ssl cert that is coming from the download location. Exception in thread "main" java.lang.RuntimeException: javax.net.ssl.SSLException: java.security.ProviderException: java.security.InvalidKeyException: EC parameters error export ANDROID_HOME=/home/user/Downloads/tools/ Conversations-master$ ./gradlew Downloading https://services.gradle.org/distributions/grad........

not allowed to execute '/usr/bin/apt-get install eclipse' as root linux sudo user permisson issue and solution

This is most likely to happen on a normal GUI system like Ubuntu or Linux Mint. If you or the user is meant to have sudo / root privileges it is as simple as editing the following files: Now assume your username is "iamtheuser" vi /etc/group adm:x:4:syslog,iamtheuser sudo:x:27:anotheruser,iamtheuser Find the above lines and add a comma and "ia........

Database Error One or more of the WHMCS database tables appear to be either missing or corrupted. Please check and repair. - WHMCS Solution

Database Error One or more of the WHMCS database tables appear to be either missing or corrupted. Please check and repair. This error can be misleading especially if you know you are using a known good backup or restoration of the WHMCS database. The error can also be that the user lacks permissions to read and write to the database. To check to this in MySQL shell: GRANT read,write to dbusername@localhost on dbna........

postfix errors fatal: no SASL authentication mechanisms /usr/libexec/postfix/smtpd: bad command startup -- throttling solution

Jul 3 22:12:17mailserver postfix/smtpd[6195]: fatal: no SASL authentication mechanisms Jul 3 22:12:18mailserver postfix/master[4881]: warning: process /usr/libexec/postfix/smtpd pid 6195 exit status 1 Jul 3 22:12:18mailserver postfix/master[4881]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling This only ever happens in my experience when the authentication method is actually Dovecot. Usually the problem........

error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file Bitcoin Litecoin Error

error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file This is usually because the .cookie file cannot be read by the user you are running Litecoin or Bitcoin client/daemon as. You can adjust the permissions of the file so that the user or group they are apart of has read permissions. ........

/usr/bin/supermin-helper exited with error status 1. To see full error messages you may need to enable debugging. See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs at /usr/bin/virt-list-partitions line 177.

virt-list-partitions kvmusertest.img /usr/bin/supermin-helper exited with error status 1. To see full error messages you may need to enable debugging. See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs at /usr/bin/virt-list-partitions line 177. #solution update-guestfs-appliance........

ffmpeg Linux Mint download, compile and install howto

#if you have nvidia make sure you install the nvidia-cuda-toolkit so hardware acceleration can be used wget http://ffmpeg.org/releases/ffmpeg-3.3.2.tar.bz2 tar -jxvf ffmpeg-3.3.2.tar.bz2 cd ffmpeg-3.3.2/ ./configure --disable-yasm install prefix /usr/local source path ........

Track 01: 34 of 1726 MB written (fifo 100%) [buf 99%] 3.6x.Errno: 5 (Input/output error), write_g1 scsi sendcmd: cmd timeout after 1.897 (40) s CDB: 2A 00 00 00 44 A9 00 00 1F 00 resid: 6144 cmd finished after 1.897s timeout 40s write track da

These errors believe it or not are simply because of not being the root user or running with sudo! However if you didn't know to try as root you'd think there was a problem with your burner or disc Essentially it looks like without root you cannot send the required scsi commands to continue writing. Ithink cdrecord should have built-in tests or safeguards to see if it has the permissions to run the required commands. I guess for more advanced users the idea is simila........

xdebug easiest howto get going

Just make sure you have php-xdebug installed and edit your php.ini: [xdebug] xdebug.profiler_enable = 0 xdebug.profiler_enable_trigger = 1 xdebug.profiler_output_dir = "/tmp/xdebug/" xdebug.output_name = "cachegrind.out.%t-%s" Also make and set permissions on /tmp/xdebug: mkdir /tmp/xdebug chmod 777 /tmp/xdeb........

sshd[10470]: Authentication refused: bad ownership or modes for directory /root

This can be a case of bad permissions or modes as the error says. Normally one would assume permissions but often a script may change ownership of /root to something else. This was the case half the time I've encountered this. So in short make sure ownership is correct chown -R root.root /root........

The connection was reset The connection to the server was reset while the page was loading.

In Firefox I cannot connect to any website, proxy is disabled and outside network access is confirmed, no system or manual proxy was set on this Linux Mint/Ubuntu system. Normally this can be caused by proxy or DNS problems and the weird thing is that traceroute and ping to other IPs worked fine but even connecting to sites by IP was not working. The connection was reset The connection to the server was reset while the page was loading.........

Avocent 8020 KVM Java Icedtea Viewer

This command in Debian/Ubuntu/Mint will get everything need installed for most Java based KVM viewers: sudo apt install icedtea-netx The following additional packages will be installed: ca-certificates-java icedtea-netx-common openjdk-8-jre openjdk-8-jre-headless It seems every other updated version of Java or Icedtea breaks things and I will save the frustration of Java for another post.........

bash script Get Model and Serial Number of All Hard Disks in Server on Linux

for disk in `fdisk -l|grep "Disk /dev"|awk '{print $2}'|sed s/://g`; do echo "$disk" && smartctl -d ata -a "$disk" -T permissive|grep -iE 'Device Model:|Serial Number:' echo "---------------" done *Make sure you have smartctl from smartmon tools installed Sample output: /dev/sdc Device Model: ........

Centos cannot login by console or ssh session closed immediately

In my case I could login with the initial install but I rsync'd everything over while preserving ownership and permissions to another RAID partition and booted from that.was fine before. The problem is that you are kicked out the second you login and the problem was SELINUX for some reason (perhaps it noticed something strange when it was moved to the new partition) login: pam_unix(login:session): session opened for user root by LOGIN(uid=0) login: ROOT LOG........

clamav freshclam out of date won't update solution

freshclam ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check permissions!). ERROR: Problem with internal logger (UpdateLogFile = /var/log/clamav/freshclam.log). Tue Oct 13 13:49:35 2015 -> WARNING: Incremental update failed, trying to download daily.cvd Tue Oct 13 13:49:35 2015 -> WARNING: Can't download daily.cvd from db.local.clamav.net Tue Oct 13 13:49:35 2015 -> Trying again in 5 secs...........

Error code: ssl_error_rx_record_too_long

An error occurred during a connection to site.com. SSL received a record that exceeded the maximum permissible length. (Error code: ssl_error_rx_record_too_long) The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem. When the above happens in our experience it is a misconfiguration of........

Disable linux bash proxy ENV export variable

if you type Export and see something like this: declare -x all_proxy="socks://127.0.0.1:22000/" Most sites assume and tell you to check your .bashrc or /etc/profile /etc/bash.bashrc which may not apply if you've unknowingly or forgot that you setup a proxy from your GUI such as Gnome. To check in Gnome if you have a permanent proxy do the following: System -> Settings -> Network Proxy........

Vbox/Virtualbox devices grayed out for non-root user solution

It is a permissions issue that is hard to fix. All but one USB device is greyed out. I am already a member of "vboxusers" I have already enabled and disabled USB support for the guest. I have already reinstalled the latest VBOx guest editions If running as root it all works fine Changing........

How to root and unlock S4 in Canada Bell/Rogers/Telus/Fido I337 4.4.2

i337 Canada on Bell is hard to root or even install TWRP Installed TWRP from Odin and my computer gave me the bluescreen at the end but it seemed to be successful (after ODIN said reset). TWRP mode does not seem to enter, instead you get the Android recovery mode with Volume up + Home http://galaxys4root.com/galaxy-s4-root/how-to-root-att-or-verizon-galaxy-s4-on-android-4-4-2/ 1.)........

Postfix how to secure outgoing authenticated e-mails for privacy and hide the IP address, mailer and other things

The most common solution is to use the /etc/postfix/header_checks but this is a big problem. Why is header_checks a problem? Because it does it to all mail whether incoming or outgoing and whether authenticated or not. We of course want as much header information for incoming as we can get for many reasons but many organizations want to secure and make their mail clients as secure as possible. I adapted this solution to the client's custom config, they are configur........

phpBB guests unable to view forums without logging in Anonymous account solution

This is still a weird quirk about phpBB, you can allow everyone+guests to see a forum. What also controls the first layer is this weird built-in "Anonymous" account. You have to actually give that account specific rights to view all the forums or otherwise the above will happen and you'll wonder why your group permissions don't seem to apply.........

CPanel Apache httpd won't start solution: Starting httpd: Syntax error on line 2 of /etc/httpd/conf/httpd.conf: Invalid command 'Alias', perhaps misspelled or defined by a module not included in the server configuration

root@hkhosting [/]# service httpd start Starting httpd: Syntax error on line 2 of /etc/httpd/conf/httpd.conf: Invalid command 'Alias', perhaps misspelled or defined by a module not included in the server configuration ........

Setting Ulimit

I never found a solution to do it live (nothing worked that I found) so it looks like a relogin is required. Check your maximum file limit cat /proc/sys/fs/file-max 824460 This is different than your actual's user limit which you'll see below ulimit -n 1024 Try and set it higher but it won't work ulimit -n 65000........

[emerg] (28)No space left on device: Couldn't create accept lock (/etc/httpd/logs/accept.lock.15449) (5) solution

[Wed Jan 08 18:50:07 2014] [emerg] (28)No space left on device: Couldn't create accept lock (/etc/httpd/logs/accept.lock.15449) (5) This may happen when trying to restart Apache and you find it dies right after starting and check /var/log/httpd/error_logs. What is the cause of this? You could be out of disk space (if you're not then see #2 and below) You're out of Semaphores, you need to kill all the old ones.........

Asterisk iptables block bruteforce attacks howto with fail2ban

yum -y install fail2ban vi /etc/fail2ban/jail.conf [asterisk-tcp] enabled = true filter = asterisk action = iptables-multiport[name=asterisk-tcp, port="5060,5061", protocol=tcp] sendmail-whois[name=Asterisk, dest=you@example.com, sender=fail2ban@example.com] logpath = /var/log/asterisk/messages maxret........

VBulletin Enhanced Captcha / RegSecure not showing/working images solution.

This happened after a customer migrated their hosting and the issue was being unable to access PHP sessions. Warning: session_start(): open(/var/lib/php/session/sess_3e0oms763m6mrqekdnnmodlhs3, O_RDWR) failed: Permission denied (13) in /register.php(202) : eval()'d code on line 1 Solution:(use the correct ownership/permissions) chown apache.apache -R /var/lib/php........

MySQL Error : Table 'datastore' is read only Error Number : 1036 solution

This happens because of a permissions or ownership issue. Generally /var/lib/mysql should be all owned by mysql.mysql (check that). To fix it use chown -R mysql.mysql /var/lib/mysql Also make sure the files are at least readable and writable by mysql (eg. 700).........

open /dev/kvm: No such file or directory failed to initialize KVM: Operation not permitted - Solution

open /dev/kvm: No such file or directory failed to initialize KVM: Operation not permitted [ 96.084502] kvm: disabled by bios Any of the above means that "Virtualization" is not enabled in your BIOS. Most servers and Desktops (non-mainstream) can do this no problem but leave it off by default. Note that some systems even though the CPU supports it, don't allow enabling of Virtualization for some reason (especially some lap........

SMARTCTL Enable SMART on Device Solution for Error "Device does not support SMART Error Counter logging not supported"

smartctl -a /dev/sda smartctl version 5.36 [i686-pc-linux-gnu] Copyright (C) 2002-6 Bruce Allen Home page is http://smartmontools.sourceforge.net/ Device: ATA WDC WD1600YS-01S Version: 20.0 Serial number: WD-WCAP03024940 Device type: disk Local Time is: Mon Apr 29 21:40:07 2013 PDT Device does not support SMART Error Counter logging not supported........

SSH Can't Login/Hang

Client Log OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to 192.168.1.253 [192.168.1.253] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/identity type -1 debug1: identity file /root/.ssh/id_rsa type 1 debug1: identity file /root/.ssh/id_d........

Kernel panic - not syncing: Attempted to kill init! Pid: 1,comm: init Tained: G I------------- 2.6.32-358.el6.x86_64 #1 Call Trace: [] ? panic+0xa0/0x16f [] ? do_exit+0x862/0x870 [] ? fput+0x25/0

Kernel panic - not syncing: Attempted to kill init! Pid: 1,comm: init Tained: G I------------- 2.6.32-358.el6.x86_64 #1 Call Trace: [] ? panic+0xa0/0x16f [] ? do_exit+0x862/0x870 [] ? fput+0x25/0x30 [] ? do_group_exit+0x58/0xd0 [] ? sys_exit_........

OpenOffice Writer Replacing/Reformatting Dates in Tables - Howto Disable

Tools -> Options -> OpenOffice Writer -> Table Uncheck "Number Recognition" This will permanently disable it but won't undo the damage it has already done. I spent a long-time fighting with this horrible feature which should be disabled by default.........

FBDIMM /PC5300F RAM chips can work properly be with mixed timing/speeds

I've read some people/sources say "the timing must match or it won't work". This is not true at least for the Supermicro boards I've tested this on. Some examples: PC2-5300F-555-12 PC2-5300F-555-11 etc.. Notice the "12" and "11" Also the ones that have a "PC2-5300F-555-11-B0" or "PC2-5300-555-11-D0" are also fine. What happens is what one would expect, the........

kvm cannot boot xen guest using lvm

This booting error is because the Xen PV guest image uses the Xen kernel, this is not compatible with anything but a host running a Xen kernel. I did a kpartx -av virtual.img and then it created some partitions that showed up in fdisk. I mounted it and did a chroot into it and removed the xen kernel and installed a normal kernel but Xen still shows the same kernel in Grub (only the Xen one). This is strange but it seems like this Xen PV guest has some sort of hidden or........

Disable SELinux How To Tutorial Solution

Here is a quick script that works on most Centos versions to disable the virus/SELinux from blocking basic functionality. The first echo 0 statement disables SELinux instantly but it will still be enabled on reboot. The second line disables it permanently. #!/bin/bash #disable SELinux Immediately echo 0 > /selinux/enforce #disable SELinux Permanently sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config........

ioctl: Operation not permitted can't delete tunnel

When trying to delete a tunnel ip tunnel del tunl0 I get this message: ioctl: Operation not permitted........

Samsung Galaxy Note Upgrade to ICS 4.0 microSDHC card not detected/dataloss after upgrading - possible solutions

I backed up everything in the /mnt/sd_card directory thinking that some dataloss could occur for some reason but purposely left my microSDHC unbacked up thinking that "it won't touch that since it's external" and Samsung's and other manufacturers website even say this (that it won't be affected and not to worry etc). Apparently I was wrong, my microSD was "undetected" and asked to be formatted after the upgrade (there goes 3-months worth of family photos). No........

Joomla Error - JFolder::create: Could not create directory

JFolder::create: Could not create directory Plugin Install: Failed to create directory: This can occur when trying to upload content or when installing themes/templates. It's usually not a permissions issue per say but doing a 777 (which is very insecure) will fix it. But the real problem solution is that the owner of the files is different than the owner of the Apache process/server. Eg. if your Apache is running as user "apache........

Directadmin Enable SSL

It's really silly how DA doesn't enable SSL by default but is otherwise a stable, fast and secure control panel. Here's a copy and paste way of enabling SSL for Directadmin in just a few seconds: *setup SSL openssl req -x509 -newkey rsa:1024 -keyout /usr/local/directadmin/conf/cakey.pem -out /usr/local/directadmin/conf/cacert.pem -days 9999 -nodes That creates the public certificate and private key pair in the location Directadmin expects to fi........

SSH error slow login debug1: An invalid name was supplied Cannot determine realm for numeric host address - Solution

debug1: An invalid name was supplied Cannot determine realm for numeric host address debug1: Local version string SSH-2.0-OpenSSH_4.3p2 Debian-9etch3 debug1: An invalid name was supplied Cannot determine realm for numeric host address debug1: An invalid name was supplied A parameter was malformed Validation error Solution, disable auth from the ssh client (this is a client side error)........

LOG: MAIN PANIC failed to expand condition "${if eq {$authenticated_id}{}{0}{${if eq {$sender_address}{$local_part@$domain}{0}{${if match{$received_protocol}{N^e?smtps?a$N}{${perl{checkbx_autowhitelist}{$authenticated_id}}}{${if eq{$received_prot

I experienced this with CPanel's Exim after an auto-update (a Google of this error produces lots of complaints with few clear solutions). In this case I'll put the solution at the top. Run /scripts/buildeximconf to rebuild the Exim config and it should be fine after that. mail -vs "from test" user@dest.com < .bash_history LOG: MAIN cwd=/root 4 args: send-mail -i -v user@dest.com LOG: MAIN &........

Drupal/MySQL database error: PDOException: SQLSTATE[42000] [1044] Access denied for user 'db_user'@'localhost' to database 'dbname' in lock_may_be_available() (line 167 of /home/user/public_html/includes/lock.inc).

PDOException: SQLSTATE[42000] [1044] Access denied for user 'db_user'@'localhost' to database 'dbname' in lock_may_be_available() (line 167 of /home/user/public_html/includes/lock.inc). The username and password were correct but some reason CPanel added the user with no permissions! Edit the user's permissions to include "All" from Cpanel or MySQL and that is the solution.........

How To Burn ISO Image using cdrtools/dvdrtools for Linux/Unix Ubuntu/Debian/RHEL/Centos etc..

It really is as simple as: cdrecord -v dev=/dev/sr0 pathtoyourisoimage.iso -v is for verbose, I prefer it but if you don't you won't see as much output like below (I like to know the details and exactly what's happening) dev=/dev/sr0 specifies the device name of your burner (they say not to use it and to specify some weird annoying device string but using the raw /dev has always worked for me and is how it should have been implemented from the start IMHO)........

iPhone Restore/Backup Location of Notes and Contact/Address Book

*Make sure that the ownership is 501.501 or mobile.mobile when copying back (especially if using ssh or sftp as root on the iPhone) otherwise things will break. Eg. the contacts will be blank even after trying to update due to incorrect ownership/permissions. iPhone Notes Location/Restore: /private/var/mobile/Library/AddressBook AddressBookImages.sqlitedb AddressBook.sqlitedb Once you restore the contacts and restar........

vi disable color syntax highlighting/can't read syntax highlighting

Within vi if you can't exit /etc/vim/vimrc you can type :syntax off And to turn it back on: :syntax on Many of us have a dark/black background in our terminal/shell making the default syntax unreadable, the solution is to either turn off syntax highlighting with :syntax off or to enable a special option in /etc/vim/vimrc Edit /etc/vim/vimrc The "syntax on" enables the highligh........

samba/smbd connection to share problems and solutions

I'll start by showing some problems in the logs: [2011/08/07 16:22:06, 0] param/loadparm.c:8569(process_usershare_file) process_usershare_file: stat of /var/lib/samba/usershares/movie failed. Permission denied [2011/08/07 16:22:06, 1] smbd/service.c:676(make_connection_snum) create_connection_server_info failed: NT_STATUS_ACCESS_DENIED That means you don't have permission to access the fi........

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This assumes that you've at least created the correct partition for your DRBD already. Notice that I am "diskless", that's because either your DRBD partition doesn't exist/has been renamed (eg. sdb becomes sda when sdb dies and you reboot) or because that drive is really actually dead/gone. *If you need to permanently change the partition/device for your resource be sure to edit /etc/drbd.conf on both hosts and reload the config. (replace r0 with........

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yum -y install vnstat chown nobody.nobody -R /var/lib/vnstat/ #replace venet0 below with your desired interface sudo -u nobody vnstat -u -i venet0 #edit: vi /etc/sysconfig/vnstat #VNSTAT_OPTIONS="-i venet0" # only use the sed below if you are using venet0 instead of eth0 or replace accordingly sed -i 's/eth0/venet0/g' /etc/sysconfig/vnstat [root@monitor]# yum install vn........

phpMyAdmin - Error Cannot start session without errors, please check errors given in your PHP and/or webserver log file and configure your PHP installation properly.

The fix for this was setting the correct permissions in /var/lib/php, it needs to be "root.root" And /var/lib/php/session needs to be "root.apache" to work properly. After that I was able to login to phpMyAdmin as normal. This whole thing happened because I accidentally changed all of /var/lib to root.root.........

MYSQL Error Can't find file: './wf/Sessions.frm' (errno: 13) Solution

mysql errors even though these files do exist: 110405 13:21:37 InnoDB: Operating system error number 13 in a file operation. InnoDB: The error means mysqld does not have the access rights to InnoDB: the directory. InnoDB: File name ./ibdata1 InnoDB: File operation call: 'open'. InnoDB: Cannot continue operation. 110405 13:26:15 InnoDB: Operating system error number 13 in a file operation. InnoDB: The error means my........

monit example tutorial how to enable status checking and manipulation

You need to enable the httpd daemon with monit to actually view the status and control, it's not only for the web interface since the httpd is theONLY way of controlling monit and viewing the status. monit monitor all will also reinstate disabled services if they've timed out too much. Just restarting the service will do nothing to re-monitor a service that monit has stopped monitoring due to too many failures. *Also note that /etc/monit.conf i........

Drupal 6.2 Install and how to move install to root/non-subdirectory

drup 6.2 install $cd drupgoodinst3883/ [ drupgoodinst3883]$ ls CHANGELOG.txt cron.php index.php INSTALL.pgsql.txt INSTALL.txt MAINTAINERS.txt modules robots.txt sites update.php xmlrpc.php COPYRIGHT.txt includes INSTALL.mysql.txt install.php LICENSE.txt misc&........

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high IO wait 424 root 39 19 1900 848 552 D 0.0 0.0 0:00.91 updatedb root 424 0.0 0.0 1900 848 ? DN Mar11 0:00 /usr/bin/updatedb -f sysfs?rootfs?bdev?proc?cpuset?binfmt_misc?debugfs?sockfs?usbfs?pipefs?anon_inodefs?futexfs?tmpfs?inotifyfs?eventp........

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Convert MBOX Mail files into Maildir using Linux *You need perl an the TimeDate module Get the free Perl script mb2md from the project/author's site: wget http://batleth.sapienti-sat.org/projects/mb2md/mb2md-3.20.pl.gz gunzip mb2md-3.20.pl.gz #remember you need timedate or you'll get this error: ./mb2md-3.20.pl Can't locate........

Postfix Enable SSL/TLS with your certificate

Create Cert & Key: openssl req -new -x509 -nodes -days 1530 -out server.crt -keyout server.key mkdir /etc/mailssl chmod 700 /etc/mailssl cp server.* /etc/mailssl Postfix SSL config Edit /etc/postfix/main.cf: #SSL stuff smtpd_tls_cert_file = /etc/mailssl/server.crt smtpd_tls_key_file = /etc/mailssl/server.key To make smtps w........

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Forbidden You don't have permission to access / on this server. [Sun Jan 23 15:28:12 2011] [crit] [client 96.44.31.12] (13)Permission denied: /www/vhosts/domain.com/httpdocs/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable Solution I've done a chmod 755 .htaccess and index.php and restarted Apache That wasn't the only issue, the issue was the httpdocs direc........

Ubuntu 9.04 Crash

CPU/Kernel/MB/RAID problem? Jan 5 12:45:05 testbox kernel: [653298.890004] BUG: soft lockup - CPU#0 stuck for 61s! [hal-acl-tool:4168] Jan 5 12:45:05 testbox kernel: [653298.890005] Modules linked in: vmnet vmci vmmon binfmt_misc drbd video output input_polldev ocfs2_stackglue ocfs2_dlmfs ocfs2_dlm ocfs2_nodemanager configfs k8temp hwmon_vid lp snd_hda_intel snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi........

SSH delay problem UseDNS and disabling GSSAPI does not help

The normal solution doesn't help or apply here: ssh -v user@192.168.5.41 OpenSSH_4.3p2 Debian-9etch3, OpenSSL 0.9.8c 05 Sep 2006 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to 192.168.5.41 [192.168.5.41] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/identity type -1 debug1: i........

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Install the "Editors" and "Net" groups that will give you rsync, ssh, ssh-keygen and cron. The trickiest thing that I keep forgetting about each time is you have to run "cron-config" which adds the cron service to Windows, and without doing that obviously no cron jobs will be run thus making automatic backups impossible. Warning about rsync/cygwin and using the -a archive switch. It's a good thing I caught this because it doesn't work ri........

rsync preserve attributes, permissions/ownership and times without being root non-root user

One of the purposes of rsync is to backup whole filesystems and archive them but how can you do that properly and restore things to normal if all permissions and ownerships are not preserved from your root filesystem? It's not desirable to have everything running as root, especially not just for an rsync. The Easy rsync preserve permission solution for non-root users sudo is the answer and all you have to do is edit /etc/sudoers At the end o........

How to Enable SMART on a device

smartctl -a -d ata -T permissive --smart=on /dev/sda -d ata is usually required for most SATA drives or you get an error. -T permissive is required if it's the first time you are running SMART on this device (it's not enough just to enable SMART in the BIOS) --smart=on is also required for the first time........

Local policy does not permit you to log on interactively. - Solution/Fix

For a standalone system the solution is simple, just use the same version of Windows a copy a good version of: C:windowsSecurityDatabasesecedit.sdb from another computer. Then you should be able to login again without getting the nasty message "Local policy does not permit you to log on interactively." Of course you will probably need a way of accessing the filesystem off-line in order to get to it such as a Linux boot disc. Some........

Linux Burn MP3 CD On the Fly using

I finally decided to look into some utils that did this, and the first one I found is "mp3burn". It is unbelievable simple and perfect. *2017-11 update and mp3burn is still available in standard repos such as Ubuntu 14/16 so this is a current and working project. Just install the package and it gets all required libraries to convert and then burn's on the fly. And you won't believe how simple it is. I just want to a directory that had the MP3's I wanted t........

FUSE/Curlftpfs mount ftp account as drive partition in Linux

This is a great way to use your ftp server space, for example on your web hosting account (althoughI believe many hosts don't allow storage like this), but if you have a VPS/Dedicated Server etc.., this would be perfect. Imagine how easy it is to work with an ftp account that you can just mount as a normal partition or directory in Linux, it would be great for backups etc.. Name curlftpfs - mount a ftp host as a local directory Synopsis........

mdadm force/fix proper md127 name

I have an md0 arary that my Centos install refers to. I feel this is half the reason why it won't boot anymore. I saw the initrd for Centos was assembling it as md127 even though it was known as md0. The reason for this is because I used mdadm --assemble --scan to detect the array on a LiveCD. I had no idea this name would stick (but now I realize the name is permanently stored in the metadata once you mount md127 or whatever random name assemble gives it). W........

SSH Automatic/Passwordless Logon - Setup Public Key Encryption In Single Command

This is a very simple solution, but most guides out there make you login twice (once to scp the key) and once to put the key in authorized_keys. There's no need for that. If you don't already have a ~/.ssh/id_rsa.pub just type "ssh-keygen -t rsa" and keep hitting enter until it's done :) Just use this code to easily enable passwordless login with SSHD key=`cat ~/.ssh/id_rsa.pub`;ssh user@192.168.5.25 "echo $key >> ~/.ssh/auth........

rsync my favorite/best/optimal default switches and options

Not sure what rsync switches/options to use? rsync -PDrphogtl The short version would be: rsync -Pha I think these are really common sense options to use and probaby should be the default. Explanation of rsync switches P = display the progress D = hybrid of --specials and --devices so all special and device files will be copied as well. r = recursive (otherwise rsync won't copy files deeper than........

PHP cannot access /usr/bin/openssl

PHP cannot access /usr/bin/opensslI have verified the username that runs the process is able to access /usr/bin/openssl and it does exist but the PHP script is saying it doesn't exist: [code:1:1fd0f3abbe] if (!file_exists($OPENSSL)) { //echo "ERROR: OPENSSL $OPENSSL not foundn"; }[/code:1:1fd0f3abbe] I don't get itI can clearly see the contents of /usr/bin by using the PHP system fu........

CentOS (most Linux) no-RAID to software RAID-1 guide

CentOS (most Linux) no-RAID to software RAID-1 guidehttp://lists.centos.org/pipermail/centos/2006-January/018624.html........

Helpful IPFW Examples

Helpful IPFW ExamplesSomeone's real life examples: http://lists.freebsd.org/pipermail/freebsd-security/2004-July/002181.html Or you can try the FreeBSD Handbook guide: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/firewalls-ipfw.html........

SATA Power cable for 1U Server Solutions - Rosewill 8" SATA Power Cable Model RC-8"-PW-4P-2SA

NewEgg is one of the few companies that stocks this great right angle 1U SATA power cable. I've purchased some no-name ones and they face the wrong way (towards the bottom of the chassis) which makes it worse/impossible than standard SATA connectors. The price is high but if you're building a 1U server and want SATA disks and don't have much space (eg. the 1U Supermicro cases) then these are simply a must and........

MySQL Error "ERROR 1045 (28000): Access denied for user"

This happened with a select statement which writes the result to an external file. I didn't remember the privilege "FILE" must be granted on *.* for this to work successfully, it wasn't actually an authentication issue as it implies since I was already in the SQL prompt and doing the query. SELECT some_id FROM sometable INTO OUTFILE '/tmp/result.txt'........

SSH Slow Login even with SSHD UseDNS no parameter

Icouldn't understand why on one system it took a few minutes to get the SSHlogin prompt when connecting to other systems. The other systems all had the UseDNS parameter set to no, which almost always resolves the login prompt delay. The reason is Ubuntu and perhaps Debian and other distributions /etc/nsswitch.conf file Edit yours to have the "hosts" line like so (notice that files and dns are the primary resolution choice........

OCFS2 crash

When trying to even cd or ls the mounted OCFS2 partition it crashes. Ithink this is a combination of VMWare Server's problem and the way I mounted and symlinked to it. More than anything this shows the problem and lack of forsight with VMWare, but also that OCFS2 is easily crashed if you do strange things. Output of /var/log/messages for OCFS2 Apr 10 15:57:45 localhost kernel: [84331.691258] Modules linked in: vmnet vmci vmmon ocfs2_stac........

Viewing and Connecting to an SMB Samba Share on Windows/Linux/Unix

This will give you the basic info needed to browse and connect to Samba shares from the command line. From the GUI of Gnome or KDE etc, it is pretty standard and straight forward. However, I've found very little guides on how to do it from the command line and if you're like me, a nerd who prefers command line for its simplicity and for remote use, this is the way to go. First get a list of all the Samba/SMB shares on the target. smbclient -L hostname........

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Ithink there has been a lot of negative press towards Rackable Systems. We will give their new solution credit that it is marketed very well, and comes prepackaged and ready to go. But let's cut through the hype of both sides, the people who love this concept and the people who hate it. What Rackable Systems have done is a first, to minimize space, power and costs into small servers. This is great, and many companies have already built their own servers based........