The Best Docker Tutorial for Beginners We quickly explain the basic Docker concepts and show you how to do the most common tasks from starting your first container, to making custom images, a Docker Swarm Cluster Tutorial, docker compose and Docker buildfiles.........

This guide assumes that you are trying to connect to a corporate network. First of all you need to define what IPrange the OpenVPN server will be running on. Network Option 1.) There are a few options, such as the OpenVPN sitting exclusively on the internal network, with the port and protocol that the server is used on being forwarded to this via the router and/or firewall. Network Option 2.) The OpenVPN server could sit on both th........

How To Install Wazuh Server Wazuh (forked from the well known OSSEC project) is a full SIEM (Security Information Event Management) that works extremely well with the platforms it natively supports as an "Agent", which allows you to do scans of everything such as all processes running, CVE vulnerability check, incident reporting etc... This is the easiest way: The unattended install makes things a breeze to........

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........

mysql reset root password. Oops I can't remember my MySQL root password! [root@centos7test etc]# mysql -u root -p Enter password: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) First we need to stop mariadb: systemctl stop mariadb Now we need to restart it with skip-grant-tables whic........

It is much more useful to have meaningful and detailed logging from tftp to see what is or isn't happening especially for VOIPand other embedded device appications: Edit the file: vi /etc/xinetd.d/tftp Change the server line like this: server_args = -s /var/lib/tftpboot........

This is usually because the Group Policy forbids that user or group from logging in. run "gpmc" (not "gpedit.msc" as that is for local computer settings when you are not using Active Directory) or go to Administrative Tools and Group Policy Management. Edit the default domain policy like below........

00:55:07: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down 00:55:09: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up Switch(config)#no logging console ........

A lot of people just have a -j DROP to drop all unwanted traffic or traffic not explicitly allowed but there is a better solution if you want real and proper logging: Take an example iptables rules file -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -i eth1 -p icmp -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -i eth1 -j ACCEPT -N LOGGING -A INPUT -j LOGGING -A LOGGING -j LOG --log-pre........

sudo apt-get install libcurl4-openssl-dev git build-essential autotools-dev autoconf libcurl3 sudo apt-get install libcurl4-gnutls-dev git clone https://github.com/wolf9466/cpuminer-multi sudo apt-get install cmake libpthread-* libmicrohttpd-dev libssl-dev libhwloc-dev git clone https://github.com/fireice-uk/xmr-stak-cpu.git make install cd bin chmod +x xmr-stak-cpu ./xmr-stak -O xmr........

This is not the normal "black screen"issue and I was shocked to eventually find out why. The normal advice of reconfiguring Xorg didn't work. Even booting into "Recovery Mode" did not help. Here is the short end of the stick that fixed it: sudo apt-get install mdm mate-desktop-environment Yes you got it right, mdm and the mate-desktop-environment / gnome were somehow uninstalled. This must be whe........

This is mainly the case on Centos but applies to other distros and situations. If you are running programs in the background with the &, at least in Centos it is usually not honored and if you quit or are disconnected the backgrounded programs will be sent sighup and be shut down. The simplest way around this instead of using & is to start any programs or commands with "nohup" Eg. nohup yourscript.sh........

Using Apache 2.2 and PHP5.6 PHPBB3 is very slow to respond. Actually for some reason it takes so long to even register a log entry in access_log as in several seconds or a few minutes later it shows up in Apache. All other vhosts and Apache access stops working and freezes until the request to access PHPBB3 slowly completes. It seems to randomly be slow if you stop using it whether for posting or reading the forums. I've migrated to different machines including........

170110 5:35:23 [Note] /usr/libexec/mysqld: Normal shutdown 170110 5:35:23 [Note] Event Scheduler: Purging the queue. 0 events 170110 5:35:23 InnoDB: Starting shutdown... 170110 5:35:24 InnoDB: Shutdown completed; log sequence number 0 12765401 170110 5:35:24 [Note] /usr/libexec/mysqld: Shutdown complete 170110 05:35:24 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended........

service named status rndc: connect failed: 127.0.0.1#953: connection refused named (pid 10557) is running... Check /var/log/messages: Jan 4 17:06:22 storagebox named[10753]: none:0: open: /etc/rndc.key: permission denied Jan 4 17:06:22 storagebox named[10753]: couldn't add command channel 127.0.0.1#953: permission denied Jan 4 17:06:22 storagebox named[10753]: non........

I still cannot understand how this would not be enabled by default and I struggled to find the reason why with manually installing samba etc.. wondering why the option for sharing was not in the menu. On Linux Mint "MATE" the package is called "caja-share" and on Cinnamon it is called "nemo-share" so edit the below command as necessary: *Also note that the "samba" package is necessary as it is not inst........

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.........

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........

Another new drive bad from the start: Jun 2 15:14:18 one-desktop kernel: [15895.386779] ata2.00: exception Emask 0x50 SAct 0x1 SErr 0x280900 action 0x6 frozen Jun 2 15:14:18 one-desktop kernel: [15895.386782] ata2.00: irq_stat 0x08000000, interface fatal error Jun 2 15:14:18 one-desktop kernel: [15895.386784] ata2: SError: { UnrecovData HostInt 10B8B BadCRC } Jun 2 15:14:18 one-desktop kernel: [15895.386788] ata2.00: cmd 60/0........

This is just trying to read 5GB off the drive with dd and the drive initially tested ok but shortly after I wondered why I was seeing 2MB/s read speeds. Notice the "current_pending_sector", anytime I've seen it at anything above 0 even with no other bad fields/attributes, it means the drive is bad. ata1.00: exception Emask 0x0 SAct 0x3 SErr 0x0 action 0x0 ata1.00: irq_stat 0x40000008 ata1.00: failed command: READ FPDMA QUEUED ata1.00: cmd 60/00:00:........

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........

Here's a proven example of what a bad hard drive can do, it was technically functioning OKin a RAID array but the system became extremely low and the load become high and IOWAIT was even higher and I always thought it was a bad application. The truth is that this failing 1TBHitachi has slowly gotten worse and caused huge slowdowns, (eg. 100% load on Thunderbird waiting for e-mails to load etc..). After swapping it out, tabs change instantly, emails are not lagged, and........

I like dd, although it only reads it, usually a read test of the entire disk will uncover if your hard drive is bad in some parts. This is a good thing to do at least once a month, a lot of times bizarre program behavior, laginess and crashing/unnmounting problems etc.. are due to a failing disc and SMART won't know it or indicate a problem: We must also remember there's never a guarantee, I've found that ever since we moved to larger and more platters per drive with 1TB drives........

I had a dying drive that smart thought until it totally disappeared was a good drive, and actually all parameters did look fine but this system was causing my system to lockup and other bad behavior: === START OF INFORMATION SECTION === Device Model: WDC WD20EARS-00MVWB0 Serial Number: WD-WMAZ20139 Firmware Version: 50.0AB50 User Capacity: 2,000,398,934,016 bytes Device........

I had one of these shipped and it was not recognized when plugged in, here's what a dead drive looks like (I assume it's teh circuit board which is dead): ata1: link is slow to respond, please be patient (ready=0) ata1: softreset failed (device not ready) ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) ata1: link online but device misclassified, retrying ata1: link is slow to respond, please be patient (ready=0) ata1: softreset f........

One thing to note about DNS servers and providers is that they aren't always trustworthy, not even if they're Google or your favorite ISP. Any DNS server can compromise your privacy, and they are likely tracking your browsing habits and keeping logs of it. Sometimes it's for Marketing/Research purposes such as Google's GMail service which they admit is scraped/datamined. I would expect nothing less from their DNS service. The other danger with such widely used and pu........

If you have a webserver and find you have high IO/lagginess MySQL is one of the first things to check. It turns out MySQL was my problem and it was creating a high load on my server, especially for IO. How to Enable MySQL Slow Query Logging To Find Slow Performance/Queries vi /etc/my.cnf Add this anywhere under [mysqld] #slow queries log-slow-queries = /var/log/mysql/mysqlslowqueries.log long_query_time = 1........

mod_status is a great way to track down the source of high CPU usage and to find what vhost/script is the cause of it. It gives you a live view of bandwith usage, CPU usage, and memory usage broken down by domain/vhost and script/URI. Enable mod_status vi /etc/httpd/conf/httpd.conf ExtendedStatus On SetHandler server-status Order Deny,Allow Deny from all All........

Let the numbers speak for themselves, from what I read the Load_Cycle_Count which is very high (more than 500,000/half a million times) is the number of head parks. What a stupid"Green" design and design flaw which will probably mean an early life for the drive. This is almost as silly as Seagate's new reputation for BSY/poor quality disks since the 7200.11 series. To make it worse this is also when Western Digital introduced "Advanced Format" o........

This drive is clearly on the way out, the Kernel knows it but I'm surprised that SMART is not concerned. I didn't blame Seagate for their past issues until now. This hard drive has hardly been used and has not even been powered on for a year according to SMART. Home page is http://smartmontools.sourceforge.net/ === START OF INFORMATION SECTION === Model Family: Seagate Barracuda 7200.11 Device........

Seagate Inventory/Firmware Check I heard about this issue a long time ago but never looked into it. I figured I wasn't affected since my 500GB drives were running for so long. I've been using Seagate's since 2002 and to this day all of the drives I have are alive from Seagate. *Update the bad news is that I realize one of my 500GB's is about to die, it's not even a year old, but is also not affected by the recall according to Seagate! Seagate Inventory/Firm........

It's basically free bash shell script available from: http://wpkg.org/email2fax/index.php/Main_Page Make sure you have the required tools: libtiff ghostscript mpack/munpack Where you can e-mail your Asterisk box and it will fax it to the phone number in the subject line. The good news ends there, it is fairly undocumented and buggy. Take for example how the documentation mentions you can invoke from the com........

This is really something the SSHServer developers should consider. The cause of this annoyance is because of failed DNS lookups on your IPaddress, which is especially common for many dedicated/col-located servers and also computers on internal NAT/private networks. The chances are this is the cause of your SSHSlow/Delayed Login problems. The easy solution to SSH Login Problems Edit /etc/ssh/sshd_config Add this line to disable r........

Server not using user level security and no password supplied. tree connect failed: NT_STATUS_WRONG_PASSWORD That happens when trying to use smbclient to connect to a share. The weird thing is that I can authnenticate just fine from Windows XP. It is partially my mistake, I forgot this share does have a password. I've tried authenticating with the correct user and also with "Guest" because this works in Windows. In Linux I ........