Have you ever tried mounting a partition that you exists but you get this error?
mount: /mnt: can't read superblock on /dev/sda1.
The superblock in this example was bad because the physical disk had corruption and bad blocks/sectors. However, the data was generally accessible and you can always try this trick below (with caution and no warranty).
This is specifically for filesystems that place superblocks in multiple locations, which........
A lot of companies are unsure which solution to choose and many may not be aware of Docker Swarm as an alternative to Kubernetes. One thing that many Sysadmins find is that Docker Swarm is simply easier, quicker to setup and maintain by far than Kubernetes.........
Step 1.) Upgrade to Debian 11 first
The process to go to Debian 12 is not as smooth as 11, when trying to upgrade from Debian 10. In fact, it doesn't work directly, so you'll first need to follow this guide to update to Debian 11, reboot and come back here if successful.
Step 2.) Update sources.list
Update your /etc/apt/sources.list like this:
deb http://........
This is an ongoing issue even with the latest Thunderbird 102.x where attachments downloaded via IMAP just won't save or will be corrupt which is a huge interruption to workflow or if you come back later to find out the file you thought you saved is invalid/corrupt and you have perhaps deleted the e-mail.
How to solve the Thunderbird filesize attachment issue?
1. Click on "Settings". then go to "General".
2. Scroll to the bottom to find "Conf........
Just use apt-cache policy to find the repo of a package:
apt-cache policy lxd
lxd:
Installed: 3.0.3-0ubuntu1~18.04.2
Candidate: 3.0.3-0ubuntu1~18.04.2
Version table:
*** 3.0.3-0ubuntu1~18.04.2 500
500 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
&nb........
There aren't too many simple guides that show you how to use commands to setup your USB or other drive as a normal bootable drive where you can easily boot custom kernels or whatever OS you would like.
1. Get the tools we need:
We install "syslinux" for MBR and "syslinux-efi" for EFI and "MBR" as we need a tool that embeds the actual MBR into our USB:
sudo apt install syslinux syslinux-efi mbr........
This is sure simple if you follow the guide but it took a lot of hacking around to make this work on Debian/Ubuntu!
Now before you ask why bother running wine and python, the reason is because Python executables are NOT cross-platform. If you run pyinstaller in Linux, that binary will only run on Linux and the same if you do it in Windows. So it is preferable if you have a single environment that you can create Linux and Windows binaries from rather than running 2 separate........
The reason for doing this is that the installer doesn't seem to work properly for LUKS and the server installer doesn't even support LUKS anymore. When you use the GUI install on Desktop for LUKS it won't boot and will just hang after you enter your password. So the only reliable way is to do it ourselves.
1.) Make a default minimal install of Ubuntu
2.) Have a secondary disk on the server or VM.
3.)........
The cool thing here is that we only need 1 drive to make a RAID 10 or RAID 1 array, we just tell the Linux mdadm utility that the other drive is "missing" and we can then add our original drive to the array after booting into our new RAID array.
Step#1 Install tools we need
yum -y install mdadm rsync
Step #2 Create your partitions on the drive that will be our RAID array
Here I assume it is /dev........
SSH helps keep us secure in many ways, one of those is the host-key fingerprint which is unique. If you have been connecting to an SSH server that you've made no changes to and suddenly ssh warns that the key doesn't match then you have a problem.
But how about connecting to an existing server for the first time on a new machine or client?
A lot of new clients calculate it using an SHA256 hash but it is not as easy on your host machine to produce the sam........
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........
[root@localhost:~]
BootModuleConfig.sh echo host-ind nfcd........
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........
dvd+rw-mediainfo /dev/sr0
INQUIRY: [ASUS ][BW-16D1HT ][3.00]
GET [CURRENT] CONFIGURATION:
Mounted Media: 11h, DVD-R Sequential
Media ID: RITEKF1&n........
Ialready have the caja-image-converter option installed but it shows nothing.
Weirdly enough if you install nemo and nautilus converter it does show and work inside caja:
The solution is to install *-image-converter
sudo apt-get install *-image-converter
Reading package lists... Done
Building dependency tree
Reading state information... Done
Note, selecting 'n........
#mount the VCSA DVD
mount /dev/sr0 /mnt/cd
#alternatively you could mount the iso directly
mount -o loop vcsa.iso /your/mount/path
#for this purpose we are using the CLI installer on Linux
cd /mnt/cd/vcsa-cli-installer/lin64
#no it's not going to be that easy you can't just run vcsa-deploy like that you need to use a template or configured .json file
./vcsa-deploy
Usage: vcsa-deploy [-h] [--version] [--supported-deploymen........
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........
To get the first X letters of a word:
It's very simple you can just pipe it to head with
-c 1 (gives the first letter and so on)
-c2 (2 gives the first 2 letters).
echo "dsjfsdlksjdklf;jlsd;kflasdj;kl"|head -c 2
Returns ds
To get the last X letters of a word:
Now we use tail with -c but it works differently. ........
I believe from what I've read that this card's driver doesn't support the features after trying all known troubleshooting methods.
ffmpeg -i uservideoRendered.mp4 -filter:v hwupload_cuda,scale_npp=w=1920:h=1080:format=nv12:interp_algo=lanczos,hwdownload -c:v hevc_nvenc -profile main -preset slow -rc vbr_hq -c:a copy uservideoRendered.mp4-test
ffmpeg -i uservideoRendered.mp4 -filter:v hwupload_cuda,scale_npp=w=1920:h=1080:format=nv12:interp_algo=lanczos,hwdownload........
Done on Centos 7.3 very important as clearly based on older guides it was a lot easier and more simpler! Hint do not use grub2-install!
If you have trouble booting after this check this CentOS mdadm RAID booting/fixing guide.
One huge caveat if you are an oldschool user or sysadmin who has avoided UEFIbooting
The nor........
This is a 8TB Seagate external USB 3.0 device apparently newer kernels use a module called "UAS" instead of "USB Storage" which causes issues as a lot of devices are not properly supported in UAS mode by the kernel driver. The solution some say is to disable UAS specifically for your USB device but I'd rather just disable UAS altogether.
Solution blacklist UAS: *do not do this it does not work and just causes your USB 3.0........
Based on this tutorial: http://www.linuxjournal.com/content/overlay-images-video-using-mplayer-and-mencoder
mencoder -oac pcm -ovc raw -vf bmovl=0:0:tfifo -o $output $file
vf_bmovl: Unknown command: ''. Ignoring. ........
1.) Replicate the number of partitions in your new drives.
gdisk /dev/sda
gdisk /dev/sdb
I created 3 partitions of the same same size.
partition #1: +1G (/boot)
partition #2: +60G (swap)
partition #3: rest of it (/)
#note if you are using GPT/gdisk you need to create separate a partition at least 1MB in size (in my case I would a 4th partition and mark it type ef02).........
Uh oh
[17925926.174277] block drbd0: Handshake successful: Agreed network protocol version 96
[17925926.174325] block drbd0: conn( WFConnection -> WFReportParams )
[17925926.174342] block drbd0: Starting asender thread (from drbd0_receiver [1682])
[17925926.174432] block drbd0: data-integrity-alg:
[17925926.174581] block drbd0: drbd_sync_handshake:
[17925926.174586] block drbd0: self 2AAE66AF9252D6DB:2815BF........
Here is the scenario you or a client have a remote machine that was installed as a standard/default minimal Centos 6.x machine on a single disk with LVM for whatever reason. Often many people do not know how to install it to a RAID array so it is common to have this problem and why reinstall if you don't need to? In some cases on a remote system you can't easily reinstall without physical or KVM access.
So in this case you add a second physical or disk or already ha........
# first we need a physical volume which we use the pvcreate tool to create
# I create mine on /dev/sdb3
pvcreate /dev/sdb3
dev_is_mpath: failed to get device for 8:19
Physical volume "/dev/sdb3" successfully created
# pvdisplay shows the newly created volume
pvdisplay
"/dev/sdb3" is a new physical volume of "1.35 TiB"
--- NEW Physical volume ---
PV N........
LSi Megaraid
At first it was configured as a RAID 0, then I deleted the Virtual Disk Group.
I thought both drives would be shown and detected in Linux as sda and sdb but it actually shows nothing.
To make them work you have to hit Ctrl+R before the system boots (when prompted) and create a Virtual Disk Group. In my case I created each one as RAID 0 (with a single drive only) as I just wanted JBOD but there is no such option or default in these Dell Pe........
yum update error
Traceback (most recent call last):
File "/usr/bin/yum", line 29, in ?
yummain.user_main(sys.argv[1:], exit_code=True)
File "/usr/share/yum-cli/yummain.py", line 229, in user_main
errcode = main(args)
File "/usr/share/yum-cli/yummain.py", line 145, in main
(result, resultmsgs) = base.buildTransaction()
&nbs........
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........
find what MPM Apache is using, it will either be using "worker" or "prefork"
apachectl -l
Compiled in modules:
core.c
prefork.c
http_core.c
mod_so.c
In my case it is "prefork"
vi /etc/httpd/conf/httpd.conf
Find the section that looks like this (by default one will normally exist for prefork and for worker, but in my case I only care a........
This really gives me a bad impression of SolusVM.
I tried the "Central Backup" option and it does not warn that your server gets shutdown instantly in order to do the backup!
Further, there is no way to pause or cancel the backup. Thankfully this is a test/small disk usage VPS but what if someone was running something production with a large filesize?
Ihaven't used QuickBackup but hope that isn't the same thing.
Everyone should be vary car........
This is based on Debian Linux but should apply equally to any *nix distro.
Install LUKS/crypt-setup
apt-get install cryptsetup
Setup your LUKS Partition
Of course change /dev/md2 with whatever partition you intend to use LUKS on.
cryptsetup --verbose --verify-passphrase luksFormat /dev/md2
You'll be asked to verify your decryption password twice
*DO NOT FORGET THIS PASSWORD AS IT IS NOT RECOVERABLE!........
I've never understood how to enable and disable services for different run levels in Debian based distros, it's just weird, annoying and doesn't make sense. I much prefer chkconfig from RHEL.
Just install the package called 'rcconf' and be done with it. rcconf makes things easy for you.
apt-get install rcconf
Reading package lists... Done
Building dependency tree
Reading state information... Done........
Before we start I take no responsibility for this, you should have a backup and if you make a mistake during this process you could wipe out all of your data. So backup somewhere else before starting this as a precaution, or make sure it's data you could afford to lose.
The RAID 1 Setup (Hardware Wise)
I've already setup my 2 x 1TB (Seagate) drives with identical partitions, make sure your new hard drive (the empty one) is setup like your curr........
I have no idea why but mkfs.ext3 defaults to a patheticlly small blocksize of 1024 bytes/1KB (kilobyte). That means the maximum filesize is ONLY 16GB! With 2KB/2048 bytes you get a 256 GB maximum filesize, and with 4KB/4096 bytes you get 2TB!
I finally noticed/paid attention to this after realizing that with rsync and scp that no file larger than 17GB could be transferred. I then realized it must be a file size limit on the partition.
Here is what tune2fs tol........
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........
There's a lot of information and guides on OCFS2 for RHELand Centos Linux but the package setup and configuration is slightly different and this has thrown some people off.
Installing OC2FS
You should install the following packages to get started:
apt-get install ocfs2-tools ocfs2console
Configure OC2FS
In RHEL/Centos the main configuration file is located in /etc/sysconfig/o2cb
However in Debian based Linux it is located........