These errors are usually caused by the lack mysql client dev files
If using mariadb install this:
apt-get install libmariadbclient-dev
If using mysql install this:
apt-get install libmysqlclient-dev........
Install exiftool:
apt install exiftool
Remove the metadata from "thefile.pdf":
exiftool -all= thefile.pdf
Warning: [minor] ExifTool PDF edits are reversible. Deleted tags may be recovered! - thefile.pdf
1 image files updated
Metadata, in the context of PDFs, refers to a set of data that describes and gives informat........
Are you getting this error in CentOS 8 when trying to use yum to install a package?
Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist
What we need to do is not use the automatic mirror list and manually set the base URL
Solution
sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS*
sed -i 's%#baseurl=http://mirror.centos.org%baseurl=........
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.........
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........
Many people may not be aware that you can turn commodity hardware into a Mikrotik OS and there are various options which is "CHR" (Cloud Hosted Router) which is a VMimage meant for Virtualization only (seriously, I've tried to dd the image to a physical server and it just crashed as it does not contain any drivers for physical).
One note as well if you are trying to do a baremetal install you may get an error "Error Loading Operating System" or........
A very common use case is that you don't want to waste time using a video editor that requires you to open it up and manually import the video clip and audio clip, then manually delete the old audio track and import the video and new audio. That's too much work and time since we don't want to go through the hassle.
ffmpeg is our solution, all we have to do is specify 3 variables and we're done!
-i Windows2019-Server-Noaudio.mp4 is our in........
This seems to happen on most if not all Nvidia cards but the good news is that if you are using any of the Linux drivers and have the nvidia-settings tool installed it is just a simple command.
Solution:
nvidia-settings --assign CurrentMetaMode="nvidia-auto-select +0+0 { ForceFullCompositionPipeline = On }"
Enter the above command in your terminal and the screentearing will be fixed which is like enabling Tear Free on AMD cards.&........
http://vault.centos.org/5.9/os/i386/repodata/filelists.xml.gz: [Errno -1] Metadata file does not match checksum
yum clean all
yum makecache
yum update........
apt install software-properties-common
add-apt-repository ppa:deadsnakes/ppa
apt update
apt install python3-pip
apt install python3.7 curl gnupg python3.7-dev git
ln -s /usr/bin/python3.7 /usr/bin/python3
pip3 install numpy keras_preprocessing
curl https://bazel.build/bazel-release.pub.gpg | sudo apt-key add -
echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel........
mdadm --create /dev/md0 --level 1 --raid-devices 2 /dev/sdb1 missing --metadata=0.90
mdadm: super0.90 cannot open /dev/sdb1: Device or resource busy
mdadm: /dev/sdb1 is not suitable for this array.
mdadm: create aborted
Sometimes running "partprobe" can fix this. Other times it requires a reboot.
One other manual thing that can be done is the following to fix it (if dm is using and blocking it):........
yum -y install wget unzip
wget https://download.nextcloud.com/server/releases/nextcloud-18.0.2.zip
unzip nextcloud-18.0.2.zip
yum -y install php php-mysqlnd php-json php-zip php-dom php-xml php-libxml php-mbstring php-gd mysql mysql-server
Last metadata expiration check: 0:58:02 ago on Fri 13 Mar 2020 02:12:49 PM EDT.
Dependencies resolved.
===================================================================........
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........
Downloading and compiling from source to get the latest version of Asterisk is really simple with this guide.
apt install gcc make g++ libedit-dev uuid-dev libjansson-dev apt install libxml2-dev sqlite3 libsqlite3-dev
wget http://downloads.asterisk.org/pub/telephony/asterisk/asterisk-16-current.tar.gz
tar -zxvf asterisk-16-current.tar.gz
cd asterisk-16.6.2/
./configure
If you get this error change y........
python3 testserver.com-car-scraping.py html.txt
Traceback (most recent call last):
File "testserver.com-car-scraping.py", line 5, in
import mysql.connector
ImportError: No module named 'mysql'
For some reason it won't install properly even though I have the mysql client on this machine installed too.
Solution:
You need the mys........
Do you hate how Centos 7 defaults to allocating most of your valuable space to /home even though it is a production server?
Here is a quick guide on how to take back that space live, while online (of course make sure you have backups just in case something goes wrong!):
First we will reduce our home dir by 100G:
lvreduce -L -100G /dev/mapper/centos-home
WARNING: Reducing active and open logical volume to ........
Before getting into the output here is my typical experience with SMART, there is what I call a "bad disk" with pending and uncorrectable sectors that cannot be reallocated.
It has caused a kernel panic and system crash repeatedly as we can see from the logs.
But SMART says it has "PASSED" its self assessment. SMART is still useful to me but it is more about looking at Current_Pending_Sector.
Any time I have had anything but 0 for that attribute it........
initiator = client
target = server
These are the first concepts you should understand which is that in iscsi essentially the "initiator" is the client and the "target" is the server.
iSCSI is derived from the old fashioned SCSI that us oldtimers grew to love. The "i" stands for Internet and the SCSI stands for "Small Computers Systems Interface" (SCSI).
iSCSI Target (Server)Setup
targetcli is the pac........
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........
Server Side Config
1.) First install nfs-utils
yum -y install nfs-utils
2.) Configure nfs share
Create a directory for your NFS share
mkdir /datastore
Create your NFS share in /etc/exports
echo "/datastore 10.220.101.0/24(rw,sync,no_root_squash)" >> /etc/exports
systemctl restart nfs........
#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........
When things go wrong your video is basically unplayable or the first video plays fine and then freezes when moving on to the next. Generally if both videos weren't produced with the exact 100% same settings you will have issues. You can try the basic concat but it often won't work right.
Solution for me:
My example uses 3 videos in total so "n=3" and a=1 to include audio.
ffmpeg -threads 12 -i file1.mp4 -........
#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 ........
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........
Finally after ages I found the solution which is on many pages on the net but not obvious and should have been standard or more common info!
Instant Solution:
Type this into the terminal (unfortunately the driver config menu doesn't have the option as itis hidden):
nvidia-settings --assign CurrentMetaMode="nvidia-auto-select +0+0 { ForceCompositionPipeline = On }"
Make permanent
Cli........
Ihave a tar and when extracting it changes /root to a uid and gid of the source server which is bad especially for /root!
You can get around this by extracting as follows:
Add the -o switch which means "--no-same-owner"
tar -o -zxvf sometar.tar.gz........
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).........
In short the solution is just to use vgremove for the actual /dev/mapper device:
vgremove /dev/mapper/backups-backuplv
box mnt # mdadm --manage /dev/md8 --stop
mdadm: Cannot get exclusive access to /dev/md8:Perhaps a running process, mounted filesystem or active volume group?
box mnt # lv
lvchange lvconvert lvcreate l........
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........
It is already known this is not possible
mdadm --create /dev/md3 --level 10 --layout=f2 --raid-devices=2 /dev/sdc1 /dev/sdd1
mdadm: /dev/sdc1 appears to be part of a raid array:
level=raid10 devices=2 ctime=Sat Dec 24 18:44:29 2016
mdadm: /dev/sdd1 appears to be part of a raid array:
level=raid10 devices=2 ctime=Sat Dec 24 18:44:29 2016
Continue creating ar........
md127 issue, it should be /dev/md3 per mdadm.conf
Any time something is mounted as md127 it almost always means there is no entry for this mdadm array in the mdadm.conf in initramfs (which is separate from your actual /etc/mdadm.conf).
cat /etc/mdadm.conf
ARRAY /dev/md3 metadata=1.2 UUID=b6722845:381cc94e:7a2c5b5f:8e3b7c4f
The reason for this is something strange, most Linux OS's bizarrely always keep their own copy of /etc/mdadm.con........
This happened while an mdadm array was syncing, all access from writing a new blank file to opening a small .txt file was very slow:
[222117.312078] kjournald starting. Commit interval 5 seconds
[222117.685060] EXT3-fs (md0): using internal journal
[222117.685096] EXT3-fs (md0): mounted filesystem with ordered data mode
[222122.376847] kjournald starting. Commit interval 5 seconds
[222122.602825] EXT3-fs (md2): using internal jour........
There are a few ways of doing this and all basically involve using the reverse proxy or "ProxyPass" feature of Apache to accomplish it.
1.) Create a normal vhost and simply symlink the root directory of the site you want to mirror.
Eg. originalsite.com and newsite.com
/vhosts/originalsite.com/httpdocs
You would symlink like this:
ln -s /vhosts/originalsite.com/httpdocs vhosts/originalsite.com/........
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........
Iwas surprised to see that Linux Mint at the latest 17.2 version still has NO mdadm installer option, and worse the installer will not be able to create a proper booting environment even when you do install it.
How to setup mdadm in Linux mint LiveCD
sudo su
apt-get install mdadm
# partition as you need and then create your mdadm devices
# create your SWAP md0
mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /d........
sudo apt-get install zoneminder
[sudo] password for one:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libuser-perl python-evince kdebase-apps kwrite unixodbc
libgnomeprint2.2-data python-soappy vgabios python-metacity hddtemp
python-mediaprof........
mdadm --create /dev/md1 --level 10 --raid-devices=2 /dev/sdb2 /dev/sdc2 --layout=f2 --metadata=0.90
Note that layout=f2 or layout=n2 is very important as without it you'll get a complaint like this:
mdadm --create /dev/md0 --level 10 --raid-devices /dev/sdb1 /dev/sdc1 missing missing
mdadm: invalid number of raid devices: /dev/sdb1
It is basically more like a prop........
It is as simple as using the "-k" option for:
-k, --keep-old-files don't replace existing files when extracting
--keep-newer-files don't replace existing files that are newer than
thei........
Error: Cannot retrieve metalink for repository: epel. Please verify its path and try again
You have to upgrade the ca-certs for epel but need to disable it before that can happen.
yum upgrade ca-certificates --disablerepo=epel........
I messed up the bootloader by accident on a standard Centos 6.3 install because I turned the /dev/vda1 boot partition into an mdadm raid 1. This was all done correctly aside from one point Ididn't realize was an issue metadata=00.90 is the only thing that will allow you to boot (otherwise grub won't work and you won't boot).
So the next step is rescue mode from a CD right? The problem you will find is that grub does not detect your hard drives, this is Ibelieve is be........
drbd 8.3 hard drive failure recovery
drbdadm attach r0
DRBD module version: 8.3.10
userland version: 8.3.8
you should upgrade your drbd tools!
0: Failure: (119) No valid meta-data signature found.
==> Use 'drbdadm create-md res' to initialize meta-data area. ........
This is what fixed it:
[root@box13 ~]# dd if=/dev/zero of=/dev/md160 bs=512 count=500
Basically you need to wipe out more than just the 512 byte partition table so 512 bytes * 500 is more than enough to make DRBD happy and think the partition is now empty.
The reason this happens is because it gets confused when there is a previous partition with data on the device you are using.
root@box13 ~]# d........
# 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........
mdadm --manage /dev/md1 --add /dev/sdb1
mdadm: metadata format 00.90 unknown, ignored.
mdadm: metadata format 00.90 unknown, ignored.
mdadm: metadata format 00.90 unknown, ignored.
mdadm: /dev/sdb1 not large enough to join array
md1's first primary member /dev/sda3 has 57394 cylinders while the /dev/sdb1 has 57393 (1 less cylinder) which is why it won't work.
fdisk -l /dev/sda3
Disk /dev/sda3: 47........
Neither the blkid or the UUID internal to mdadm work to automount for some reason in Debian
partprobe doesn't work but was a good suggestion from: http://pato.dudits.net/2008/11/03/special-device-uuidxxxxxxxxxxxxxxxx-does-not-exist-especially-with-lvm
mount: special device /dev/disk/by-uuid/431b9b96-29e8f298-e89bd504-7065bddd does not exist
mdadm -D /dev/md_d12
mdadm: metadata format 00.90 unknown, ignored.
/dev/md_d12:
&nb........
For years I've always built cheap systems believing that there is little difference in more expensive components when it comes to reliability and quality, I generally believe this still except for Power Supplies.
I've always bought cheap cases with nice sounding 350-550W stock/cheap/crap power supplies and haven't had any issues for the most part until recently.
One such case is an NGEAR case with a 550W Optimax power supply, I always read that these supplies don't produce the........
fdisk -lu VPS.img
last_lba(): I don't know how to handle files with mode 81ed
You must set cylinders.
You can do this from the extra functions menu.
Disk VPS.img: 0 MB, 0 bytes
255 heads, 63 sectors/track, 0 cylinders, total 0 sectors
Units = sectors of 1 * 512 = 512 bytes
Device Boot Start End ........
It's weird because I have a nearly identical box and setup and I can update the ovzkernel-PAE* just fine but on this box it doesn't work.
I only get this error with the openvz.repo and not others such as Centos-Base.repo
With my other server it works normally:
================
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package ovzkernel-PAE.i686 0:2.6.18-238.12.1.el5.0........
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........
mdadm: metadata format 00.90 unknown, ignored.
This happens with various versions of older mdadm such as mdadm - v2.6.7.1 - 15th October 2008
It is all because an extra 0 in 00.90 in /etc/mdadm/mdadm.conf that it doesn't like (it doesn't seem to cause any problem except that message though):
Solution - Edit your /etc/mdadm/mdadm.conf and change 00.90 to 0.90 in your arrays:
ARRAY /dev/md3 level=raid1 num-devices=2 metadata=0.90 UUID=f41a4644:6b2a05f........
I've only used it on Centos, soI thought I'd make a quick Debian guide:
Install the DRBD Package
apt-get install drbd8-utils
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libswfdec-0.8-0
Use 'apt-get autoremove' to remove them.
The following........
yum exits in the middle
The problem is this VPS seems to be an OpenVZ template from HyperVM. The only way to make it work was to disable i386 packages since this was an x64 kernel. That shouldn't be necessary but it was the only way to make yum stop quitting after the first package or two. I couldn't find any issue by checking the logs either.
echo y|yum install vim-minimal telnet expect jwhois net-tools slocate iptables elinks gawk
L........
http://apt.sw.be/redhat/el5/en/i386/test/repodata/repomd.xml: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: rpmforge-testing. Please verify its path and try again
Notice it is complaining about "rpmforge-testing", just disable it for now:
Solution is to edit the repo:
vi /etc/yum.repos.d/rpmforge-testing.repo........
This has stumped me a few times because I keep forgetting that Centos 5.5 comes with a default iptables configuration that ends up blocking DRBD traffic,I tried all the normal things and couldn't understand why I couldn't make my normal DRBD config work. So if you have WFConnection problems and have tried the normal "mailing list" fixes, check your firewall status first!
Both Nodes Say the Following:
version: 8.3.8 (api:88/prot........
Create New RAID 1 Array:
First setup your partitions (make sure they are exactly the same size)
In my example I have sda3 and sdb3 which are 500GB in size.
mdadm --create /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3
mdadm: array /dev/md2 started.
Check Status Of The Array
*Note I already have other arrays md0 and md1.
You can see below that md2 is syn........
This is a great way to reduce MySQL code/mistakes/annoyance when doing things, take for example this statement:
INSERT IGNORE INTO sometable(CatName) VALUES("someitem");
Notice the "IGNORE", that is what does the magic.
Normally if the entry "someitem" existed you'd get an error message back such as "Duplicate entry for whatever". What I have normally done in PHP or whatever language is manually coded or made a........
Why would you want to downgrade the superblock? Old mdadm verisons like mdadm 2.5.6 only use the 0.90 superblock/metadata and new versions use 1,1.0,1.1 and 1.2 superblocks by default.
There are some annoying caveats with this, first of all the new superblocks (later than 0.90) CANNOT be read by GRUB, so you won't even be able to install GRUB. Even worse, old versions of mdadm CANNOT automatically detect arrays even if they were created with a new version of mdadm with th........
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........
I successfully created a single RAID 1 partition which includes /boot inside it and my root directory through the Debian installer. It said GRUB installed successfully but when I try booting the OS it seems GRUB can't read anything.
When trying to boot from GRUB
GRUB Loading stage 1.5.
GRUB loading, please wait...
Error 2
I get "Error 2" when trying to boot Debian. I also notice from a LiveCD that........
mdadm --assemble --scan
mdadm: /dev/md/diaghost05102010:2 has been started with 2 drives.
mdadm: /dev/md/diaghost05102010:1 has been started with 2 drives.
mdadm: /dev/md/diaghost05102010:0 has been started with 2 drives.
-bash-3.1# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid6] [raid5] [raid4] [multipath]
md125 : active raid1 sda1[0] sdb1[1]
14658185 blocks super 1.2........
I decided on using yum to help me decide even though I normaly use proftpd I decided to see what else I could find.
yum search ftp
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* rpmforge: ftp-stud.fht-esslingen.de
* base: mirrors.netdna.com
* updates: updates.interworx.info
* addons: yum.singlehop.com
* extras: mirrors.netdna.com
rpmforge........
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'........