• Linux Debian Mint Ubuntu Bridge br0 gets random IP


    This can break things easily in remove environments where it was normally easy to convert a normal eth0 to a bridge under br0, and that bridge would normally have the same MAC address by default, which is desirable for most situations. In Debian 11 this is different for some reason now. https://unix.stackexchange.com/questions/681013/bridge-gets-random-mac-........
  • How to access a disk with bad superblock Linux Ubuntu Debian Redhat CentOS ext3 ext4


    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........
  • Linux how to get list of all timezones on system Ubuntu


    find /usr/share/zoneinfo/|sed s#"/usr/share/zoneinfo/"##g|grep "/"|grep -v posix|grep -v ^"Etc/"|grep -v ^right|grep -v ^"SystemV" Africa/Addis_Ababa Africa/Abidjan Africa/Blantyre Africa/Lusaka Africa/Casablanca Africa/Libreville Africa/Asmara Africa/Bujumbura Africa/Dakar Africa/Lagos Africa/Malabo Africa/Harare Africa/Kigali........
  • How To Upgrade Debian 8,9,10 to Debian 12 Bookworm


    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://........
  • RHEL 8 CentOS 8, Alma Linux 8, Rocky Linux 8 System Not Booting with RAID or on other servers/computers Solution for dracut and initramfs missing kernel modules


    This seems to have changed for RHEL 8 where a normal dracut to update your initramfs creates a system that only boots for the running kernel. For example if you have Kernel 5 and then chroot into a RHEL 8 variant which uses kernel 4.18, and run dracut, it seems that by default the system will be unbootable. It is also the case that if you move your RAID array or drives to another server that it will be unbootable, because dracut seems to only include modules needed for the curre........
  • debootstrap how to install Ubuntu, Mint, Debian install


    In this example we install debian 10 with --variant=minbase which gives us a minimal/tiny install. Don't use variant if you want the full size install. mkdir /tmp/deb10files debootstrap --variant=minbase buster /tmp/deb10files/ Did you get an error? debootstrap --variant=minbase buster /home/theuser/VMs/deb10files/ You'll get this error if you make a directory in your home........
  • Linux grub not using UUID for the root device instead it uses /dev/sda1 or other device name solution


    You can read lots of posts about this issue but there is not much information about why this is the case or how grub determines the root= device name. Some even suggest modifying grub.cfg manually which is a disaster as the next kernel update will cause grub to revert back to the device name. For most people this won't be an issue but those using template system, automated deployments and working in embedded may run into this issue with custom embedded and created minimal kernel........
  • CentOS 7 / 8 cannot boot with with mdadm RAID array solution


    This article about migrating to a CentOS 7 /8 RAID mdadm array has a lot of info but I wanted to focus specifically on what newer versions of CentOS 7 require to boot mdadm and what changes are necessary on CentOS 7.8+ CentOS 7 / 8 mdadm RAID booting requirements This assumes you are chrooting into an existing install or using it to get a new deployment ready. However, these steps can........
  • GlusterFS HowTo Tutorial For Distributed Storage in Docker, Kubernetes, LXC, KVM, Proxmox


    This can be used on almost anything, since Gluster is a userspace tool, based on FUSE. This means that all Gluster appears as to any application is just a directory. Applications don't need specific support for Gluster, so long as you can tell the application to use a certain directory for storage. One application can be for redundant and scaled storage, including for within Docker and Kubernetes, LXC, Proxmox, OpenStack, etc or just your image/web/video files or even da........
  • 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........
  • Linux how to compile binary with static sharedobjects embedded instead of dynamic to use on multi-distributions and avoid glibc compatiblity issues


    One simple flag to configure will create a makefile that statically links all the shared objects and embeds them instead the binary execute. This means as long as you have the same architecture that things should run. Eg. if you have an old version of Debian with a different version of glibc, then this will solve that problem. ./configure LDFLAGS="-static" To test that it is really statically linked run ldd: ldd src/wget........
  • Virtualbox Error Cannot register the hard disk because a hard disk with UUID already exists solution


    Cannot register the hard disk '/some/path/windows-marking.vdi' {f54def00-2252-43f5-9178-0998636cad61} because a hard disk '/other-path/windows-marking.vdi' with UUID {f54def00-2252-43f5-9178-0998636cad61} already exists. Result Code: NS_ERROR_INVALID_ARG (0x80070057) Component: VirtualBoxWrap Interface: IVirtualBox {0169423f-46b4-cde9-91af-1e9d5b6cd945} Callee RC: VBOX_E_OBJECT_NOT_FOUND (0x80BB0001)........
  • mdadm how to stop a check


    Is a mdadm check on your trusty software RAID array happening at the worst time and slowing down your server or NAS? cat /proc/mdstat Personalities : [raid1] [raid10] md127 : active raid10 sdb4[0] sda4[1] 897500672 blocks super 1.2 2 near-copies [2/2] [UU] [==========>..........] check = 50.4% (452485504/897500672) finish=15500.3min speed=478K/sec ........
  • Linux How To Change NIC Name to eth0 instead of enps33 or enp0s25


    Most newer distros inexplicably cause your NIC to have what Icall "random" non-standard name conventions because of systemd. This is a big problem for many people and especially those running servers. Imagine that you have a static IPconfigured for ens33 but then the hard disk is moved to a newer system, the NIC could be anything from ens33 to enp0s1, meaning that manual intervention is required to go and update the NIC config file (eg. /etc/network/interfa........
  • OpenVZ vs LXC DIR mode poor security in LXC


    It is unfortunate that LXC's dir mode is completely insecure and allows way too much information from the host to be seen. I wonder if there will eventually be a way to break into the host filesystem or other container's storage? OpenVZ better security: [root@ev ~]# cat /proc/mdstat cat: /proc/mdstat: No such file or directory /dev/simfs 843G 740G 61G........
  • Convert and install to LUKS Encrypted Drive Ubuntu 18.04 19.10 Linux Mint and Debian Based Linux


    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.)........
  • CentOS 8 how to convert to a bootable mdadm RAID software array


    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 how to connect using a SOCKS 5 proxy with nc and proxycommand


    This is not about using ssh as a proxy, but rather, using a proxy when you are SSHing to another host and using ProxyCommand (where we normally use nc as our proxy tool). In newer versions of nc the syntax has changed to the following: ssh -o ProxyCommand="nc -x 127.0.0.1:1234" %h %p user@host The format must be like above in newer nc versions. Just be sure to change the 1234 to the port of your SOC........
  • How To Install Asterisk 16 17 on Debian Ubuntu Linux


    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........
  • How To Boot Cisco CUCM UCSInstall 8.6, 10, 11 and 12 on KVM/Proxmox


    The key thing is that you must use a "machine"id of "pc-1.3" or it will say your hardware is not supported. Additionally you MUST use a virtio disk or you will get a ks_pre.sh error as soon as the install starts (a look at logs will show it can't find a disk). This is funny because even though the OS finds the disk and an fdisk -l shows it, it looks like the script looks for a /dev/vda device (virtio) and nothing else, so if you didn't use Virtio as you........
  • VirtualBox How To Add iSCSI Storage using VBoxManage


    #to show all VBoxManage list vms #show ONLY running vms VBoxManage list runningvms VBoxManage storageattach test --storagectl "SATA" --port 0 --device 0 --type hdd --medium iscsi --server 192.168.1.91 --target "iqn.2018-12.local.abcrandom.target:sdb" --initiator "iqn.1982-01.ca.bla.tld:abc123" --t........
  • linux mint image convert menu option missing solution


    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........
  • Linux Mint Black Screen after boot no graphics solution


    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........
  • Mozilla Firefox Address Bar History Not Working places.sqlite corruption solution database repair


    Here is the only solution Ifound that works in Firefox: *Note you could basically just copy all of the commands in bold (the rest just shows the output) Install sqlite3 sqlite3 places.sqlite sqlite> .clone places.sqlite-fixed moz_places... done moz_historyvisits... done moz_inputhistory..........
  • Ubuntu/Debian/Linux won't boot and drops to Busybox shell after cloning HDD with dd


    I don't recall having this issue in the distant past but nowadays at least Debian seems to be very picky about this. I used dd to copy one hard drive to another and tried booting it. Everything seemed fine with grub working but each time it would drop to the busybox shell. There is no particular error so this is misleading. Normally the first things you would check are to make sure your fstab is correct (that the UUID is correct)and that you've updated grub.&........
  • Migrate Centos 7 from Single HDD to mdadm RAID 10 array:


    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........
  • How to change reserved blocks in Linux partition


    user@box:~$ sudo tune2fs -l /dev/md99 [sudo] password for user: tune2fs 1.42.9 (4-Feb-2014) Filesystem volume name: Last mounted on: /mnt/md50 Filesystem UUID: 976a8655-2619-4587-878c-dab07f7b7652 Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Fi........
  • Migrating from Linux Mint 17.2 mdadm RAID array to a new one (because I upgraded to larger drives).


    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).........
  • mdadm and lvm how to completely disable and remove vg/pv/lv


    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........
  • DRBD Split-brain solution


    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........
  • mdadm change wrong device name md127 fix and solution in Linux


    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........
  • Vbox Cannot register the hard disk


    Cannot register the hard disk '/media/Debian8.vdi' {d01efabc-aacf-4614-b29c} because a hard disk '/home/VirtualBox VMs/Debian/Debian8.vdi' with UUID {d01efabc-aacf-4614-b29} already exists. This is what happens if you move the VDI to another location. The easiest way is to delete/remove the machine from VBOX and then reimport it from the new location.........
  • Centos 6 how to guide convert LVM non-RAID into mdadm 1/10 RAID array live without reinstalling


    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........
  • openvz yum problem Centos 6.5 cannot find file on mirror:


    #solution Edit /etc/yum.repos.d/openvz.repo For the first two entries comment out #mirrorlist and uncomment #baseurl and then it worked openvz yum problem Centos 6.5 cannot find file on mirror: yum update Loaded plugins: fastestmirror Determining fastest mirrors * openvz-kernel-rhel6: mirrors.ustc.edu.cn * openvz-utils: mirrors.ustc.edu.cn base ........
  • Dell CS24-NV7 lspci dmidecode info


    0000:00:00.0 RAM memory: NVIDIA Corporation MCP55 Memory Controller (rev a2) 0000:00:01.0 ISA bridge: NVIDIA Corporation MCP55 LPC Bridge (rev a3) 0000:00:01.1 SMBus: NVIDIA Corporation MCP55 SMBus (rev a3) 0000:00:02.0 USB controller: NVIDIA Corporation MCP55 USB Controller (rev a1) 0000:00:02.1 USB controller: NVIDIA Corporation MCP55 USB Controller (rev a2) 0000:00:05.0 IDE interface: NVIDIA Corporation MCP55 SATA Controller (rev a3) 0000:00:05.1 I........
  • 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........
  • drbd won't sync 8.3.13 on OpenVZ kernel


    I used the matching 8.3.13 utilities and it didn't work but strangely the newer 8.3.16 which makes DRBD complain works just fine. GIT-hash: 83ca112086600faacab2f157bc5a9324f7bd7f77 build by root@sighted, 2012-10-09 12:47:51  0: cs:SyncSource ro:Secondary/Primary ds:UpToDate/Inconsistent A r-----     ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:5236960   &am........
  • LVM Tutorial how to create a Physical Volume (PV), Volume Group (vg), and a Logical Volume (LV) within it


    # 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........
  • What a hdd hard drive and mdadm RAID array failure looks like in Linux


    [3805108.257042] sd 0:0:0:0: [sda] 1953525168 512-byte hardware sectors: (1.00 TB/931 GiB) [3805108.257052] sd 0:0:0:0: [sda] Write Protect is off [3805108.257054] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 [3805108.257066] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [3805108.257083] sd 0:0:0:0: [sda] 1953525168 512-byte hardware sectors: (1.00 TB/931 GiB) [3805108.257090] sd 0:0:0:0: [sda] Write Protect is off........
  • Migrate Linux Mint OS from one drive to another


    mount -o bind /proc /sda2/proc mount -o bind /dev/ /sda2/dev mount -o bind /sys /sda2/sys chroot /sda2 mint / # mount -o bind /proc /sda2/proc mint / # mount -o bind /dev/ /sda2/dev mint / # mount -o bind /sys /sda2/sys mint / # chroot /sda2 mint / # cd ~ mint ~ # ls Desktop mint ~ # cd / mint / # ls bin Desktop dev-temp home&nb........
  • mdadm how to add additional RAID 1 drives


    This is a great way to upgrade your RAID array or move it/copy it to a new set of hard drives. Eg. you have a current RAID 1 array on older/slower drives. Just add at least 1 of the new drives to the array, update grub/install it and then boot into it. Then you have a transparent data migration that is fully synchronized. mdadm --grow /dev/md126 --raid-devices 3 md127 : active raid1 sdc1........
  • Dell FS12-NV7 2U Server Information and Guide


    I've got one of these for testing projects from work at home and got more than I bargained for with the time I've spent on it due to the storage handing/Perc 6/i cards. My particular model came with the following: 2U Rack Mount Server with Rails 2xOpteron 2373 EE (Quad Core, there is a 6-core version that can be found at times) 16GB RAM 2 x 250GB Seagate SATA 2 x Dell Perc 6/i (horrible and a nightmare to work........
  • How to use the Linux mail command to attach a file


    The key here is to use the "uuencode" command but note that we specify the file name twice (this must be done at least on Centos or it won\'t work). The first file.zip is the actual file we want to send. The second file.zip i........
  • mdadm enable bitmap to speed up rebuilds


    Have you ever unplugged the wrong drive and then had to rebuild the entire array? It may not be a big deal in some ways but it does make your system vulnerable until the rebuild is done. Many distros often enable the "bitmap" feature and this basically keeps track of what parts need to be resynced in the case of a temporary removal of a drive from the array, this way it only needs to sync what has changed. To enable bitmap to speed up rebuilds and sync........
  • mdadm create RAID 1 array example


    mdadm --create /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3 cat /proc/mdstat Personalities : [raid1] md2 : active raid1 sdb3[1] sda3[0] 1363020736 blocks super 1.2 [2/2] [UU] [=>...................] resync = 8.3% (113597440/1363020736) finish=276.2min speed=75366K/sec ........
  • Centos how to upgrade from PHP 5.2 to 5.3 without downtime


    This may sound silly but there will be conflicts/issues with the default Centos repository so you have to use a third party like remi (I prefer not to do this but it's the only option unless you migrate your sites/data to another server or can stand some downtime-not an option IMHOon a production server). You may need to upgrade to PHP5.3 to run Joomla or many other reasons. Your host needs to use PHP 5.2.4 or higher to run this version of Jo........
  • Debian UUID not working


    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........
  • KVM QEMU and Xen how to mount disk images off-line and access data


    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 ........
  • Virtualbox How To Clone VM/Container VDI file


    You can't just do a straight copy of the VDI image of your virtual machine because there is a unique UUID, wellI believe you can and then you can create a new UUID manually (at least you could with VMWARE) but to keep it clean just use this method: VBoxManage clonevdi /path/to/your.vdi outputname.vdi 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100% That's all there is to it, just wait for it copy and you can th........
  • mdadm/md-check how to check array integrity without rebuilding


    This doesn't seem to be widely known (maybe it's in some documentation that none of us read though)but there's an easy way to check the integrity of any mdadm array: sudo echo check > /sys/block/md0/md/sync_action -bash: /sys/block/md0/md/sync_action: Permission denied sudo will never work, this only works as root since echo is not actually a binary/command. It is built-into bash. /sys/devices/virtu........
  • md: data-check of RAID array md3


    This really made me nervous but notice the mdstat says "check". This is because in Ubuntu there is a scheduled mdadm cronscript that runs everyday on Sunday at 00:57 that checks your entire array. This is a good way because it prevents gradual but unnoticed data corruption which Inever thought of. As long as the check completes properly you have peace of mind knowing that your data integretiy is assured and that your hard drives are functioning properly (I'........
  • mdadm: metadata format 00.90 unknown, ignored.


    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........
  • mdadm RAID 1 adventures


    I separated the 2 drives in the RAID 1 array. 1 is the old one /dev/sda and is out of date, while the separated other one /dev/sdc was in another drive and mounted and used with more data (updated). I wonder how mdadm will handle this: usb-storage: device scan complete md: md127 stopped. md: bind md: md127: raid array is not clean -- starting background reconstruction raid1: raid set md127 active with 1 out of 2 m........
  • Ubuntu 10.04/GRUB2 mdadm won't boot


    Moving to RAID was a pain. What you have to do is the following from an existing install: Install mdadm Create your mdadm RAID 1 array on your spare hard drive. Start it with the missing disk. rsync the entire contents of your current / to the md partition. Here's a good way of doing it: rsync -Pha --exclude=/proc/* --exclude=/sys/* --exclude=/mnt/* /. /mnt/md2........
  • mdadm Linux Software RAID QuickStart Guide


    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........
  • VirtualBox Error Failed to start the virtual machine Centos 5.5 Mirror. Medium '/home/testuser/.VirtualBox/HardDisks/Centos 5.5 Mirror.vdi' is not accessible. UUID {a1a9fad7-0402-4867-b8f3-39fb49454bc5} of the medium '/home/testuser/.VirtualBox/HardD


    Virtualbox Error I tried to copy a .vdi of one container to use in another one, basically to clone instead of having to install the OS again. Failed to start the virtual machine Centos 5.5 Mirror. Medium '/home/testuser/.VirtualBox/HardDisks/Centos 5.5 Mirror.vdi' is not accessible. UUID {a1a9fad7-0402-4867-b8f3-39fb49454bc5} of the medium '/home/testuser/.VirtualBox/HardDisks/Centos 5.5 Mirror.vdi' does not match the value {4945a0e8-0ed5-4736-9088-bcaf........
  • md: kicking non-fresh sda1 from array! - fix/solution


    md: Autodetecting RAID arrays. md: autorun ... md: considering sdb1 ... md: adding sdb1 ... md: adding sda1 ... md: created md0 md: bind md: bind md: running: md: kicking non-fresh sda1 from array! md: unbind md: export_rdev(sda1) raid1: raid set md0 active with 1 out of 2 mirrors The md0 raid kicked sda1 ou........
  • mdadm "auto-read-only" Linux Software RAID solution


    If you have the "(auto-read-only)" beside an arrayI have no idea why that happens but it is easy to fix. Just run "mdadm --readwrite /dev/md1" (rename md0 to the device with the problem and it will begin to resync. md1 : active (auto-read-only) raid1 sdb2[0] sda2[1] 19534976 blocks [2/2] [UU] resync=PENDING ........
  • Why does mdadm have two sets of UUID's?


    Which one does the OS care about? blkid says the UUID is "787f1fa4-b010-4d77-a010-795b42884f56" while md insists its UUID is "4d96dd3b:deb5d555:7adb93cb:ce9182d9" When in doubt, do we assume the OS takes the one from blkid? /dev/md0: UUID="787f1fa4-b010-4d77-a010-795b42884f56" TYPE="ext3" [root@localhost ~]# mdadm -D /dev/md0 /dev/md0: Version : 0.90 &........
  • Centos 5.5 RAID 1 boot issue


    I installed 5.5 with a 300GB RAID 1 partition (boot is also on this partition). It booted up fine the first few times until after I used a Live CD and accessed the array, and it became named /dev/md127 for some reason. Now whenI boot into CentOS I get a kernel panic and different errors, once I got "invalid superblock", even though the array is fine (it didn't happen again, probably because I was sure to dismount and stop the mdadm array properly). Here's what........
  • mdadm Linux Software RAID auto-detect and assemble RAID Array


    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........
  • Convert HDD/Hard Drive Partition(s) into non-RAID into RAID 1 using existing data without data loss and without reformatting.


    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........
  • Linux EXT3 16GB-17GB maximum filesize issue solved/how to fix


    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/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........
  • Basic Port Listing


    Basic Port ListingHopefully someone finds this useful or at least interesting. http://www.sans.org/top20/#u9 Name Port Protocol Description Small services ........
  • Latest Articles

  • How To Add Windows 7 8 10 11 to GRUB Boot List Dual Booting
  • How to configure OpenDKIM on Linux with Postfix and setup bind zonefile
  • Debian Ubuntu 10/11/12 Linux how to get tftpd-hpa server setup tutorial
  • efibootmgr: option requires an argument -- 'd' efibootmgr version 15 grub-install.real: error: efibootmgr failed to register the boot entry: Operation not permitted.
  • Apache Error Won't start SSL Cert Issue Solution Unable to configure verify locations for client authentication SSL Library Error: 151441510 error:0906D066:PEM routines:PEM_read_bio:bad end line SSL Library Error: 185090057 error:0B084009:x509 certif
  • Linux Debian Mint Ubuntu Bridge br0 gets random IP
  • redis requirements
  • How to kill a docker swarm
  • docker swarm silly issues
  • isc-dhcp-server dhcpd how to get longer lease
  • nvidia cannot resume from sleep Comm: nvidia-sleep.sh Tainted: Linux Ubuntu Mint Debian
  • zfs and LUKS how to recover in Linux
  • [error] (28)No space left on device: Cannot create SSLMutex Apache Solution Linux CentOS Ubuntu Debian Mint
  • Save money on bandwidth by disabling reflective rpc queries in Linux CentOS RHEL Ubuntu Debian
  • How to access a disk with bad superblock Linux Ubuntu Debian Redhat CentOS ext3 ext4
  • ImageMagick error convert solution - convert-im6.q16: cache resources exhausted
  • PTY allocation request failed on channel 0 solution
  • docker error not supported as upperdir failed to start daemon: error initializing graphdriver: driver not supported
  • Migrated Linux Ubuntu Mint not starting services due to broken /var/run and dbus - Failed to connect to bus: No such file or directory solution
  • qemu-system-x86_64: Initialization of device ide-hd failed: Failed to get