• mdadm: super0.90 cannot open /dev/sdb1: Device or resource busy mdadm: /dev/sdb1 is not suitable for this array.


    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):........
  • 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........
  • Linux Ubuntu Debian Centos How To Make a Bootable Windows 7, 8, 10, 2016, 2019 Server USB from ISO


    Use fdisk on your USB drive to create a bootable NTFS partition (in my case /dev/sdb): sudo fdisk /dev/sdb Welcome to fdisk (util-linux 2.27.1). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help): n Partition type p primary (0 primary, 0 extended, 4 free)........
  • Linux Ubuntu Debian Missing privilege separation directory: /var/run/sshd


    service sshd status ● ssh.service - OpenBSD Secure Shell server Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled) Active: failed (Result: start-limit-hit) since Wed 2019-10-02 11:07:54 EDT; 36s ago Process: 476 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=255) Oct 02 11:07:54 box systemd[1]: Failed to start OpenBSD Secure Shell server. Oct 02 11:07:54 box sys........
  • Ubuntu Debian Mint Linux SSHD OpenSSH Server Not Starting After Reboot Solution


    If you get error messages like this it is usually because /var/run/sshd does not exist. root@userbox:/# service sshd status ● ssh.service - OpenBSD Secure Shell server Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enab Active: failed (Result: start-limit-hit) since Wed 2019-04-10 02:24:44 EDT; 1 Process: 511 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=255)........
  • Linux partprobe/partx cannot access last and 4th partition


    On a test machine Iwas never able to access to a newly created 4th partiton. As we can see there are dev devices for everything but the 4th partition. The normal "partprobe" or "kpartx" or kernel being told to rescan the block device didn't help (only a reboot did). fdisk -l /dev/sda Disk /dev/sda: 750.2 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders Units........
  • ffmpeg how to watermark and concatenate in one command


    If you were in my boat you were frustrated that you had to double encode, eg. one separate encode for watermark and a separate from concat and it's not easy to figure out this with ffmpeg on your own. However it is a nice way to save time! ffmpeg -i file1.mp4 -i file2.mp4 -i file3.mp4 -i watermark.png -filter_complex "[0:v]setpts=PTS-STARTPTS[v0]; [1:v]setpts=PTS-STARTPTS[v1]; [2:v]setpts=PTS-STARTPTS[v2]; [v0][0:a][v1][1:a][v2][2:a]concat=n=3:v=1:a=1[v][aout]; [v][3:........
  • 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 ........
  • How to verify SSL SHA-1 Certificate Fingerprnit Signature of your mail/web server to avoid hijacking/man-in-the-middle attacks


    This is especially helpful if you run your own servers. If you are presented with an error message or warning that the signature has changed or does not match the IP/domain you are connecting to you always want to verify manually. So your e-mail/web client will show you an SHA-1 fingerprint like this: "Could not verify this certificate because the issuer is unkown" or other reasons such as a mismatch in IP/domain. It will also show you........
  • 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........
  • Linux How To Recover Partition Table from Kernel and Restore Centos/Debian etc..


    We've all done this at some point, you work on the wrong shell window and this was my first time making this mistake but I deleted a partition table in fdisk, recreated it and saved it with "wq" and even ran partprobe! If you haven't rebooted yet then you can still recover your partition table, otherwise you're in big trouble. Fortunately since it was a live system and in use the kernel still had to use the old table like below:........
  • 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.........
  • mdadm real example of recovery and rebuilding of the array on Centos 6


    In this example we have 2 drives in a RAID array and /dev/sdb is the one that failed. /dev/sda1 is also the /boot partition which we tell grub to install on /dev/sdb eg install root (hd0,0) /dev/sda1 on the new drive /dev/sdb (hd1) First copy the partition table from /dev/sda to /dev/sdb dd if=/dev/sda of=/dev/sdb bs=512 count=1 Run partprobe to detect the new partition table partprobe........
  • LSI MegaRAID Adventures, Guide and HowTo


    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........
  • 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........
  • mdadm how to add a device to an array after a failure


    This array is a RAID 1 and in this case 1 of the 2 drives failed (a WD drive and I've found them to be the weakest and most unreliable of any brand and are easily damaged/DOA when shipping them). mdadm --manage /dev/md0 --add /dev/sdb1 The above assumes the array you want to add to is /dev/md0 and the device we are adding is /dev/sdb1 *One thing to remember is to make sure the partition you are adding is the correct size for the array. You can also g........
  • 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........
  • Centos Solution to "Warning: Unable to open /dev/fd0 read-write (Read-only file system). /dev/fd0 has been opened read-only."


    Warning: Unable to open /dev/fd0 read-write (Read-only file system). /dev/fd0 has been opened read-only. That's a very annoying error, it's simply because Centos for some reason thinks it's wise to load the "floppy" kernel module, who has a floppy drive? I haven't seen or used a floppy for over 12 years! It's more than just annoying, if you probe the drives attached to your system, eg. with grub or partprobe, it keeps trying to locate a flopp........
  • VOIP/Asterisk/FAX Error Problems Solution NOTICE[11389]: rtp.c:1808 ast_rtp_read: Unknown RTP codec 100 received from


    NOTICE[11389]: rtp.c:1808 ast_rtp_read: Unknown RTP codec 100 received from I've found that trying several times may work, but I also read changing your Sipura VOIP adapter settings as follows helps (but it still fails for me sometimes): In adapter change the following under SIP/Advanced Codec to G711a from G711u Passthru Method from: NSE to ReINVITE FAX CED Detect Enable: Yes FAX CNG Detect........
  • mdadm: /dev/sda1 is too small: 0K - solution


    I was creating a RAID array and got this error: mdadm: /dev/sda1 is too small: 0K mdadm: create aborted Of course sda1 is not too small, both partitions sda1 and sdb1 are identical in size: Disk /dev/sda: 2000.3 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0x00000000 Device Boot Sta........
  • Linux AHCI Hotswap Tips - Remember To Reread The Partition Table WITHOUT rebooting


    From the package "parted" you can use the command "partprobe" to re-read the partition table. I really hate rebooting, and that's what Iloved to hear about AHCI motherboards, that they allow hotswap so you don't have to reboot. But that's only as good as the OS, if the OS does not reload the partition table you won't be able to do anything with that new drive you attached without rebooting. Yes, even without re-reading the partiton table Linux will........
  • Asterisk FreeBSD compile problems


    Asterisk FreeBSD compile problemsI couldn't get it to compile without using the following options at compile time: [b:b7d672ee28] make install WITHOUT_ZAPTEL=YES WITHOUT_MYSQL=YES WITHOUT_FAX=YES WITHOUT_ODBC=YES WITHOUT_H323=YES[/b:b7d672ee28]Some problems you might have with copying over your Linux config files to FreeBSD is different paths. [b:f044931f41]For example the etc path for Asterisk on BSD will now be:[/b:f044931f41] [qu........
  • Vonage & Linksys Offer Trade-In Program


    Vonage & Linksys Offer Trade-In ProgramVonage & Linksys Offer Trade-In Program Monday, June 13 @ 09:22:36 PDT Vonage is offering customers a way to get a free 802.11g router when they turn in their old one. advertising For a limited time, customers can trade-in their used router any brand, any model for a Linksys Wireless-G Router with 2 Phone Jacks for broadband telephony (WRTP54G) for free (after rebates), when they si........
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