• mdadm: add new device failed for /dev/sdb4 as 3: Invalid argument solution


    mdadm --manage /dev/md125 -a /dev/sdb4 mdadm: add new device failed for /dev/sdb4 as 3: Invalid argument Dec 19 01:23:48 storageboxtest kernel: [ 2328.854491] md: sdb4 does not have a valid v1.2 superblock, not importing! Dec 19 01:23:48 storageboxtest kernel: [ 2328.854499] md: md_import_device returned -22 #zero the superblock and try again! mdadm --zero-superblock /dev/sdb4 mdadm --ma........
  • How To Turn Any .iso file into a bootable USB drive


    This works for almost all ISO's Ifind (at least Linux based): sudo dd if=CentOS-6.9-x86_64-minimal.iso of=/dev/sdg bs=20M 20+1 records in 20+1 records out 427819008 bytes (428 MB) copied, 118.233 s, 3.6 MB/s Of course change the .iso filename above and the /dev/sdg to your desired USB drive!........
  • USB 3.0 PCI x1 Card Review VIA VL805 on Linux Review and Experience


    This is a VIA made VL805 USB 3.0 Chipset with 4-ports and MOLEX powered. First of all this unit was cheap at about only 9 USD with fast shipping. My biggest concern was if this was a quality unit and would it really give you full USB 3.0 speeds (some people reported with similar cards that for some weird r........
  • ADATA SU800 256GB 3D NAND Flash SSD Test & Review


    I keep reading these drives are slower, but they are cheap and still SSDand work very fast for my needs. As you can see the sequential read is 481-491MB/s, if I put them in MDADM RAID10 mode (normal RAID1) they should give me well over 900MB/s and with redundancy and being very cheap for what they offer. [1232206.315622] scsi 8:0:1:0: Direct-Access ATA ADATA SU800&........
  • mdadm mirrored RAID1 performance using RAID10 -f2 (Far Layout) is the solution


    The only way I've found in mdadm to make 2 drives perform like a proper RAID 1 (eg. the read speed should be 2x that of a single drive) is to use the --layout=f2 (far 2). mdadm raid10 performance issues. Be very aware that mdadm seems to default to layout=n2 (which means near). In this scenario it means it is like mdadm RAID 1 performance (you get maximum read speeds of a single drive). dd if=/dev/md126 of=/dev/null bs=1M cou........
  • cp ignore symlink and copy the actual file


    This can be very tricky, say you are doing development on a file that is symlinked. Doing a "cp dev.file dev.file-bk" won't do what you expect, it just links back to the same file so you haven't copied or backed anything up. You need the "-H" switch to copy the actual file that is referenced by the symlink: cp -Hdev.file dev.file-bk........
  • drbd won't create device if previous partition is on it Command 'drbdmeta 0 v08 /dev/md160 internal create-md' terminated with exit code 40


    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........
  • Dell Perc 6/i SATA benchmarks without battery


    The results are not bad, the Hitachi performs the same as it does in a SATA2 motherboard. However, the 2TB is much different, on a similar 2TB Toshiba I get about 198MB/s on a different motherboard vs the 2TB Hitachi which should produce similar results. This Dell Perc 6/i is on a PCI x8 riser card and is connected to a 12-port backplane. Adapter #0 Enclosure Device ID: 32 Slot Number: 0 Enclosure position: N/A De........
  • Linux copy file and not just the symlink, How-To/Solution


    cp -L index.php index.php-2013-08-21 The -L switch is what you need because it's a huge issue if you think you've copied a file for backup purposes but it really just creates a symlink to the original file.........
  • MySQL HowTo Copy Duplicate a Table for backup purposes


    This is a great way to test and experiment without risking your current table, or to make a backup of your current table to avoid corruption or dataloss due to malicious activity eg. deletion etc.. There are two steps and two commands 1.)Copy Table Structure "cars_backup" is the new table and it will be a copy of the table called "cars"........
  • Samsung Galaxy Note I717M Canadian Version, Root and Unlock


    I chose this because I heard a lot of stories about scams and that many providers I contacted said they can't unlock the Canadian I717s (one said "my Bell server" is down). This method worked perfectly on my Bell I717M and should work for all I717 in Canada, I was able to insert a foreign SIMcard. This will work abroad too but remember entering CWM mode is different for I717's in other countries (at least theUS). Step 1 - Root + CWM........
  • How to Encode all VOBs from a DVD/Bluray VIDEO_TS folder into an XVID


    In my case I already copied the VIDEO_TS folder to my hard drive. Here is the command for mencoder: mencoder -dvd-device "myvideobackup/VIDEO_TS" dvd:// -ovc xvid -oac mp3lame -lameopts cbr:br=128 -xvidencopts pass=2:bitrate=-700000 -o myvideobackup.avi Replace "-dvd-device myvideobackup/VIDEO_TS" with the location of your backup files or the /dev device of your DVD drive. The -o myvideobackup.avi is of course the name o........
  • How To Test If Your Hard Drive Is Good/Signs of dying hard drive


    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........
  • Thunderbird/MBOX to IMAP/Maildir migration done easy with mb2md


    Convert MBOX Mail files into Maildir using Linux *You need perl an the TimeDate module Get the free Perl script mb2md from the project/author's site: wget http://batleth.sapienti-sat.org/projects/mb2md/mb2md-3.20.pl.gz gunzip mb2md-3.20.pl.gz #remember you need timedate or you'll get this error: ./mb2md-3.20.pl Can't locate........
  • 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........
  • Revert to GRUB 0.97/1 instead of GRUB2


    had trouble trying to revert Ubuntu 10.04 LTS from grub2, won't boot mdraid and did not even install mdadm during the installation! I have tried moving back to GRUB 0.97 backed up original /boot and then copied /boot from an old Debian install. Modified device.map and menu.lst and put the appropriate kernels and initrd for Ubuntu back in /boot I ran grub: root (hd0,1) grub> setup (hd0) Checking if "/boot/grub/stage1........
  • rsync skipping non-regular file


    skipping non-regular file "mnt/lib/udev/devices/console" skipping non-regular file "mnt/lib/udev/devices/kmem" skipping non-regular file "mnt/lib/udev/devices/loop0" skipping non-regular file "mnt/lib/udev/devices/null" skipping non-regular file "mnt/lib/udev/devices/ppp" skipping non-regular file "mnt/lib/udev/devices/net/tu Solution for skipping non-regular file You need the -D........
  • rsync my favorite/best/optimal default switches and options


    Not sure what rsync switches/options to use? rsync -PDrphogtl The short version would be: rsync -Pha I think these are really common sense options to use and probaby should be the default. Explanation of rsync switches P = display the progress D = hybrid of --specials and --devices so all special and device files will be copied as well. r = recursive (otherwise rsync won't copy files deeper than........
  • 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........
  • 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........
  • SIOCSIFADDR No such device eth0 error while getting interface flags - eth0 Ethernet Device can


    Igot this after copying a VMWare image onto another machine in Debian. SIOCSIFADDR No such device eth0 error while getting interface flags The solution 1.) Find and edit the device line in persisent-net.rules note it will be prefixed with something like z25 or something else. vi /etc/udev/rules.d/z25_persistent-net.rules The easiest way is to comment anything out. If you are feeling........
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