Fran Varas Blog

The history of an incredibly curious guy

a RAID6 made of pendrives

mdadm --verbose --create /dev/md0 --level=6 --raid-devices=5 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 /dev/sdg1

mdadm: layout defaults to left-symmetric mdadm: chunk size defaults to 512K mdadm: layout defaults to left-symmetric mdadm: layout defaults to left-symmetric mdadm: /dev/sdc1 appears to contain an ext2fs file system size=2000896K mtime=Thu Jan 1 01:00:00 1970 mdadm: layout defaults to left-symmetric mdadm: /dev/sdd1 appears to contain an ext2fs file system size=1970176K mtime=Thu Jan 1 01:00:00 1970 mdadm: layout defaults to left-symmetric mdadm: /dev/sde1 appears to contain an ext2fs file system size=1972224K mtime=Fri Apr 29 13:38:05 2011 mdadm: layout defaults to left-symmetric mdadm: /dev/sdf1 appears to contain an ext2fs file system size=2000896K mtime=Thu Jan 1 01:00:00 1970 mdadm: layout defaults to left-symmetric mdadm: /dev/sdg1 appears to contain an ext2fs file system size=1970176K mtime=Thu Jan 1 01:00:00 1970 mdadm: size set to 1968640K mdadm: largest drive (/dev/sdc1) exceeds size (1968640K) by more than 1% Continue creating array? y mdadm: Defaulting to version 1.2 metadata mdadm: array /dev/md0 started.

mdadm --detail /dev/md0

/dev/md0: Version : 1.2 Creation Time : Fri Apr 29 13:50:32 2011 Raid Level : raid6 Array Size : 5905920 (5.63 GiB 6.05 GB) Used Dev Size : 1968640 (1922.82 MiB 2015.89 MB) Raid Devices : 5 Total Devices : 5 Persistence : Superblock is persistent

Update Time : Fri Apr 29 13:51:27 2011
      State : clean, resyncing

Active Devices : 5 Working Devices : 5 Failed Devices : 0 Spare Devices : 0

     Layout : left-symmetric
 Chunk Size : 512K

Rebuild Status : 8% complete

       Name : fvaras-fixe:0  (local to host fvaras-fixe)
       UUID : f2d6513e:84c70f15:be858661:686bbaa9
     Events : 1

Number   Major   Minor   RaidDevice State
   0       8       33        0      active sync   /dev/sdc1
   1       8       49        1      active sync   /dev/sdd1
   2       8       65        2      active sync   /dev/sde1
   3       8       81        3      active sync   /dev/sdf1
   4       8       97        4      active sync   /dev/sdg1

then, take a look to this post

By the way, I'm not even trying to fine tune this redundant array on inexpenside disks ;)