I would like to combine my harddisks to a nested raid (raid0 and raid5).
My System files are on a separate drive (sda).
I have six disks:
#System files /dev/sda #Raid0 (/dev/md0) all are 750G /dev/sdb /dev/sdc /dev/sdd #Raid5 (/dev/md1) /dev/md0 /dev/sde (2T) /dev/sdf (2T)
I have run following commands:
mdadm --create /dev/md0 -n3 -l0 /dev/sdb /dev/sdc /dev/sdd mdadm --create /dev/md1 -n3 -l5 /dev/md0 /dev/sdc /dev/sdd mdadm --examine --scan > /etc/mdadm.conf cat /proc/mdstat
shows /dev/md1 in rebuilding state.
after a reboot /dev/md1 is in inactive state and has only /dev/sde and /dev/sdf as members
As a workaround to this problem I created two additional raid0 (/dev/md0 is the same as above):
mdadm --create /dev/md1 -n1 -l0 /dev/sde --force mdadm --create /dev/md2 -n1 -l0 /dev/sdf --force
and then combined them with md0:
mdadm --create /dev/md3 -n3 -l5 /dev/md0 /dev/md1 /dev/md2
This seems to work fine. After reboots the rebuild process continues and everything is in state "active".
Is there a better way to solve this? It looks to me like a very ugly workaround.
Sorry for my bad English :-)
Thank you for helping me with this problem.
Last edited by absinthe (2011-01-13 20:58:33)
I am currently having the same issue: I have three physical disks: two of 80 GB in RAID 0 (/dev/md/Data_RAID) and one 500 GB disk with a 160 GB partition (/dev/sde1) which I am using together for another RAID 1 array (/dev/md/Data).
Although I do not have a solution to your problem, I would like to say that you have a workaround, at least.
/dev/sdc1 80 GB
/dev/sdd1 80 GB
Also, I think you made a typo error: I think you meant /sde and /sdf in the level 5 array, instead of /sdc and /sdd.
mdadm --create /dev/md0 -n3 -l0 /dev/sdb /dev/sdc /dev/sdd mdadm --create /dev/md1 -n3 -l5 /dev/md0 /dev/sdc /dev/sdd [...]
mdadm --create /dev/md0 -n3 -l0 /dev/sdb /dev/sdc /dev/sdd mdadm --create /dev/md1 -n3 -l5 /dev/md0 /dev/sde /dev/sdf