telling mdadm to use spare drive.

From: Janek Kozicki
Date: Sun Nov 04 2007 - 09:21:10 EST


Hi,

I finished copying all data from old disc hdc to my shiny new
RAID5 array (/dev/hda3 /dev/sda3 missing). Next step is to create a
partition on hdc and add it to the array. And so I did this:

# mdadm --add /dev/md1 /dev/hdc3

But then I had a problem - the /dev/hdc3 was a spare, it didn't
resync automatically:

# mdadm -D /dev/md1
[....]
Number Major Minor RaidDevice State
0 3 3 0 active sync /dev/hda3
1 8 3 1 active sync /dev/sda3
2 0 0 2 removed

3 22 3 - spare /dev/hdc3


I wanted to tell mdadm to use the spare device, and I wasn't sure how
to do this, so I tried following:

# mdadm --stop /dev/md1
# mdadm --assemble --update=resync /dev/md1 /dev/hda3 /dev/sda3 /dev/hdc3

Now, 'mdadm -D /dev/md1' says:
[...]
Number Major Minor RaidDevice State
0 3 3 0 active sync /dev/hda3
1 8 3 1 active sync /dev/sda3
3 22 3 2 spare rebuilding /dev/hdc3


I'm writing here just because I want to be sure that I added this new
device correctly, I don't want to make any stupid mistake here...

# cat /proc/mdstat

md1 : active raid5 hda3[0] hdc3[3] sda3[1]
966807296 blocks super 1.1 level 5, 128k chunk, algorithm 2 [3/2] [UU_]
[=>...................] recovery = 6.2% (30068096/483403648) finish=254.9min speed=29639K/sec
bitmap: 8/8 pages [32KB], 32768KB chunk

Was there a better way to do this, is it OK?

--
Janek Kozicki |
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