On Sun Sep 16, 2012 at 11:01:41 +0200, Adam Ryczkowski wrote:
> Welcome.
>
> I try to recover from linux software raid failure. I am in a process of
> recreating the superblocks based on a syslog from the system when it was
> healthy. The log speaks about 2 md devices, each based on 5 500GB
> partitions. The RAID-5 /dev/md5 is composed from /dev/sd[b-f]6 and
> RAID-6 /dev/md6 is composed from /dev/sd[b-f]5. The relevant part dmesg
> log looks like this:
>
> Questions:
> # What do the numbers on the line [ 5.979771] 4: w=1 pa=0 pr=5 m=1
> a=2 r=5 op1=0 op2=0 mean, including the first 4:?
4 is the raid device number
w=1 indicates the number of working disks found so far
pa=0 is the previous algorithm (used when reshaping)
pr=5 is the previous number of raid devices (used when reshaping)
m=1 is the maximum number of degraded disks allowed for the array to run
a=2 is the algorithm used
r=5 is the number of raid devices
op1=0 indicates that the disk is not a parity-only disk in the previous
layout (used when reshaping)
op2=0 indicates that the disk is not a parity-only disk in the current
layout
> # What do the numbers on the line [ 6.039266] --- rd:5 wd:5] mean?
rd is the number of devices in the array
wd is the number of working devices in the array
> # What do the numbers on the line [ 6.046856] disk 0, o:1, dev:sdb6 mean?
0 is the raid device number
o:1 indicates that it's operational (i.e. not marked as faulty)
dev:sdb6 indicates the kernel device name
> # Does the line [ 6.096768] created bitmap (15 pages) for device md5
> tell anything about the place, where the bitmap is located and what is
> its size?
>
It doesn't tell you anything about the place. I've no idea how the
number of pages equates to the bitmap size/bitmap chunk size though.
In the above cases, the raid device number is its position within the
array, so from 0..N-1 for an N-device array. This will indicate the
order you'll need to use when recreating the array.
HTH,
Robin
--
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( ' } | Robin Hill <robin@xxxxxxxxxxxxxxx> |
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