badly destroyed XFS (on LVM) - how to repair?

[Michael Monnerie]

Another strange thing:

I now started a "dd if=/dev/dm-0 of=/dev/null bs=1024k".
For the first seconds(!), it did nothing, I thought it would hang.
Then it started, but it's reading in a strange way:

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
xvdg          139378,24     0,00 15893,61    0,00 77640,82     0,00     9,77    35,96    2,26   0,06  99,88
xvda              0,00     0,00    0,00    0,00     0,00     0,00     0,00     0,00    0,00   0,00   0,00
xvde              0,00     0,00    0,00    0,00     0,00     0,00     0,00     0,00    0,00   0,00   0,00
xvdb              0,00     0,00    0,00    0,00     0,00     0,00     0,00     0,00    0,00   0,00   0,00
dm-0              0,00     0,00 155241,52    0,00 77620,76     0,00     1,00   353,51    2,28   0,01  99,88

Very many I/Os and very slow KB/s. What could cause that?
lv readahead is 1536 sectors, that's 128KB per data disk (a 7 disk RAID-5) and should be OK.

-- 
mit freundlichen Grüssen,
Michael Monnerie, Ing. BSc

it-management Internet Services: Protéger
http://proteger.at [gesprochen: Prot-e-schee]
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