[DRBD-user] DRBD Verify Log Message Out Of Sync Blocks Units

Melanie Desaive melanie.desaive at medneo.de
Fri Dec 18 11:35:43 CET 2015

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


Hi all,

we are at the moment experiencing irregular out-of-sync blocks on our 
highly loaded system with the nightly drbd verify jobs.

Disconnect/connect does swiftly put the devices back into a correct state.

Still I would like to investigate the issue and find out what files are 
concerned by the out of sync blocks.

Is it possible to translate the information about the start of the out 
of sync area from the log into ext4 filesystem blocks (4 KiB)?
Is it maybe simply "(sectors=512 Byte) / (ext4 block size=4096 Byte)"?

... block drbd7: Out of sync: start=22378360, size=8 (sectors)
... block drbd7: Out of sync: start=49621128, size=8 (sectors)
... block drbd7: Out of sync: start=49866632, size=8 (sectors)
... block drbd7: Out of sync: start=53905280, size=8 (sectors)
... block drbd7: Out of sync: start=53913616, size=8 (sectors)
... block drbd7: Out of sync: start=56035192, size=8 (sectors)
... block drbd7: Out of sync: start=56134280, size=8 (sectors)
... block drbd7: Out of sync: start=56238448, size=8 (sectors)

When calculating with a ratio of 512/4096 = 1/8 debugfs returned, that 
all out of sync blocks are unused for the case I just investigated. This 
would be the answer I mostly appreciate. ;)

Looking forward for an answer, even if to correct my assumptions.

Greetings,

Melanie



-- 
________________________________________

medneo GmbH
Melanie Desaive

Reinhardtstr. 23-27 | 10117 Berlin

+49 (30) 814501-644

melanie.desaive at medneo.de



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