[DRBD-user] Mystery with online verify and Out of sync sectors.

Florian Haas florian.haas at linbit.com
Tue Jun 17 10:08:11 CEST 2008

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

Dimitrij Hilt wrote:
 >> Right. And now can you do
>> dd if=<dev> skip=<start> bs=512 count=<size> iflag=direct | openssl md5
>> ... where <dev> is your backing device, <start> is the first out-of-sync
>> sector as reported in the kernel log, and <size> is the number of
>> out-of-sync sectors?
> I did it allready.
>> Please do that on both nodes, for a handful (say 5 or so) of out-of-sync
>> areas reported in your syslog.
>> If those MD5 sums match, then these are apparently false positives and
>> we'll have to look into what's causing them.
>> If, however, they do not match, replace "openssl md5" with "xxd" in the
>> command above, and try to interpret those hex dumps. Are they completely
>> different, do they not match at all, or are you seeing just one or two
>> seemingly random differences?
> Yes, i saw differences. These sectors was not false positives.

OK. Do you have some of those xxd dumps still lying around? Can you post
one or two pairs of those?

> At the moment the problem is away. I did:
> change meta-disc to internal
> disable data-integrity-alg

Did you try these changes one at a time, or both at once?


: Florian G. Haas
: LINBIT Information Technologies GmbH
: Vivenotgasse 48, A-1120 Vienna, Austria

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