[DRBD-user] Uncatchable DRBD out-of-sync issue

Felix Frank ff at mpexnet.de
Mon Mar 25 10:30:48 CET 2013

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

You forget to CC the list...

On 03/25/2013 10:22 AM, Stanislav German-Evtushenko wrote:
>> there is a certain risk of data not reaching the hard disk soundly.
> It seems so but what is a way to catch the reason?

Really not much you can do. Not sure if ZFS is viable and helpful.

>> What's your hard disk stack?
> RAID 1+0 on both nodes.

Not knowing what controllers Dell put into that r710, replacing them is
probably out of the question anyway.
They *could* be to blame. You could try disabling the write cache.
Prepare for a somewhat limited performance.

Speaking of performance, that al_extents value is a mite small.

>> If you have the freedom, there are some things to try, e.g.
>> - not use ethernet bonding
> I can try but it will decrease bandwidth from 200MiB/s to 100MiB/s and
> disable redundancy.
>> - not use dual-primary
> I can't because I need online migration (I know it's dangerous to do
> migration now, because data can be not synced properly)
>> - use a smaller partition
> Why?
Just throwing some bones. If one of these help (doubtful, but not
impossible), then you know where to debug further.

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