[PVE-User] drbd issues after kernel upgrade

[Flavio Stanchina]

[re-sending to the list, I answered only to Robert by mistake]

Robert Fantini wrote:
> On 01/26/2012 11:29 AM, Robert Fantini wrote:
>> we're using Proxmox 2.0.
>> since updating pve-kernel on Tuesday we've had drbd issues. the new
>> kernel is Version: 2.6.32-55+ovzfix-1 .
>>
>> Here are syslog entries:
>>
>> on Primary:
>> Jan 26 09:58:11 fbc19 kernel: block drbd0: Digest mismatch, buffer
>> modified by upper layers during write: 801263472s +4096
>
> This issue was solved by removing 'data-integrity-alg' from
> /etc/drbd.conf .

Ah. This means that your system is corrupting data in transit. Either a 
driver/firmware problem in the network card or bad cabling/bad switches.

> from http://www.drbd.org/users-guide/re-drbdconf.html : 'We suggest to
> use the data-integrity-alg only during a pre-production phase due to its
> CPU costs. Further we suggest to do online verify runs regularly e.g.
> once a month during a low load period.'

Yes, data-integrity-alg is doing its job, if you disable it those errors 
will go unnoticed. Reread what you quoted carefully and you'll see what 
I mean.

See: http://www.drbd.org/users-guide/s-integrity-check.html

-- 
Flavio Stanchina
Informatica e Servizi
Trento - Italy