[DRBD-user] Digest integrity check failed

Florian Haas florian at hastexo.com
Thu Nov 3 22:32:48 CET 2011

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

On 2011-11-03 22:15, Nick Morrison wrote:
> On 3 Nov 2011, at 09:25, Florian Haas wrote:
>> Read the bullet list. Then start troubleshooting your network stack.
>> When you get "Digest integrity check FAILED" errors, you have every
>> reason _not_ to be sure the network is OK.
> I'm now finding myself a cable to connect these hosts directly.

That may or may not solve your issue; the original motivation for the
data integrity feature was to catch issues with NICs, not cables.

> Next question: can I now depend on my data being the same over both disks?  Should I run an online verify?  Or is the fact that it caught the problem and stopped enough to ensure integrity?

Let's put it this way: it's highly, highly unlikely that borked data
ended up on your disk, but you can run a verify anyway. Now, just so you
don't freak out needlessly when you do find out-of-sync sectors: verify
you still run into false positives, as explained at length here:


Have we mentioned storage replication is complicated? :)

> I would like to run a verify regularly, but I ran into a problem.  I added the verify-alg parameter to the net section of my resource, but drbdadm complains when I adjust:
>         net {  
>                 cram-hmac-alg   sha1;
>                 shared-secret   avnerunvaadsf4n4nn4b4bnb4ai4jfaoi4hf;
>                 after-sb-0pri   discard-zero-changes;
>                 after-sb-1pri   discard-secondary;
>                 data-integrity-alg      md5;
>                 verify-alg  md5;
>         }
> root at kvm-host-01:~# drbdadm adjust host1
> drbd.d/host1.res:22: Parse error: 'an option keyword' expected,
>         but got 'verify-alg'
> root at kvm-host-01:~# 
> I guess the syntax has changed.  How do I enable this in Lucid's DRBD 8.3.7?

It belongs in the "syncer" section in 8.3.x.


Hope this helps,

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