[CentOS] drbd strategy

Mon Jun 2 11:45:57 UTC 2008
Johnny Hughes <johnny at centos.org>

sbeam wrote:
> Thanks guys for the info. I understand that the secondary machine needs a /var 
> too while in standby, and since it can't also mount it as part of the DRBD 
> array, then it has to be a vanilla partition on both machines. Thanks for 
> clearing that up.
> 
> On Saturday 31 May 2008 09:28, Filipe Brandenburger wrote:
>> You would be better off by using a DRBD partition for "/var/lib/mysql"
>> and leaving the rest of "/var" out of DRBD.
> 
> But DRBD only replicates entire physical devices right? So I would have to 
> re-partition... if so I can't do that.
> 

DRBD replicates partitions (does not have to be a separate physical 
device) ... the normal method is to create a new partition ... copy all 
the stuff to that partition that you want to fail over and sym link it 
back to its normal locations.

There is even a program called drbdlinks to automatically change the 
symlinks from normal when the drbd partition is in secondary mode (so 
you can easily do updates on your normal locations ... but the symlinks 
shift to the drbd partition when if becomes primary):

http://www.tummy.com/Community/software/drbdlinks/

> But we could move mySQL files to /home or something as well. Not pretty but it 
> should work.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 252 bytes
Desc: OpenPGP digital signature
URL: <http://lists.centos.org/pipermail/centos/attachments/20080602/424ef536/attachment-0005.sig>