[DRBD-user] disk size

[Lars Ellenberg]

/ 2004-02-11 22:29:58 +0100
\ Andreas Huck:
> Hi,
> 
> On Friday 06 February 2004 04:40, Anshul Gupta wrote:
> > Hi Everyone,
> >
> > I am in process of setting up HA cluster and using DRBD for filesystem
> > replication. I have created partition /dev/hda2 of 20 GB, currently
> > using just 8GB. It takes approx 30 minutes to sync the entire partiton
> > for the first time.
> >
> > Can I change the disk-size parameter to say 10G (in drbd.conf) so that
> > sync time is reduced and later when I need more space, increase it?
> > Will there be any problem if I proceed this way?
> 
> the disk-size in drbd.conf just needs to be larger or equal to the size
> of your filesystem on top of it. So if you use reiserfs, for example, you
> may do the following:
> 
> 1) stop heartbeat on both nodes (/proc/drbd shows both as secondary)
> 2) drbdsetup /dev/nb0 primary  (on node A) 
> 2) resize_reiserfs -s 10G /dev/nb0 (on node A) 
>    Beware: shrinking is experimental. If its a new system, just
>    create a 10G filesystem (and a filesystem which allows to enlarge it).
> 3) drbdsetup /dev/nb0 secondary  
> 4) Comment out the original (or final) disk-size and set it to 10G in
>    your /etc/drbd.conf (hm, don't know whether it understands the G,
>    just copy-n-past $((10*1024*1024)) from your bash :-)

uhm. please do 4) before  2),
and make sure that the new device size shows up in drbdsetup /dev/nbX show !
yes, it understands G.

> 5) scp your new drbd.conf to your node B. 
> 6) (re)start of drbd on either node will make it primary and start a
>    full sync.