[DRBD-user] new drbd install - filesystem size

Leroy van Logchem leroy.vanlogchem at wldelft.nl
Wed Jan 3 10:02:21 CET 2007

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

> 3) I edit drbd.conf and set the size of each mirrored partition to be 132M 
> smaller than the actual size of the partition. This is larger than the 
> required 128M, but just to be sure.
> 4) I start drbd.
> 5) I create a filesystem on the drbd devices with a command that looks 
> something like this: mkfs.ext3 /dev/drbd0
> I wanted to be sure that 3) was the correct way to leave space at the end of 
> the partition on a new filesystem. The quick-start guide talks about 
> shrinking an existing filesystem, but I think that it doesn't apply here. Is 
> that correct?
I would create a dedicated meta-disk and configure it like this:
---/etc/drbd.conf sniplet---
  on host.fqdn {
        device        /dev/drbd0;
        disk            /dev/sda4;
        address      a.b.c.d:someport;
        meta-disk   /dev/sda3 [0];
Make sure that you create the meta-data partition large enough (fdisk 
+128M is just a little too small).
Drbd will complain so you can't go wrong. The advantage of this setup is:
-you can mount the device under drbd (ofcourse *only* do this as last 
resort) and only contains a normal filesystem.
-clearing the meta-disk is easy (again only in case of trouble)

I never had any trouble with drbd but this setup is robust imho.

More information about the drbd-user mailing list