[DRBD-user] DRBD and iSCSI

Ryan Cooley rcooley at starcalif.com
Thu Sep 9 21:41:22 CEST 2010

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

On Thu, 9 Sep 2010 14:57:55 +0200
Bart Coninckx <bart.coninckx at telenet.be> wrote:

> Maybe I might throw in a warning: I use a active/passive iSCSI server based on 
> Heartbeat and DRBD as well and it serves both blockdevices for Xen guests as 
> storage for a Novell NSS file system. After deliberately failing over (so 
> minimal disconnection time) the volume survived all the time, except for one: 
> it was corrupted. Novell technical services pointed out this could happen to 
> any filesystem since it is the equivalent of pulling the harddrive cable.

No halfway-decent filesystem should become corrupted after sudden power-loss.  There may be loss of file data that has not yet been comitted to disk, but it definitely should not become corrupted.

With Ext3/4 you may need to adjust the data= mode to something that recovers better, AND you need to be using a disk which supports barriers (eg. NOT an LVM), but integrity should be maintained.  Some others (eg. ext2) may need to have any non-battery-backed cache disabled, or other options changed to ensure metadata isn't lost.  

More information about the drbd-user mailing list