[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [Linux-cluster] IMAP server clustering ...




See www.drbd.org


What is DRBD

GIF image


DRBD is a block device which is designed to build high availability clusters. This is done by mirroring a whole block device via (a dedicated) network. You could see it as a network raid-1.


On Nov 1, 2004, at 10:59 AM, linux-cluster spam dragonhold org wrote:

On Mon, Nov 01, 2004 at 11:26:07AM -0700, Michael Gale wrote:

That makes more sense ... thanks for the info and in helping me avoid corrupted data.

Michael.


No worries - I have the best possible reason for remembering, that of personal experience.


I managed to miss that a partition was mounted on a solaris box (through veritas), and
therefore mounted it again manually (raw partition) somewhere else - the behaviour was
"interesting" until it got so bad I rebooted.


I ended up having to restore from the backup, which is why I remember it so vividly - we had
never tested the backups until then.



You've got me thinking tho. Depending on how much of the caching is done in the filesystem
layer, and how much at the block device layer, it /might/ be possible to create a cluster
aware block device, and then use a normal FS on top of it.


Anyone around know enough to tell me how possible/not that would be?

If it was possible, it should be possible to implement things like mirroring & snapshots at
that level more easily than trying to do them higher up the chain.


However, that may just be total baloney, since I've not really thought it through - one of
those "I wonder" ideas that I don't know enough about at the moment to investigate.


Graham

--
Linux-cluster mailing list
Linux-cluster redhat com
http://www.redhat.com/mailman/listinfo/linux-cluster


David B. Zafman | Hewlett-Packard Company
mailto:david zafman hp com | http://www.hp.com
"Computer Science" is no more about computers than astronomy is about telescopes - E. W. Dijkstra



[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]