On Sun, Apr 6, 2008 at 2:47 PM, Jamie Wilkinson <[EMAIL PROTECTED]> wrote:
> This one time, at band camp, Crossfire wrote: > > Dave Kempe wrote: > >> Crossfire wrote: > >>> I want to be able to set it up so /home (and maybe other filesystems) > >>> are replicated from one to the other, in both directions, in real > >>> time so they can run in an all-hot redundant cluster. > >>> > >>> The environment should be mostly read-oriented, so I can live with > >>> write-latent solutions as long as they handle the race/collision > >>> gracefully (preferably by actually detecting and reporting it if they > >>> can't avoid it). > >>> > >> isn't this just a description of a network filesytem... say NFS? > > > > No. Network Filesystems still have a distinct single storage location. > > If that storage is taken offline, clients can only error or hang. > > > > With a hot real-time replicated filesystem, all involved nodes would > > have a full local copy at all times and would be able to continue > > operation. > > I agreed with your earlier decision about not using drbd because you > wouldn't be able to write from multiple nodes to the filesystem; all the > slaves would have to be mounted read-only. However if you wanted to get Can you provide links which support this? I've been using DRBD for a few months now (just in stand-by mode, but been following the forums and docs during that time) and all indications are that: 1. You CAN'T mount a non-cluster-aware file system even read-only on the secondary node since the primary will change FS-structs under the feet of the read-only node and cause it to crash (because non-cluster-aware filesystems assume that they are the only ones who touch that partition). 2. You CAN mount read-write on multiple nodes if you use one of the cluster-aware filesystems (GFS and OCFS are regularly mentioned, but if you find any other cluster-aware file system then it sounds like it will work too). Ref: http://www.linux-ha.org/DRBD/FAQ#head-2cad8caa095cfb6e2935261cb595390c742ebd86 > fancy you could still use drbd (which is a great fit for all your other > requirements) on a multi-node fileserver, and do some nifty failover using > IP takeover. > > Or if you're trying to share the local disk of a lot of nodes, then what > if > you used DRBD on them all to replicate the block device, and run a NFS > server on the nodes thremselves? Yes you'd get a lot of network traffic > between them, but it'd work, no? :) Have you tried this suggestions? From all I read about DRBD this will cause all secondary nodes to crash. Cheers, --Amos -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html