On Thu, Mar 29, 2012 at 11:40 AM, Vladislav Bogdanov <bub...@hoster-ok.com> wrote: > Hi Florian, > > 29.03.2012 11:54, Florian Haas wrote: >> On Thu, Mar 29, 2012 at 10:07 AM, Vladislav Bogdanov >> <bub...@hoster-ok.com> wrote: >>> Hi Andrew, all, >>> >>> I'm continuing experiments with lustre on stacked drbd, and see >>> following problem: >> >> At the risk of going off topic, can you explain *why* you want to do >> this? If you need a distributed, replicated filesystem with >> asynchronous replication capability (the latter presumably for DR), >> why not use a Distributed-Replicated GlusterFS volume with >> geo-replication? > > I need fast POSIX fs scalable to tens of petabytes with support for > fallocate() and friends to prevent fragmentation. > > I generally agree with Linus about FUSE and userspace filesystems in > general, so that is not an option.
I generally agree with Linus and just about everyone else that filesystems shouldn't require invasive core kernel patches. But I digress. :) > Using any API except what VFS provides via syscalls+glibc is not an > option too because I need access to files from various scripted > languages including shell and directly from a web server written in C. > Having bindings for them all is a real overkill. And it all is in > userspace again. > > So I generally have choice of CEPH, Lustre, GPFS and PVFS. > > CEPH is still very alpha, so I can't rely on it, although I keep my eye > on it. > > GPFS is not an option because it is not free and produced by IBM (can't > say which of these two is more important ;) ) > > Can't remember why exactly PVFS is a no-go, their site is down right > now. Probably userspace server implementation (although some examples > like nfs server discredit idea of in-kernel servers, I still believe > this is a way to go). Ceph is 100% userspace server side, jftr. :) And it has no async replication capability at this point, which you seem to be after. > Lustre is widely deployed, predictable and stable. It fully runs in > kernel space. Although Oracle did its best to bury Lustre development, > it is actively developed by whamcloud and company. They have builds for > EL6, so I'm pretty happy with this. Lustre doesn't have any replication > built-in so I need to add it on a lower layer (no rsync, no rsync, no > rsync ;) ). DRBD suits my needs for a simple HA. > > But I also need datacenter-level HA, that's why I evaluate stacked DRBD > and tickets with booth. > > So, frankly speaking, I decided to go with Lustre not because it is so > cool (it has many-many niceties), but because all others I know do not > suit my needs at all due to various reasons. > > Hope this clarifies my point, It does. Doesn't necessarily mean I agree, but the point you're making is fine. Cheers, Florian -- Need help with High Availability? http://www.hastexo.com/now _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
