On Tue, Jun 18, 2013 at 02:38:19PM +0200, Kurt Bauer wrote: > > > Da Chun schrieb: > > > > Thanks for sharing! Kurt. > > > > Yes. I have read the article you mentioned. But I also read another > > one: http://www.hastexo.com/resources/hints-and-kinks/turning-ceph-rbd-images-san-storage-devices. > > It uses LIO, which is the current standard Linux kernel SCSI target. > > That has a major disadvantage, which is, that you have to use the kernel > rbd module, which is not feature equivalent to ceph userland code, at > least in kernel-versions which are shipped with recent distributions. > Yes, that is why I like that some Ceph developers added rbd to tgt. It's just a lot easier to do upgrades. I don't expect it to be much slower either. I believe I read somewhere that LIO in the kernel has it's limits. Specifically the number of threads...? But I could be wrong. The disadvantage of tgt is the clustering support does not work (yet ?). > > > > There is another doc in the ceph > > site: http://ceph.com/w/index.php?title=ISCSI&redirect=no > > <http://ceph.com/w/index.php?title=ISCSI&redirect=no> > Quite outdated I think, last update nearly 3 years ago, I don't > understand what the box in the middle should depict. > > > I don't quite understand how the multi path works here. Are the two > > ISCSI targets on the same system or two different ones? > > Has anybody tried this already? > > > Leen has illustrated that quite well. > > > ------------------ Original ------------------ > > *From: * "Kurt Bauer"<kurt.bauer@xxxxxxxxxxxx>; > > *Date: * Tue, Jun 18, 2013 03:52 PM > > *To: * "Da Chun"<ngugc@xxxxxx>; > > *Cc: * "ceph-users"<ceph-users@xxxxxxxxxxxxxx>; > > *Subject: * Re: ceph iscsi questions > > > > Hi, > > > > > > Da Chun schrieb: > >> Hi List, > >> > >> I want to deploy a ceph cluster with latest cuttlefish, and export it > >> with iscsi interface to my applications. > >> Some questions here: > >> 1. Which Linux distro and release would you recommend? I used Ubuntu > >> 13.04 for testing purpose before. > > For the ceph-cluster or the "iSCSI-GW"? We use Ubuntu 12.04 LTS for > > the cluster and the iSCSI-GW, but tested Debian wheezy as iSCSI-GW > > too. Both work flawless. > >> 2. Which iscsi target is better? LIO, SCST, or others? > > Have you read > > http://ceph.com/dev-notes/adding-support-for-rbd-to-stgt/ ? That's > > what we do and it works without problems so far. > > > >> 3. The system for the iscsi target will be a single point of failure. > >> How to eliminate it and make good use of ceph's nature of distribution? > > That's a question we asked aourselves too. In theory one can set up 2 > > iSCSI-GW and use multipath but what does that do to the cluster? Will > > smth. break if 2 iSCSI targets use the same rbd image in the cluster? > > Even if I use failover-mode only? > > > > Has someone already tried this and is willing to share their knowledge? > > > > Best regards, > > Kurt > > > >> > >> Thanks! > >> _______________________________________________ > >> ceph-users mailing list > >> ceph-users@xxxxxxxxxxxxxx > >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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