Am 20.12.2012 15:31, schrieb Mark Nelson: > On 12/20/2012 01:08 AM, Roman Hlynovskiy wrote: >> Hello Mark, >> >> for multi-mds solutions do you refer to multi-active arch or 1 active >> and many standby arch? > > That's a good question! I know we don't really recommend multi-active > right now for production use. Not sure what our current recommendations > are for multi-standby. As far as I know it's considered to be more > stable. I'm sure Greg or Sage can chime in with a more accurate > assessment. We have been testing a lot with multi-standby, because a single MDS does not make a lot of sense in a cluster. Maybe the clue is to have only one standby, making SPOF a DPOF? Up to 0.55 with some of Yan's fixes, Ceph has been too instable whenever it came to MDS failover. As long as the same MDS has been kept active, it was quite stable. We are really hoping for 0.56 with the additional MDS fixes and also fixed kernel 3.8 code. We have been waiting to replace our existing cluster fs with CephFS for at least one and a half years, but it has never been stable enough in our setup with standby MDS and takeover, let alone multi-active. We do not want to risk a complete cluster failure. Amon Ott -- Dr. Amon Ott m-privacy GmbH Tel: +49 30 24342334 Am Köllnischen Park 1 Fax: +49 30 99296856 10179 Berlin http://www.m-privacy.de Amtsgericht Charlottenburg, HRB 84946 Geschäftsführer: Dipl.-Kfm. Holger Maczkowsky, Roman Maczkowsky GnuPG-Key-ID: 0x2DD3A649 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
