On 31 May, 2011 - Khushil Dep sent me these 4,5K bytes: > The adage that I adhere to with ZFS features is "just because you can > doesn't mean you should!". I would suspect that with that many > filesystems the normal zfs-tools would also take an inordinate length > of time to complete their operations - scale according to size.
I've done a not too scientific test on reboot times for Solaris 10 vs 11 with regard to many filesystems... Quad Xeon machines with single raid10 and one boot environment. Using more be's with LU in sol10 will make the situation even worse, as it's LU that's taking time (re)mounting all filesystems over and over and over and over again. http://www8.cs.umu.se/~stric/tmp/zfs-many.png As the picture shows, don't try 10000 filesystems with nfs on sol10. Creating more filesystems gets slower and slower the more you have as well. > Generally snapshots are quick operations but 10,000 such operations > would I believe take enough to time to complete as to present > operational issues - breaking these into sets would alleviate some? > Perhaps if you are starting to run into many thousands of filesystems > you would need to re-examin your rationale in creating so many. On a different setup, we have about 750 datasets where we would like to use a single recursive snapshot, but when doing that all file access will be frozen for varying amounts of time (sometimes half an hour or way more). Splitting it up into ~30 subsets, doing recursive snapshots over those instead has decreased the total snapshot time greatly and cut the "frozen time" down to single digit seconds instead of minutes or hours. > My 2c. YMMV. > > -- > Khush > > On Tuesday, 31 May 2011 at 11:08, Gertjan Oude Lohuis wrote: > > > "Filesystem are cheap" is one of ZFS's mottos. I'm wondering how far > > this goes. Does anyone have experience with having more than 10.000 ZFS > > filesystems? I know that mounting this many filesystems during boot > > while take considerable time. Are there any other disadvantages that I > > should be aware of? Are zfs-tools still usable, like 'zfs list', 'zfs > > get/set'. > > Would I run into any problems when snapshots are taken (almost) > > simultaneously from multiple filesystems at once? > > > > Regards, > > Gertjan Oude Lohuis > > _______________________________________________ > > zfs-discuss mailing list > > zfs-discuss@opensolaris.org (mailto:zfs-discuss@opensolaris.org) > > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss /Tomas -- Tomas Ögren, st...@acc.umu.se, http://www.acc.umu.se/~stric/ |- Student at Computing Science, University of Umeå `- Sysadmin at {cs,acc}.umu.se _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
