Roy Sigurd Karlsbakk wrote:
I have read people are having problems with lengthy boot times with lots of datasets. We're planning to do extensive snapshotting on this system, so there might be close to a hundred snapshots per dataset, perhaps more. With 200 users and perhaps 10-20 shared department datasets, the number of filesystems, snapshots included, will be around 20k or more.
In my experience the boot time mainly depends on the number of datasets, not the number of snapshots. 200 datasets is fairly easy (we have >7000, but did some boot-time tuning).
Will trying such a setup be betting on help from some god, or is it doable? The box we're planning to use will have 48 gigs of memory and about 1TB L2ARC (shared with SLOG, we just use some slices for that).
Try. The main problem with having many snapshots is the time used for zfs list, because it has to scrape all the information from disk, but with having so much RAM/L2ARC that shouldn't be a problem here. Another thing to consider is the frequency with which you plan to take the snap- shots and if you want individual schedules for each dataset. Taking a snapshot is a heavy-weight operation as it terminates the current txg. Btw, what did you plan to use as L2ARC/slog? --Arne
Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 r...@karlsbakk.net http://blogg.karlsbakk.net/ -- I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et elementært imperativ for alle pedagoger å unngå eksessiv anvendelse av idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og relevante synonymer på norsk. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
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