On Tue, May 27, 2014 at 10:21 AM, Richard Elling > > This is getting a bit off topic but quite important as to the reason you > would want to under provision an SSD. > > I have no doubt, Richard, knows the internals of ZFS better than me. I > have however done several long running IOzone tests against Samsung 840 Pro > SSDs sliced at 10% intervals between 60% and 100%. IOzone only allocated > a small percentage of the total. It was always clear at 90% and 100% when > the total pool capacity had been written as performance would drop off, no > matter what the write size. Between each run, all the SSDs were secure > erased, re-partitioned and allowed to sit idle for 1 hour so that all > blocks were zero when starting. > > > Interesting results. Were you testing the "disk" or "disk with ZFS"? > > Disk (SSD) with ZFS. This was prior to the new metaslab allocation, so likely running again today would yield slightly different results. I'd be curious to run again using ZFS reservations instead. Maybe when I build the next ZFS SSD pool whenever that may be.
-Chip > ------------------------------------------- illumos-discuss Archives: https://www.listbox.com/member/archive/182180/=now RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be Modify Your Subscription: https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4 Powered by Listbox: http://www.listbox.com
