28 мая 2014 г. 15:51:36 CEST, Dan Swartzendruber <[email protected]> пишет: >(merging comments to Saso and Jim) > >I don't think I mentioned my environment - if not, my apologies. This >is >a SOHO/Lab setup, so things like zeusram are non-starters. The basic >network infrastructure is gigabit, so iSCSI ZIL would suck badly, I >suspect. As far as over-provisioning the 840PRO, I have it sliced for >16GB. Once it's been running for awhile, I will re-run the disk >benchmark. I understand the 840PRO doesn't have a supercap - this was >basically just a performance analysis to see how it stacks up compared >to >sync=disabled and on-pool ZIL. If I go this route, I will need to look >for a decent/affordable unit with supercap. One other test I can try >is >with a 15K 76GB SAS 2.5-inch drive I salvaged from a dead server. It >should have about 1/2 the latency of a 7200rpm sata drive, and if so >would >get me up to about 40MB/sec, which is still not good, but better than >on-pool ZIL. I'll find out later. I have googled a fair amount and >there >seems to be 'work in progress' for TRIM support for ZoL and illumos, >but >no real indication I could find as to when either might support it. > > > >_______________________________________________ >OmniOS-discuss mailing list >[email protected] >http://lists.omniti.com/mailman/listinfo/omnios-discuss
Actually, i think that if you have the hdd dedicated for zil, then you only write sequentially to it, so the head hovers where it should be. Track-to-track seek time can be discarded and the worst latency is a single rotation. With much enough data (liky sync=always) you have a 15krpm streaming write... some 200MBps? //Jim -- Typos courtesy of K-9 Mail on my Samsung Android _______________________________________________ OmniOS-discuss mailing list [email protected] http://lists.omniti.com/mailman/listinfo/omnios-discuss
