> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Phil Harman > > Milkowski and Neil Perrin's zil synchronicity [PSARC/2010/108] changes > with sync=disabled, when the changes work their way into an available > > The fact that people run unsafe systems seemingly without complaint for > years assumes that they know silent data corruption when they > see^H^H^Hhear it ... which, of course, they didn't ... because it is > silent ... or having encountered corrupted data, that they have the > faintest idea where it came from. In my day to day work I still find > many people that have been (apparently) very lucky.
Running with sync disabled, or ZIL disabled, you could call "unsafe" if you want to use a generalization and a stereotype. Just like people say "writeback" is unsafe. If you apply a little more intelligence, you'll know, it's safe in some conditions, and not in other conditions. Like ... If you have a BBU, you can use your writeback safely. And if you're not sharing stuff across the network, you're guaranteed the disabled ZIL is safe. But even when you are sharing stuff across the network, the disabled ZIL can still be safe under the following conditions: If you are only doing file sharing (NFS, CIFS) and you are willing to reboot/remount from all your clients after an ungraceful shutdown of your server, then it's safe to run with ZIL disabled. If you're unsure, then adding SSD nonvolatile log device, as people have said, is the way to go. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
