> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of David Blasingame Oracle > > Keep pool space under 80% utilization to maintain pool performance.
For what it's worth, the same is true for any other filesystem too. What really matters is the availability of suitably large sized unused sections of the hard drive. The larger the total space in your storage, the higher the percentage of used can be, while maintaining enough unused space to perform reasonably well. The more sequential your IO operations are, the less fragmentation you'll experience, and the less a problem there will be. If your workload is highly random, with a mixture of large & small operations, with lots of snapshots being created and destroyed all the time, then you'll be fragmenting the drive quite a lot and experience this more. The 80% or 90% thing is just a rule of thumb. But you positively DON'T want to hit 100% full. I've had this happen and been required to power cycle and remove things in single user mode in order to bring it back up. It's not as if 100% full is certain to cause a problem... I can look up details if someone wants to know... There is a specific condition that only occurs sometimes when 100% full, which essentially makes the system unusable. But there is one specific thing, isn't there? Where ZFS will choose to use a different algorithm for something, when pool usage exceeds some threshold. Right? What is that? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
