On 02/08/09 11:50, Vincent Fox wrote: > So I have read in the ZFS Wiki: > > # The minimum size of a log device is the same as the minimum size of device > in > pool, which is 64 Mbytes. The amount of in-play data that might be stored on > a log > device is relatively small. Log blocks are freed when the log transaction > (system call) > is committed. > # The maximum size of a log device should be approximately 1/2 the size of > physical > memory because that is the maximum amount of potential in-play data that can > be stored. > For example, if a system has 16 Gbytes of physical memory, consider a maximum > log device > size of 8 Gbytes. > > What is the downside of over-large log device?
- Wasted disk space. > > Let's say I have a 3310 with 10 older 72-gig 10K RPM drives and RAIDZ2 them. > Then I throw an entire 72-gig 15K RPM drive in as slog. > > What is behind this maximum size recommendation? - Just guidance on what might be used in the most stressed environment. Personally I've never seen anything like the maximum used but it's theoretically possible. Neil. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
