> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Bob Friesenhahn > > It is good to keep in mind that only small writes go to the dedicated > slog. Large writes to to main store. A succession of that many small > writes (to fill RAM/2) is highly unlikely. Also, that the zil is not > read back unless the system is improperly shut down.
Can anyone verify this? I thought the decision for small vs large sync writes to go to log vs main store was determined by zfs_immediate_write_sz and logbias. logbias was introduced in snv_122, which is zpool 18 or 19. zfs_immediate_write_sz seems to have been around forever (I see comments about it as early as 2006). Then again, I can't seem to find my zfs_immediate_write_sz, via either zpool or zfs. Can anybody say what version zpool introduced zfs_immediate_write_sz, or perhaps I'm using the wrong commands to try and see mine? zpool get all rpool | grep zfs_immediate_write_sz ; zfs get all rpool | grep zfs_immediate_write_sz I thought, if you didn't explicitly tune these, all sync writes go to ZIL before the main store. Can't seem to find any way to verify this. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
