Scott Dickson writes: > How does (or does) ZFS maintain sequentiality of the blocks of a file. > If I mkfile on a clean UFS, I likely will get contiguous blocks for my > file, right? A customer I talked to recently has a desire to access
you would get up to maxcontig worth of sequential block. But only inasmuch as there is a single thread in the system doing the allocating writes. When more threads compete for blocks we end up with less contiguity. With ZFS, i believe that as part of a transaction group (a big sync every 5 second) dirtied blocks of a file are reordered by offsets then sent to disk in that order. It would be interesting to see if it truly works that way but basically ZFS may reduce the randomness as part of the sync. -r > > --SCott > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
