On Tue, Jun 20, 2006 at 11:17:42AM -0700, Jonathan Adams wrote: > On Tue, Jun 20, 2006 at 09:32:58AM -0700, Richard Elling wrote: > > Flash is (can be) a bit more sophisticated. The problem is that they > > have a limited write endurance -- typically spec'ed at 100k writes to > > any single bit. The good flash drives use block relocation, spares, and > > write spreading to avoid write hot spots. For many file systems, the > > place to worry is the block(s) containing your metadata. ZFS inherently > > spreads and mirrors its metadata, so it should be more appropriate for > > flash devices than FAT or UFS. > > What about the UberBlock? It's written each time a transaction group > commits.
Right. But we rotate the uberblock over 128 positions in the device label. This helps with write-leveling. Furthermore, a lot of flash devices are starting to incorporate write-leveling in HW, since a lot of software just doesn't deal with it. --Bill _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
