On 2-8-2010 2:53, Richard Elling wrote: > On Jul 30, 2010, at 11:35 AM, Andrew Gabriel wrote: > > >> Just wondering if anyone has experimented with working out the best zvol >> recordsize for a zvol which is backing a zpool over iSCSI? >> > > This is an interesting question. Today, most ZFS implementations are done > directly on devices with an effective, fixed recordsize of 512 bytes. But > that > isn't very efficient and things like raidz don't quite work like you might > expect. > Next up is 4KB sectors, which is a better starting point, IMHO. > > That said, ultimately it is the size of the data to be written that dictates > the > best answer. > > Up to now i configure the recordsize of a iscsi zvol to match the same as the one seen by the iscsi initiator side. So for instance if i'm creating an iscsi zvol for a NTFS volume , depending on the size of the zvol, i use from 4KB up to 64KB as seen in http://support.microsoft.com/?scid=kb%3Ben-us%3B140365&x=20&y=18 . Likewise if i'm going to use an EXT3 filesystem i try to use the same rules, as seen in http://en.wikipedia.org/wiki/Ext3#Size_limits .
This has been working good for me, but probably i'm not the best example since i "refuse" to provide iscsi zvol's on RAIDn implementations, i only use ZFS Mirrors for that.. Bruno -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
