Bill, I realized just now that we're actually sending the wrong variant of SYNCHRONIZE CACHE, at least for SCSI devices which support SBC-2.
SBC-2 (or possibly even SBC-1, I don't have it handy) added the SYNC_NV bit to the command. If SYNC_NV is set to 0, the device is required to flush data from any non-volatile cache to the storage medium. If SYNC_NV is 1, however, the device is only required to ensure that data in any volatile caches is flushed to non-volatile cache if present. We should be setting SYNC_NV for devices which support SBC-2. This should solve the problem where the larger array systems are flushing their non-volatile cache to disk when ZFS sends the cache flush; though, of course, it assumes that vendors actually check this bit. ;-) Should I file a bug on this? Anton This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
