Jan, > I'm wondering if it's possible to import a zpool on an iscsi-device > LOCALLY. > > Following scenario: > > HostA (Sol10u4): > - Pool-1 (a striped-raidz-pool) > - iscsi-zvol on Pool-1 > > HostB (Sol10u3): > - Pool-2 is a Mirror of one local device and the iscsi-vol of HostA > > Is ist possible to mount the iscsi-vol (or import Pool-2) on HostA?
No, due to a common misconception in the iSCSI space, spanning an iSCSI Target's backing store, to the resulting LUN as seen by iSCSI Initiators. On HostA, the ZVOL called iscsi-zvol has a volume size, a size specified in the "zfs create -V <size> Pool-1/iscsi-zvol". When an iSCSI Target is created out of this ZVOL, then the iSCSI Initiator discovers and enables this LUN on HostB, but this LUN is unformatted. In other words, this LUN does not contain a Solaris VTOC or an Intel EFI disk label, as its just a bunch of blocks. When issuing the "zpool create Pool-2 mirror <local-disk> <iscsi-vol>", an Intel EFI disk label is placed on the disk (consuming some of the blocks), then all the remaining space is placed in partition (or slice 0), after which ZFS lays down its filesystem metadata in the space occupied by partition 0. Now back on HostA, the ZVOL ( /dev/zvol/rdsk/Pool-1/iscsi-zvol ) looks like a bunch of blocks. Since this is a ZVOL, not a SCSI or iSCSI LUN, Solaris does not see the Intel EFI disk label, thus ZFS will not be able to see the ZFS filesystem metadata. So even though the ZVOL contains all the right data, from the point of view of Solaris, this disk is not a LUN, and thus can not be accessed as such. Jim > > > I know, this is (also) iSCSI-related, but mostly a ZFS-question. > > Thanks for your answers, > Jan Dreyer > _______________________________________________ > zfs-discuss mailing list > [email protected] > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss Jim Dunham Storage Platform Software Group Sun Microsystems, Inc. wk: 781.442.4042 http://blogs.sun.com/avs http://www.opensolaris.org/os/project/avs/ http://www.opensolaris.org/os/project/iscsitgt/ http://www.opensolaris.org/os/community/storage/ _______________________________________________ zfs-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
