Thanks, more Qs below ;) 2012-10-19 11:16, James C. McPherson wrote:
if you run /usr/bin/strings over /etc/zfs/zpool.cache, you'll see that not only is the device path stored, but (more importantly) the devid.
As an excerpt from my adventurous notebook, which only has an rpool on SAS, I see these lines IDE mode: # /usr/bin/strings /etc/zfs/zpool.cache ... path /dev/dsk/c3d0s0 devid 2id1,cmdk@ATOSHIBA_MK5061GSY=___________72LBP0S2T/a phys_path $/pci@0,0/pci-ide@11/ide@0/cmdk@0,0:a ... (I was wrong to say earlier that with VirtualBox I can dual-boot the VM in IDE mode flawlessly, on my last test there were also discrepancies: 'pci-ide@1,1' vs. 'pci-ide@11' so the rpool did not import too; I am not sure what the devid would be in that case). When the same notebook reconfigured into SATA mode I see: ... path /dev/dsk/c3t0d0s0 devid 6id1,sd@SATA_____TOSHIBA_MK5061GS___________72LBP0S2T/a phys_path #/pci@0,0/pci17aa,5104@11/disk@0,0:a ... Attacking my original problem and question, is any of these values expected to NOT change if the driver (HBA device) is changed, i.e. when switching between SATA and IDE modes? As seen above, devid apparently includes the driver/technology name (sd or cmdk), and identifiers (@tech_vendor_model_sernum) also differ, although some components do match at least partially. There are no problems with this when importing a "guest pool", such as getting an existing rpool while booted from LiveCD; panics only happen due to extra checks for the rpool import.
As far as I'm aware, having an rpool on multipathed devices is fine. Multiple paths to the device should still allow ZFS to obtain the same devid info... and we use devid's in preference to physical paths.
I do hope that in case of multipathing, the multiple paths use the same technology such as SAS or iSCSI, leading to the same devids which can be used reliably. Are there any real-life scenarios where a multipath can be implemented over several different transports, or people avoid that - just in case? In particular, can't the pool GUID be used for spa_import_rootpool? Thanks, //Jim _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
