It seems that http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5.2/html/Online_Storage_Reconfiguration_Guide/ was recently posted. Previously the work in progress could only be found in an obscure bugzilla.
The main reason I see to resize LUNs and rescan, rather than add a PV, is to ensure that SAN-level snapshots and replications are consistent. Your SAN may not be able to guarantee that multiple PVs are snapshotted at exactly the same moment. I've added some comments to Domenico Viggiani's suggestions prepended by *** *** A shorter path is /dev/sdd/device/rescan. You can find "sdd" *** by parsing multipath -ll, or by tracing "slaves/" in /sys/block/dm-*. *** Your method is required in RHEL4 which doesn't provide these links. # Rescan devices (for all 4 paths) echo "1" > /sys/bus/scsi/drivers/sd/<h>\:<b>\:<t>\:<l>/block/device/rescan ... # Check /var/log/messages # Trespass LUN by Navisphere # Rescan devices (for all 4 paths) echo "1" > /sys/bus/scsi/drivers/sd/<h>\:<b>\:<t>\:<l>/block/device/rescan ... # Check /var/log/messages # Umount filesystem # Deactivate VG vgchange -an vg_LUN *** You might want to multipath -f specific_multipath rather than doing *** multipath -f. I highly recommend setting pretty names using wwid *** aliases in multipath.conf. # Delete and recreate multipath device multipath -F multipath -v2 multipath -ll # Activate VG vgchange -ay vg_LUN *** Is it really safe to remount here? I wait until after the *** pvresize/lvextend finish. # Remount filesystem # Extend PV pvresize /dev/mapper/<long-multipath-identifier> # Check VG vgdisplay -v vg_LUN # Extend LV lvextend -l +256 /dev/vg_LUN/lvol... # Extend FS ext2online /dev/vg_LUN/lvol... -- Rich Graves http://claimid.com/rcgraves Carleton.edu Sr UNIX and Security Admin CMC135: 507-646-7079 Cell: 952-292-6529 _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
