Increase space of ZFS pool over iSCSI SAN, online

Solution 1:

This is a tricky one... In the past, a rescan of the LUN would work to get the OS to recognize the new device size. My formula used to be:

zpool set autoexpand=on vol1
# Then expand SAN or underlying disk array
echo 1 > /sys/class/scsi_disk/2\:0\:0\:1/device/rescan
zpool online -e vol1 /dev/sdb

The zpool online -e devicename used to work, but in newer versions of zfsonlinux, this action has been moved from userspace to the module load or a zpool export/import. It may not be able to be done online anymore. I reboot half the time or end up having to export/import the pool.

Solution 2:

The new size is normally taken into account automatically when the autoexpand property is set on the pool.

Otherwise, if exporting/importing the pool doesn't help, you can use this command:

zpool online -e pool device