When I create a test image file based target on a sparse raw img file, I expect that from the initiatior to be able to issue SCSI UNMAP command (eg. blkdiscard/fstrim command from linux initiator)
Instead, the block device reports that it supports discard (lsblk -D shows DISC-MAX as non-zero) but effective command return is "Remote I/O error" when I try to unmap some blocks (using fstrim, blkdiscard or sg_unmap commands)
Therefore I conclude that the server supports the UNMAP command but it is disabled in the free license.
Please enable it for us the poor home people, too!
Thank you!
Code: Select all
root@linux:/tmp# (lsscsi -sdg; lsscsi -t)|grep -i kern
[5:0:0:0] disk KernSafe iSCSI Adapter 0200 /dev/sde [8:64] /dev/sg4 [21:4] 8.58GB
[5:0:0:0] disk iqn.2006-03.com.kernsafe:win81.imagefilesparse-raw-kernsafe,t,0x1 /dev/sde
root@linux:/tmp# lsblk -D /dev/sde
NAME DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO
sde 0 512B 256M 0
root@linux:/tmp# sg_unmap --lba=0x1 --num=1 /dev/sde
UNMAP not supported
root@linux:/tmp# blkdiscard -v /dev/sde
blkdiscard: /dev/sde: BLKDISCARD ioctl failed: Remote I/O error