I have installed RHEL 6.2 on intel 64 bit server and I have migrated Hitachi HUS-110 storage LU’s from DP pool on server.
I used following command to mount storage scsi device.
# mount –v –t ext4 –o discard /dev/sdb1 /home/tmp
It has mounted successfully with discard option. But when I run below command it give error.
# fstrim –v /home/tmp
Error -: “fstrim: /home/tmp” FITRIM ioctl failed : operation not supported”
When I discussed with Red Hat support, the told me to checked whether disk support discard option or not using following command.
" cat /sys/block/sdb/queue/discard_max_bytes " . If its non-zero then yes.
But in our case it is 0. It means my LU does not support discard option.
I have created DP pool and my migrated LU is belongs to DP pool and I am using ext4 file system also.
Please any one can tell be what is issue?