Hi! A dm-era device created over a RAID5 array loses discard support.
Test script is attached. If you run it on SSD you'll see something like: loop0 4096 loop1 4096 loop2 4096 loop3 4096 md55 1048576 loop_test_era 0 I.e. mdadm device supports discard, but dm-era device started over it doesn't. If you create a dm-era device over a normal block device without mdadm RAID5 or even over mdadm RAID1 - it will preserve discard support. Why? How can it be fixed? -- With best regards, Vitaliy Filippov
raid5_test.sh
Description: Binary data
-- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel