Messages in this thread | | | Date | Sat, 13 Jul 2013 18:47:46 +0800 | From | Brad Campbell <> | Subject | Re: 3.10: discard/trim support on md-raid1? |
| |
On 13/07/13 18:34, Justin Piszcz wrote: > And possibly: > discard_zeroes_data: 1
Does it though?
Here's my 6 x SSD RAID10 that definitely discards.
brad@srv:~$ grep . /sys/block/md2/queue/* /sys/block/md2/queue/add_random:0 /sys/block/md2/queue/discard_granularity:33553920 /sys/block/md2/queue/discard_max_bytes:65536 /sys/block/md2/queue/discard_zeroes_data:0 /sys/block/md2/queue/hw_sector_size:512 /sys/block/md2/queue/iostats:0 /sys/block/md2/queue/logical_block_size:512 /sys/block/md2/queue/max_hw_sectors_kb:16383 /sys/block/md2/queue/max_integrity_segments:0 /sys/block/md2/queue/max_sectors_kb:512 /sys/block/md2/queue/max_segments:128 /sys/block/md2/queue/max_segment_size:65536 /sys/block/md2/queue/minimum_io_size:65536 /sys/block/md2/queue/nomerges:0 /sys/block/md2/queue/nr_requests:128 /sys/block/md2/queue/optimal_io_size:196608 /sys/block/md2/queue/physical_block_size:512 /sys/block/md2/queue/read_ahead_kb:384 /sys/block/md2/queue/rotational:1 /sys/block/md2/queue/rq_affinity:0 /sys/block/md2/queue/scheduler:none /sys/block/md2/queue/write_same_max_bytes:0
Mine does not have discard_zeroes_data == 1 which is correct as 3 of the drives are Samsung 830's and they don't return deterministic after trim.
I can verify that discard gets passed down the stack as I get a non-zero mismatch count after running a trim on the filesystem. Checking the mirrors manually sees 0 returned from the Intel 330's, and apparently random data returned from the 830's.
Regards, Brad
| |