Thanks for the replies, After some further testing.. When I ran a repair on the md's sync_action, the system would reduce I/O to the RAID-1 to 14kb/s or even less when it hit a certain number of blocks and effectively locked the system every time. It turned out to be a bad SSD (it also failed Intel's Secure Erase), I RMA'd it. Interesting though that it did not drop out of the array but froze the system (the failure scenario was odd). Justin. On Tue, Jul 16, 2013 at 3:15 AM, NeilBrown <neilb@xxxxxxx> wrote: > On Sat, 13 Jul 2013 06:34:19 -0400 "Justin Piszcz" <jpiszcz@xxxxxxxxxxxxxxx> > wrote: > >> Hello, >> >> Running 3.10 and I see the following for an md-raid1 of two SSDs: >> >> Checking /sys/block/md1/queue: >> add_random: 0 >> discard_granularity: 512 >> discard_max_bytes: 2147450880 >> discard_zeroes_data: 0 >> hw_sector_size: 512 >> iostats: 0 >> logical_block_size: 512 >> max_hw_sectors_kb: 32767 >> max_integrity_segments: 0 >> max_sectors_kb: 512 >> max_segment_size: 65536 >> max_segments: 168 >> minimum_io_size: 512 >> nomerges: 0 >> nr_requests: 128 >> optimal_io_size: 0 >> physical_block_size: 512 >> read_ahead_kb: 8192 >> rotational: 1 >> rq_affinity: 0 >> scheduler: none >> write_same_max_bytes: 0 >> >> What should be seen: >> rotational: 0 > > What has "rotational" got to do with "supports discard"? > There may be some correlation, but it isn't causal. > >> And possibly: >> discard_zeroes_data: 1 > > This should be set as the 'or' of the same value from component devices. And > does not enable or disable the use of discard. > > I don't think that "does this device support discard" appears in sysfs. > > I believe trim does work on md/raid1 if the underlying devices all support it. > > NeilBrown > > > >> >> Can anyone confirm if there is a workaround to allow TRIM when using >> md-raid1? >> >> Some related discussion here: >> http://us.generation-nt.com/answer/md-rotational-attribute-help-206571222.ht >> ml >> http://www.progtown.com/topic343938-ssd-strange-itself-conducts.html >> >> >> Justin. >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
