From: Brad Campbell <brad@fnarfbargle.com>
To: Justin Piszcz <jpiszcz@lucidpixels.com>
Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org
Subject: Re: 3.10: discard/trim support on md-raid1?
Date: Sat, 13 Jul 2013 18:47:46 +0800 [thread overview]
Message-ID: <51E13052.30101@fnarfbargle.com> (raw)
In-Reply-To: <001701ce7fb4$889bdd40$99d397c0$@lucidpixels.com>
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
next prev parent reply other threads:[~2013-07-13 10:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-13 10:34 3.10: discard/trim support on md-raid1? Justin Piszcz
2013-07-13 10:34 ` Justin Piszcz
2013-07-13 10:47 ` Brad Campbell [this message]
2013-07-16 7:15 ` NeilBrown
2013-07-16 7:15 ` NeilBrown
2013-07-16 8:09 ` Justin Piszcz
2013-07-16 8:22 ` David Lang
2013-07-16 20:44 ` CoolCold
2013-07-17 1:48 ` NeilBrown
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