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From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Gionatan Danti <g.danti@assyoma.it>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
	Piergiorgio Sartor <piergiorgio.sartor@nexgo.de>,
	Seunguk Shin <seunguk.shin@samsung.com>,
	neilb@suse.de, linux-raid@vger.kernel.org
Subject: Re: [PATCH] raid0: data corruption when using trim
Date: Thu, 23 Jul 2015 18:17:18 -0400	[thread overview]
Message-ID: <yq1lhe6zfgx.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <55B11A68.4080706@assyoma.it> (Gionatan Danti's message of "Thu, 23 Jul 2015 18:46:32 +0200")

>>>>> "Gionatan" == Gionatan Danti <g.danti@assyoma.it> writes:

Gionatan> I *think* that, as this TRIM command is processed way above
Gionatan> the ATA layer (it is processed inside the device-mapper code),
Gionatan> the bug should not happen here. Is it correct? Are we safe
Gionatan> with ThinLVM + MDRAID10 + HDDs?

The problem only occurs if you are using MD linear/raid0/raid10 on top
of a device that implements either DSM TRIM (SATA) or UNMAP (SCSI). If
the device prefers WRITE SAME w/ UNMAP or if it does not support
discards at all there is no problem.

-- 
Martin K. Petersen	Oracle Linux Engineering

  reply	other threads:[~2015-07-23 22:17 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-19  3:28 [PATCH] raid0: data corruption when using trim Seunguk Shin
2015-07-20 12:33 ` Martin K. Petersen
2015-07-20 17:38   ` Piergiorgio Sartor
2015-07-20 18:26     ` Martin K. Petersen
2015-07-20 18:34       ` Piergiorgio Sartor
2015-07-21  4:28         ` Martin K. Petersen
2015-07-23 16:46           ` Gionatan Danti
2015-07-23 22:17             ` Martin K. Petersen [this message]
2015-07-24  6:37               ` Gionatan Danti
2015-07-21  4:18   ` Seunguk Shin
2015-07-21  4:55     ` Martin K. Petersen
2015-07-22 11:21       ` Seunguk Shin
2015-07-22 11:59         ` Martin K. Petersen
2015-07-24  6:47         ` Gionatan Danti
     [not found]           ` <023401d0c60a$fff39330$ffdab990$@samsung.com>
2015-07-24 14:42             ` Gionatan Danti
2015-07-24 15:03           ` Martin K. Petersen

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