From: Douglas Gilbert <dgilbert@interlog.com>
To: joystick <joystick@shiftmail.org>
Cc: linux-ide@vger.kernel.org,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>
Subject: Re: TRIM / UNMAP read response
Date: Fri, 12 Aug 2011 10:55:29 -0400 [thread overview]
Message-ID: <4E453EE1.4050705@interlog.com> (raw)
In-Reply-To: <4E452A6E.4040809@shiftmail.org>
On 11-08-12 09:28 AM, joystick wrote:
> Hi all IDE and SCSI ml's,
>
> is it guaranteed by the standards that reading from a device a region that has
> been TRIMmed (IDE) or UNMAPped (SCSI) will certainly return zeroes?
ATA:
In 'hdparm -I' you need to see this line:
* Deterministic read ZEROs after TRIM
[See the ATA IDENTIFY DEVICE command]
SCSI:
In the READ CAPACITY (16) response the LBPRZ needs to
be set to 1. Recently the same LBPRZ bit was added to
the Logical Block Provisioning VPD page (sbc3r27.pdf).
Doug Gilbert
prev parent reply other threads:[~2011-08-12 14:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-12 13:28 TRIM / UNMAP read response joystick
2011-08-12 14:55 ` Douglas Gilbert [this message]
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