From: NeilBrown <neilb@suse.de>
To: loody <miloody@gmail.com>
Cc: Linux-FSDevel <linux-fsdevel@vger.kernel.org>
Subject: Re: dummy file read periodically for external USB Hard Disk
Date: Tue, 8 Jul 2014 13:01:27 +1000 [thread overview]
Message-ID: <20140708130127.0f29a46f@notabene.brown> (raw)
In-Reply-To: <CANudz+tNyzco0hAm0WEqE0X=MsjF=Ykmcs0jZf1p-XF7Zt+JsA@mail.gmail.com>
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On Mon, 7 Jul 2014 22:42:29 +0800 loody <miloody@gmail.com> wrote:
> hi all:
> we met a USB Hard Disk that will go to suspend if host stop
> sending scsi read command over 5mins.
> To save the IO, kernel will keep the file in page cache as much as
> he can and under this circumstances, the read command may disappear
> for a while longer enough to cause the device suspend.
>
> is there any kernel config or module parameter can do the dummy
> read periodically, even the sector 0 (MBR) is fine.
> or is there any kernel api I can use to read sector 0(MBR) maybe
> every 4mins?
>
> appreciate your help in advance,
> --
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Open the device with O_DIRECT and read a block every 4 minutes.
That should keep it awake.
NeilBrown
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next prev parent reply other threads:[~2014-07-08 3:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-07 14:42 dummy file read periodically for external USB Hard Disk loody
2014-07-08 3:01 ` NeilBrown [this message]
2014-07-08 3:17 ` Dave Jones
2014-07-08 15:00 ` loody
2014-07-09 14:13 ` loody
2014-07-10 0:47 ` NeilBrown
2014-07-11 9:04 ` loody
2014-07-12 3:01 ` Randy Dunlap
2014-07-18 17:31 ` loody
2014-07-18 18:13 ` Randy Dunlap
2014-07-19 10:59 ` loody
2014-07-19 11:02 ` loody
2014-07-19 21:19 ` Randy Dunlap
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