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Date: Mon, 26 May 2008 19:28:23 +0200
From: "Bart Van Assche" <bart.vanassche@gmail.com>
To: "Oliver Neukum" <oliver@neukum.org>
Subject: Re: Top 10 bugs/warnings for the week of March 23rd, 2008
Cc: "Theodore Tso" <tytso@mit.edu>, "Ingo Molnar" <mingo@elte.hu>,
       "Jan Kara" <jack@suse.cz>, "Arjan van de Ven" <arjan@linux.intel.com>,
       "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
       "Linus Torvalds" <torvalds@linux-foundation.org>,
       "Greg KH" <greg@kroah.com>, "Andrew Morton" <akpm@linux-foundation.org>
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On Mon, May 26, 2008 at 7:09 PM, Oliver Neukum <oliver@neukum.org> wrote:
> Am Montag 26 Mai 2008 19:01:48 schrieb Theodore Tso:
>> If the USB stack folks would like to work on how to recognize that
>> it's the same USB stick that had been previously pulled, so that it
>> gets the same block device, and we can decide for how long we should
>> keep dirty buffers around associated with a pulled USB stick, we can
>> certainly have that conversation.  :-)
>
> Even if we could tell whether the device has remained the same, how
> would we know the medium wasn't exchanged?

Looking at the filesystem UUID could help -- this is an ID that is
present as data on the disk, and that is even independent of the bus
type. See also /dev/disk/by-uuid.

For the journaling filesystems I am familiar with the default value
for the commit parameter is 5 seconds. Would it be a good idea to
leave the default to 5s for non-removable devices, and to change this
default to 1s for removable devices ?

Bart.