linux-ext4.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: SandeepKsinha <sandeepksinha@gmail.com>
To: Greg Freemyer <greg.freemyer@gmail.com>
Cc: Akira Fujita <a-fujita@rs.jp.nec.com>,
	Theodore Tso <tytso@mit.edu>,
	ext4 development <linux-ext4@vger.kernel.org>
Subject: Re: Question about ext4 online defrag test case
Date: Fri, 15 Jan 2010 19:11:28 +0530	[thread overview]
Message-ID: <37d33d831001150541o1b674580u14719e72e3ad8e78@mail.gmail.com> (raw)
In-Reply-To: <87f94c371001141304n18bcd208kd97f08646d37d1e2@mail.gmail.com>

On Fri, Jan 15, 2010 at 2:34 AM, Greg Freemyer <greg.freemyer@gmail.com> wrote:
> On Thu, Jan 14, 2010 at 5:19 AM, Akira Fujita <a-fujita@rs.jp.nec.com> wrote:
>> Hi Ted,
>>
>>> E2defrag should hopefully be releasable in Karmic+1.
>>> There are still a lot of bugs that are still being fixed in the defrag
>>> code,
>>> some of which could cause data loss. They work fine
>>> if the system isn't under stress, sure, but acid test is to make sure
>>> things work OK even when the system is under memory pressure and
>>> swapping heavily, or when the file is being actively modified at the point
>>> where the defrag takes place.
>>
>> I found your comment about ext4 online defrag on Ubuntu BBS by accident.
>> https://bugs.launchpad.net/ubuntu/+source/e2fsprogs/+bug/321528
>>
>> I would like to address this problem so I ran e4defrag on the system
>> which was under memory pressure. But unfortunately I could not find the bug.
>> If you have already known how to reproduce this kind of problem,
>> could you teach me how?
>>
>> Regards,
>> Akira Fujita
>
> Sandeep, I've added you and I to this thread since oshm is using the
> same ext4_move_extents ioctl as E2defrag.
>
> Also, the above highlights the need for us to test ohsm relocates with
> data updates in progress.  Also with memory pressure which I had not
> really thought about before.
>

We have been testing ext4_move_extent through OHSM relocation till now.
Also, we have been testing it on real-world data
(http://edrm.net/activities/projects/data-set).

But yes we surely need to test then on a system under memory pressure.

> We can discuss that on the ohsm list if needed.
>
> Greg
>

-- 
Regards,
Sandeep
OHSM Team
https://sourceforge.net/projects/ohsm/


“To learn is to change. Education is a process that changes the learner.”
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2010-01-15 13:41 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-14 10:19 Question about ext4 online defrag test case Akira Fujita
2010-01-14 21:04 ` Greg Freemyer
2010-01-15 13:41   ` SandeepKsinha [this message]
2010-01-16  6:29     ` tytso
2010-01-16 17:28       ` Manish Katiyar
2010-01-19  4:37       ` Akira Fujita

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=37d33d831001150541o1b674580u14719e72e3ad8e78@mail.gmail.com \
    --to=sandeepksinha@gmail.com \
    --cc=a-fujita@rs.jp.nec.com \
    --cc=greg.freemyer@gmail.com \
    --cc=linux-ext4@vger.kernel.org \
    --cc=tytso@mit.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).