From: Mark Lord <kernel@teksavvy.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@infradead.org>,
xfs@oss.sgi.com, Linux Kernel <linux-kernel@vger.kernel.org>,
Alex Elder <aelder@sgi.com>
Subject: Re: xfs: very slow after mount, very slow at umount
Date: Wed, 26 Jan 2011 22:53:17 -0500 [thread overview]
Message-ID: <4D40EC2D.5020507@teksavvy.com> (raw)
In-Reply-To: <20110127034314.GI21311@dastard>
On 11-01-26 10:43 PM, Dave Chinner wrote:
> On Wed, Jan 26, 2011 at 08:43:43PM -0500, Mark Lord wrote:
>> On 11-01-26 08:22 PM, Mark Lord wrote:
..
>> Thinking about it some more: the first problem very much appears as if
>> it is due to a filesystem check happening on the already-mounted filesystem,
>> if that makes any kind of sense (?).
>
> Not to me. You can check this simply by looking at the output of
> top while the problem is occurring...
Top doesn't show anything interesting, since disk I/O uses practically zero CPU.
>> running xfs_check on the umounted drive takes about the same 30-60 seconds,
>> with the disk activity light fully "on".
>
> Well, yeah - XFS check reads all the metadata in the filesystem, so
> of course it's going to thrash your disk when it is run. The fact it
> takes the same length of time as whatever problem you are having is
> likely to be coincidental.
I find it interesting that the mount takes zero-time,
as if it never actually reads much from the filesystem.
Something has to eventually read the metadata etc.
>> The other thought that came to mind: this behaviour has only been
>> noticed recently, probably because I have recently added about
>> 1000 new files (hundreds of MB each) to the videos/ directory on
>> that filesystem. Whereas before, it had fewer than 500 (multi-GB)
>> files in total.
>>
>> So if it really is doing some kind of internal filesystem check,
>> then the time required has only recently become 3X larger than
>> before.. so the behaviour may not be new/recent, but now is very
>> noticeable.
>
> Where does that 3x figure come from?
Well, it used to have about 500 files/subdirs on it,
and now it has somewhat over 1500 files/subdirs.
That's a ballpark estimate of 3X the amount of meta data.
All of these files are at least large (hundreds of MB),
and a lot are huge (many GB) in size.
Cheers
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
WARNING: multiple messages have this Message-ID (diff)
From: Mark Lord <kernel@teksavvy.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Alex Elder <aelder@sgi.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
xfs@oss.sgi.com
Subject: Re: xfs: very slow after mount, very slow at umount
Date: Wed, 26 Jan 2011 22:53:17 -0500 [thread overview]
Message-ID: <4D40EC2D.5020507@teksavvy.com> (raw)
In-Reply-To: <20110127034314.GI21311@dastard>
On 11-01-26 10:43 PM, Dave Chinner wrote:
> On Wed, Jan 26, 2011 at 08:43:43PM -0500, Mark Lord wrote:
>> On 11-01-26 08:22 PM, Mark Lord wrote:
..
>> Thinking about it some more: the first problem very much appears as if
>> it is due to a filesystem check happening on the already-mounted filesystem,
>> if that makes any kind of sense (?).
>
> Not to me. You can check this simply by looking at the output of
> top while the problem is occurring...
Top doesn't show anything interesting, since disk I/O uses practically zero CPU.
>> running xfs_check on the umounted drive takes about the same 30-60 seconds,
>> with the disk activity light fully "on".
>
> Well, yeah - XFS check reads all the metadata in the filesystem, so
> of course it's going to thrash your disk when it is run. The fact it
> takes the same length of time as whatever problem you are having is
> likely to be coincidental.
I find it interesting that the mount takes zero-time,
as if it never actually reads much from the filesystem.
Something has to eventually read the metadata etc.
>> The other thought that came to mind: this behaviour has only been
>> noticed recently, probably because I have recently added about
>> 1000 new files (hundreds of MB each) to the videos/ directory on
>> that filesystem. Whereas before, it had fewer than 500 (multi-GB)
>> files in total.
>>
>> So if it really is doing some kind of internal filesystem check,
>> then the time required has only recently become 3X larger than
>> before.. so the behaviour may not be new/recent, but now is very
>> noticeable.
>
> Where does that 3x figure come from?
Well, it used to have about 500 files/subdirs on it,
and now it has somewhat over 1500 files/subdirs.
That's a ballpark estimate of 3X the amount of meta data.
All of these files are at least large (hundreds of MB),
and a lot are huge (many GB) in size.
Cheers
next prev parent reply other threads:[~2011-01-27 3:50 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-27 1:22 xfs: very slow after mount, very slow at umount Mark Lord
2011-01-27 1:43 ` Mark Lord
2011-01-27 3:43 ` Dave Chinner
2011-01-27 3:43 ` Dave Chinner
2011-01-27 3:53 ` Mark Lord [this message]
2011-01-27 3:53 ` Mark Lord
2011-01-27 4:54 ` Mark Lord
2011-01-27 4:54 ` Mark Lord
2011-01-27 23:34 ` Dave Chinner
2011-01-27 23:34 ` Dave Chinner
2011-01-27 3:30 ` Dave Chinner
2011-01-27 3:30 ` Dave Chinner
2011-01-27 3:49 ` Mark Lord
2011-01-27 3:49 ` Mark Lord
2011-01-27 5:17 ` Stan Hoeppner
2011-01-27 15:12 ` Mark Lord
2011-01-27 15:12 ` Mark Lord
2011-01-27 15:40 ` Justin Piszcz
2011-01-27 15:40 ` Justin Piszcz
2011-01-27 16:03 ` Mark Lord
2011-01-27 16:03 ` Mark Lord
2011-01-27 19:40 ` Stan Hoeppner
2011-01-27 19:40 ` Stan Hoeppner
2011-01-27 20:11 ` david
2011-01-27 20:11 ` david
2011-01-27 23:53 ` Stan Hoeppner
2011-01-27 23:53 ` Stan Hoeppner
2011-01-28 2:09 ` david
2011-01-28 2:09 ` david
2011-01-28 13:56 ` Dave Chinner
2011-01-28 13:56 ` Dave Chinner
2011-01-28 19:26 ` david
2011-01-28 19:26 ` david
2011-01-29 5:40 ` Dave Chinner
2011-01-29 5:40 ` Dave Chinner
2011-01-29 6:08 ` david
2011-01-29 6:08 ` david
2011-01-29 7:35 ` Dave Chinner
2011-01-29 7:35 ` Dave Chinner
2011-01-31 19:17 ` Christoph Hellwig
2011-01-31 19:17 ` Christoph Hellwig
2011-01-27 21:56 ` Mark Lord
2011-01-27 21:56 ` Mark Lord
2011-01-28 0:17 ` Dave Chinner
2011-01-28 0:17 ` Dave Chinner
2011-01-28 1:22 ` Mark Lord
2011-01-28 1:22 ` Mark Lord
2011-01-28 1:36 ` Mark Lord
2011-01-28 1:36 ` Mark Lord
2011-01-28 4:14 ` David Rees
2011-01-28 4:14 ` David Rees
2011-01-28 14:22 ` Mark Lord
2011-01-28 14:22 ` Mark Lord
2011-01-28 7:31 ` Dave Chinner
2011-01-28 7:31 ` Dave Chinner
2011-01-28 14:33 ` Mark Lord
2011-01-28 14:33 ` Mark Lord
2011-01-28 23:58 ` Dave Chinner
2011-01-28 23:58 ` Dave Chinner
2011-01-28 19:18 ` Martin Steigerwald
2011-01-28 19:18 ` Martin Steigerwald
2011-01-27 20:24 ` John Stoffel
2011-01-27 20:24 ` John Stoffel
2011-01-27 23:41 ` Dave Chinner
2011-01-27 23:41 ` Dave Chinner
2011-01-28 0:59 ` Mark Lord
2011-01-28 0:59 ` Mark Lord
2011-01-27 23:39 ` Dave Chinner
2011-01-27 23:39 ` Dave Chinner
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=4D40EC2D.5020507@teksavvy.com \
--to=kernel@teksavvy.com \
--cc=aelder@sgi.com \
--cc=david@fromorbit.com \
--cc=hch@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=xfs@oss.sgi.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.