From: Rogier Wolff <R.E.Wolff@BitWizard.nl>
To: Andreas Dilger <adilger@dilger.ca>
Cc: Rogier Wolff <R.E.Wolff@BitWizard.nl>, linux-ext4@vger.kernel.org
Subject: Re: Slow filesystem.
Date: Sat, 14 May 2011 07:45:53 +0200 [thread overview]
Message-ID: <20110514054553.GB6028@bitwizard.nl> (raw)
In-Reply-To: <0EBAA8CB-5EE3-477F-B4DE-51C72A0E1595@dilger.ca>
On Fri, May 13, 2011 at 11:21:52PM -0600, Andreas Dilger wrote:
> On May 13, 2011, at 06:59, Rogier Wolff wrote:
> > My work (as in what brings in money to buy things from) file-system is
> > now "slow as hell". Last time this happened you guys told me that this
> > was because I had millions of hardlinks and way too many files.
> >
> > Filesystem Inodes IUsed IFree IUse% Mounted on
> > /dev/md0 815M 4.1M 811M 1% /recover2
> >
> > I have only 4.1M files. Only 1% inodes "in use".
> >
> >
> > The filesystem was filling up lately, but i've managed to create some
> > free space.
> >
> > Filesystem Size Used Avail Use% Mounted on
> > /dev/md0 6.3T 5.3T 720G 89% /recover2
> I suspect that the free inodes in your filesystem are very
> fragmented, due to the filesystem filling up and then deleting a lot
> of files that create "holes" of free inodes within the inode table
> blocks. That means that possibly finding free inodes is a bunch of
> work, and then possibly only one or two inodes are allocated from
> each block.
How can the free inodes be fragmented?!? 99% of the available inodes
ARE free.
> > The question is: How do I get the filesystem to perform
> > normally again?
> It is probably worthwhile to do a blktrace to see what the IO is
> looking like, and as Eric suggested the oprofile information may be
> interesting if a lot of CPU is being used.
A lot of CPU time is being used, yes. The 62 milliseconds are almost
completely CPU time.
I was running a big "backup" (image of a 500Gb disk) onto the
partition. Now that this has finished I'll try booting into a recent
kernel. Next I'll try finding and applying the patch....
Roger.
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prev parent reply other threads:[~2011-05-14 5:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-13 12:59 Slow filesystem Rogier Wolff
2011-05-13 14:27 ` Eric Sandeen
2011-05-14 5:21 ` Andreas Dilger
2011-05-14 5:45 ` Rogier Wolff [this message]
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