Linux Btrfs filesystem development
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From: David Sterba <dave@jikos.cz>
To: "Fajar A. Nugraha" <list@fajar.net>
Cc: "Hugo Mills" <hugo@carfax.org.uk>,
	"Swâmi Petaramesh" <swami@petaramesh.org>,
	linux-btrfs@vger.kernel.org
Subject: Re: BTRFS fsck apparent errors
Date: Wed, 4 Jul 2012 15:42:58 +0200	[thread overview]
Message-ID: <20120704134258.GL5326@twin.jikos.cz> (raw)
In-Reply-To: <CAG1y0scaAqck=LYJdfhQa02BsrnBM7=24RFG5j00pb0QSdn1LA@mail.gmail.com>

On Wed, Jul 04, 2012 at 07:40:05AM +0700, Fajar A. Nugraha wrote:
> Are there any known btrfs regression in 3.4? I'm using 3.4.0-3-generic
> from a ppa, but a normal mount - umount cycle seems MUCH longer
> compared to how it was on 3.2, and iostat shows the disk is
> read-IOPS-bound

Is it just mount/umount without any other activity? Is the fs
fragmented (or aged), almost full, has lots of files?

> 
> # time mount LABEL=WD-root
> 
> real	0m10.400s
> user	0m0.000s
> sys	0m0.060s
> 
> # time umount /media/WD-root/
> 
> real	0m22.419s
> user	0m0.000s
> sys	0m0.064s
> 
> # /proc/10142/stack  <--- the PID of umount process

The process(es) actually doing the work are the btrfs workers, usual
sucspects are btrfs-cache (free space cache) or btrfs-ino (inode cache)
that are writing the cache states back to disk.
I'm using iotop to observe such things.


david

  reply	other threads:[~2012-07-04 13:43 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-03 15:10 BTRFS fsck apparent errors Swâmi Petaramesh
2012-07-03 15:22 ` Hugo Mills
2012-07-03 15:52   ` David Sterba
2012-07-03 16:26     ` Zach Brown
2012-07-03 17:37       ` David Sterba
2012-07-03 17:42         ` Zach Brown
2012-07-04  3:25         ` Dave Chinner
2012-07-03 19:17   ` Swâmi Petaramesh
2012-07-04  0:40   ` Fajar A. Nugraha
2012-07-04 13:42     ` David Sterba [this message]
2012-07-04 15:46       ` Fajar A. Nugraha
2012-07-05  0:32         ` David Sterba

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