From: "Joseph D. Wagner" <joe@josephdwagner.info>
To: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
Subject: Re: dump ext4 performance degrades linearly as disk fills
Date: Tue, 17 Jun 2014 07:08:43 -0700 [thread overview]
Message-ID: <53A04BEB.7000401@josephdwagner.info> (raw)
In-Reply-To: <20140616124229.GA8465@thunk.org>
On 06/16/2014 05:42 AM, Theodore Ts'o wrote:
> Something that might help is simply running "dumpe2fs /dev/sdXX >
> /dev/null" or "e2freefrag /dev/hdXX > /dev/null" after you mount the
> file system and before you kick off the backup. This will load all of
> the block allocation bitmaps into the buffer cache, and the libext2fs
> functions used by dumpe2fs and e2freefrag will do so much more
> efficiently than the kernel code will as it demand-loads the bitmap
> blocks. Hope this helps! - Ted
I just got done trying that. Below is what I am seeing. It seemed to
do well up until 20%, but then performance drops. Between 31% and 33%,
I reran dumpe2fs in case this was some sort of cache poison issue. As
you can see, it didn't improve performance at the time.
FYI, lvbackup is a script I wrote to 1) create to lvm snapshot, 2) run
dump, and 3) drop the snapshot.
# su -c 'cd /root; dumpe2fs /dev/mapper/backup > /dev/null; nice ionice
-c3 /usr/local/bin/lvbackup /dev/data/home /mnt/backup'
Password:
dumpe2fs 1.42.8 (20-Jun-2013)
DUMP: mount: bad UUID
DUMP: Date of this level 0 dump: Mon Jun 16 20:08:57 2014
DUMP: Dumping /dev/data/backup-data-home (an unlisted file system) to
/mnt/backup/backup-data-home-20140616.200856-0.img
DUMP: Label: none
DUMP: Writing 64 Kilobyte records
DUMP: mapping (Pass I) [regular files]
DUMP: mapping (Pass II) [directories]
DUMP: estimated 1722505007 blocks.
DUMP: writing QFA positions to
/mnt/backup/backup-data-home-20140616.200856-0.qfa
DUMP: Volume 1 started with block 1 at: Mon Jun 16 20:09:11 2014
DUMP: dumping (Pass III) [directories]
DUMP: dumping (Pass IV) [regular files]
DUMP: 1.92% done at 110516 kB/s, finished in 4:14
DUMP: 4.05% done at 116142 kB/s, finished in 3:57
DUMP: 6.27% done at 119939 kB/s, finished in 3:44
DUMP: 8.51% done at 122095 kB/s, finished in 3:35
DUMP: 10.73% done at 123209 kB/s, finished in 3:28
DUMP: 12.89% done at 123382 kB/s, finished in 3:22
DUMP: 14.98% done at 122868 kB/s, finished in 3:18
DUMP: 17.05% done at 122380 kB/s, finished in 3:14
DUMP: 18.98% done at 121068 kB/s, finished in 3:12
DUMP: 20.37% done at 116976 kB/s, finished in 3:15
DUMP: 21.72% done at 113360 kB/s, finished in 3:18
DUMP: 23.12% done at 110641 kB/s, finished in 3:19
DUMP: 24.40% done at 107777 kB/s, finished in 3:21
DUMP: 25.76% done at 105628 kB/s, finished in 3:21
DUMP: 27.08% done at 103641 kB/s, finished in 3:21
DUMP: 28.30% done at 101527 kB/s, finished in 3:22
DUMP: 29.50% done at 99508 kB/s, finished in 3:23
DUMP: 30.79% done at 98101 kB/s, finished in 3:22
DUMP: 31.88% done at 96210 kB/s, finished in 3:23
DUMP: 33.31% done at 95509 kB/s, finished in 3:20
DUMP: 34.50% done at 94219 kB/s, finished in 3:19
DUMP: 35.86% done at 93449 kB/s, finished in 3:17
DUMP: 37.25% done at 92860 kB/s, finished in 3:14
DUMP: 38.64% done at 92323 kB/s, finished in 3:10
DUMP: 39.91% done at 91559 kB/s, finished in 3:08
DUMP: 41.18% done at 90845 kB/s, finished in 3:05
DUMP: 42.59% done at 90476 kB/s, finished in 3:02
DUMP: 43.88% done at 89885 kB/s, finished in 2:59
DUMP: 45.09% done at 89188 kB/s, finished in 2:56
DUMP: 46.45% done at 88794 kB/s, finished in 2:53
DUMP: 47.77% done at 88370 kB/s, finished in 2:49
DUMP: 49.12% done at 88029 kB/s, finished in 2:45
DUMP: 50.36% done at 87518 kB/s, finished in 2:42
DUMP: 51.53% done at 86929 kB/s, finished in 2:40
DUMP: 52.65% done at 86276 kB/s, finished in 2:37
DUMP: 53.97% done at 85979 kB/s, finished in 2:33
DUMP: 55.30% done at 85720 kB/s, finished in 2:29
DUMP: 56.58% done at 85388 kB/s, finished in 2:25
DUMP: 57.91% done at 85158 kB/s, finished in 2:21
DUMP: 59.30% done at 85024 kB/s, finished in 2:17
DUMP: 60.66% done at 84848 kB/s, finished in 2:13
DUMP: 61.94% done at 84576 kB/s, finished in 2:09
DUMP: 63.21% done at 84299 kB/s, finished in 2:05
DUMP: 64.24% done at 83730 kB/s, finished in 2:02
DUMP: 65.37% done at 83309 kB/s, finished in 1:59
DUMP: 66.48% done at 82892 kB/s, finished in 1:56
DUMP: 67.69% done at 82599 kB/s, finished in 1:52
DUMP: 68.76% done at 82161 kB/s, finished in 1:49
DUMP: 69.90% done at 81788 kB/s, finished in 1:45
DUMP: 70.95% done at 81365 kB/s, finished in 1:42
DUMP: 72.13% done at 81094 kB/s, finished in 1:38
DUMP: 73.33% done at 80861 kB/s, finished in 1:34
DUMP: 74.42% done at 80510 kB/s, finished in 1:31
DUMP: 75.51% done at 80186 kB/s, finished in 1:27
DUMP: 76.65% done at 79919 kB/s, finished in 1:23
DUMP: 77.72% done at 79577 kB/s, finished in 1:20
DUMP: 78.74% done at 79212 kB/s, finished in 1:17
DUMP: 79.92% done at 79016 kB/s, finished in 1:12
DUMP: 81.00% done at 78728 kB/s, finished in 1:09
DUMP: 82.20% done at 78564 kB/s, finished in 1:05
DUMP: 83.33% done at 78344 kB/s, finished in 1:01
DUMP: 84.39% done at 78048 kB/s, finished in 0:57
DUMP: 85.19% done at 77542 kB/s, finished in 0:54
DUMP: 86.20% done at 77237 kB/s, finished in 0:51
DUMP: 87.19% done at 76919 kB/s, finished in 0:47
DUMP: 88.13% done at 76568 kB/s, finished in 0:44
DUMP: 89.14% done at 76289 kB/s, finished in 0:40
DUMP: 90.08% done at 75961 kB/s, finished in 0:37
DUMP: 91.20% done at 75791 kB/s, finished in 0:33
DUMP: 92.34% done at 75646 kB/s, finished in 0:29
DUMP: 93.56% done at 75563 kB/s, finished in 0:24
DUMP: 94.69% done at 75415 kB/s, finished in 0:20
DUMP: 95.77% done at 75203 kB/s, finished in 0:16
DUMP: 96.83% done at 74995 kB/s, finished in 0:12
DUMP: 97.79% done at 74733 kB/s, finished in 0:08
DUMP: 98.74% done at 74465 kB/s, finished in 0:04
DUMP: 99.67% done at 74171 kB/s, finished in 0:01
DUMP: Closing /mnt/backup/backup-data-home-20140616.200856-0.img
DUMP: Volume 1 completed at: Tue Jun 17 02:36:40 2014
DUMP: Volume 1 1722545856 blocks (1682173.69MB)
DUMP: Volume 1 took 6:27:29
DUMP: Volume 1 transfer rate: 74091 kB/s
DUMP: 1722545856 blocks (1682173.69MB) on 1 volume(s)
DUMP: finished in 23249 seconds, throughput 74091 kBytes/sec
DUMP: Date of this level 0 dump: Mon Jun 16 20:08:57 2014
DUMP: Date this dump completed: Tue Jun 17 02:36:40 2014
DUMP: Average transfer rate: 74091 kB/s
DUMP: Archiving dump to
/mnt/backup/backup-data-home-20140616.200856-0.toc
DUMP: DUMP IS DONE
Logical volume "backup-data-home" successfully removed
next prev parent reply other threads:[~2014-06-17 14:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-16 5:43 dump ext4 performance degrades linearly as disk fills Joseph D. Wagner
2014-06-16 12:42 ` Theodore Ts'o
2014-06-17 14:08 ` Joseph D. Wagner [this message]
2014-06-17 14:51 ` Theodore Ts'o
2014-06-16 21:48 ` Andreas Dilger
-- strict thread matches above, loose matches on Subject: below --
2014-06-19 18:42 Joseph D. Wagner
2014-06-21 0:38 ` Theodore Ts'o
2014-07-29 20:55 ` Phillip Susi
2014-07-29 22:48 ` Joseph D. Wagner
2014-06-20 23:59 Joseph D. Wagner
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