From: Zoltan Szecsei <zoltans@geograph.co.za>
To: linux-raid@vger.kernel.org
Subject: Array read 3 time slower to read after data fully loaded
Date: Thu, 18 Nov 2010 07:30:14 +0200 [thread overview]
Message-ID: <4CE4B9E6.1040802@geograph.co.za> (raw)
Hi,
Can anyone please explain this to me?
For the last >30 hours I have been loading some 2.5TB of 200-400MB tiff
images, from another PC on our internal network, onto this new array.
Yesterday, during this load process, I copied 10 of these files (about
2.5GB) from the array onto the /home directory of the same system.
It took 33 seconds, equating to some 75MB/s.
This morning I came in to find that the load process had finished, so I
deleted the 10 test files from /home, and redid the identical copy test
(using bash-history, so: identical).
It took 123 seconds, equating to some 20MB/s.
Que? (as in Manuel from Faulty Towers :-) )
Thanks & regards,
Zoltan
root@gs0:/home/geograph# uname -a
Linux gs0 2.6.32-25-generic #45-Ubuntu SMP Sat Oct 16 19:52:42 UTC 2010
x86_64 GNU/Linux
root@gs0:/home/geograph# mdadm -V
mdadm - v3.1.4 - 31st August 2010
root@gs0:/home/geograph# lvm version
LVM version: 2.02.54(1) (2009-10-26)
Library version: 1.02.39 (2009-10-26)
Driver version: 4.15.0
root@gs0:/home/geograph# df #ext4
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdi7 426559760 9494844 395396872 3% /home
/dev/mapper/geo_vg0-geo_lvm0
11536635672 2530042680 8889387468 23% /mnt/geo_lvm0
root@gs0:/home/geograph#
--
===========================================
Zoltan Szecsei PrGISc [PGP0031]
Geograph (Pty) Ltd.
P.O. Box 7, Muizenberg 7950, South Africa.
65 Main Road, Muizenberg 7945
Western Cape, South Africa.
34° 6'16.35"S 18°28'5.62"E
Tel: +27-21-7884897 Mobile: +27-83-6004028
Fax: +27-86-6115323 www.geograph.co.za
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next reply other threads:[~2010-11-18 5:30 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-18 5:30 Zoltan Szecsei [this message]
2010-11-18 20:43 ` Array read 3 time slower to read after data fully loaded Michal Soltys
2010-11-18 20:53 ` David Lethe
2010-11-22 4:18 ` Neil Brown
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