On 01/10/2014 02:35 PM, Wido den Hollander wrote:
Op 10 jan. 2014 om 18:49 heeft "Steffen Thorhauer"
<[email protected]
<mailto:[email protected]>> het volgende
geschreven:
On 01/10/2014 01:21 PM, Ирек Фасихов wrote:
You need to use VirtIO.
<target dev='*vdb*' bus='*virtio*'/>
with this parameter ist not a real performance increase:
dd if=/dev/zero of=zerofile-2 bs=1G count=8
8+0 records in
8+0 records out
8589934592 bytes (8.6 GB) copied, 73.8425 s, 116 MB/s
and reading:
trompete@multius:~$ dd if=zerofile-2 of=/dev/null bs=1G count=8
8+0 records in
8+0 records out
8589934592 bytes (8.6 GB) copied, 429.528 s, 20.0 MB/s
What happens if you increase the read_ahead_kb value for the device to
4096k. That is inside the guest.
cat read_ahead_kb
65536
trompete@multius:~$ dd if=zerofile-2 of=/dev/null bs=1G count=8
8+0 records in
8+0 records out
8589934592 bytes (8.6 GB) copied, 382.148 s, 22.5 MB/s
--
______________________________________________________________________
Steffen Thorhauer
Department of Technichal and Business Information Systems (ITI)
Faculty of Computer Science (FIN)
Otto von Guericke University Magdeburg
Universitaetsplatz 2
39106 Magdeburg, Germany
phone: 0391 67 52996
fax: 0391 67 12341
email: [email protected]
url: http://wwwiti.cs.uni-magdeburg.de/~thorhaue
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