Hello,
I did some tests with 2.6.32-042stab037.1 kernel and it looks that IO priority has no impact on disk write operations.
2 identical VE on same disk (block device), one with IO priority 0 and other with IO priority 7. Results are pretty the same for both VE.
root@vps6:/# for i in 1 2 3 4 5; do dd if=/dev/zero of=test bs=64k count=32k conv=fdatasync; done
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 91.7144 s, 23.4 MB/s
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 70.1665 s, 30.6 MB/s
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 123.251 s, 17.4 MB/s
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 93.4022 s, 23.0 MB/s
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 126.531 s, 17.0 MB/s
root@vps7:/# for i in 1 2 3 4 5; do dd if=/dev/zero of=test bs=64k count=32k conv=fdatasync; done
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 98.4753 s, 21.8 MB/s
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 125.971 s, 17.0 MB/s
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 115.74 s, 18.6 MB/s
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 110.097 s, 19.5 MB/s
32768+0 records in
32768+0 records out
2147483648 bytes (2.1 GB) copied, 95.8683 s, 22.4 MB/s
am I doing something wrong ?
OpenVZ Forum
Members
Search
Help
Register
Login
Home
