I don't understand why. I have read many russian topics that a changing of scheduler doesn't help ... I don't think that only a changing of scheduler will help to me. But i only have changed the scheduler from cfq to deadline and 'dd' test now this:
# dd if=/dev/zero of=testfile.1gb bs=1M count=1000
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 13.7121 seconds, 76.5 MB/s
I determined main option:
Only this option helped to me:
# echo deadline > /sys/block/ sda/queue/ scheduler
I don't understand why. I have read many russian topics that a changing of scheduler doesn't help ... I don't think that only a changing of scheduler will help to me. But i only have changed the scheduler from cfq to deadline and 'dd' test now this:
# dd if=/dev/zero of=testfile.1gb bs=1M count=1000
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 13.7121 seconds, 76.5 MB/s
iowait sometime was only 80-90%.
Here my current setting:
# cat /proc/sys/ vm/vfs_ cache_pressure sda/queue/ scheduler sda/queue/ nr_requests
100
# cat /sys/block/
noop anticipatory [deadline] cfq
# cat /sys/block/
128
Now i will keep these setting and will watch there are a freezes or not.