Re: Very slow server I/O when copying a huge file (1.8GB)

Did you analyze your system swap stats during this copy process (u can
use vmstat 5 10).

Regards,

Uto Cen wrote:
Hi,
I'm running on 2.6.9 on an opteron with 2GB memory and 2 SATA drives.

Problem is everything is running fine, until a file copy of a very
large file (around 1.8GB) for backup purposes from one drive to the
other.
When the copy is in progress, apache grinds to a halt and as I run a
fairly busy site, new requests get queued until the apache MAX_CLIENT
(256) is hit, all this happening when there isn't any much swapping
(top shows 144kb swap used).

I've gathered some info, and tuned the vm.dirty_background_ratio=5 and
vm.dirty_ratio=10, but the result is the same.

Interesting note is that when i copied the huge file from the
secondary drive to the secondary drive, the result is the same - which
puzzles me because all executable binaries, data files, mysql database
are all on the first drive which shouldn't be impacted by the huge
copy on the secondary drive.

Any suggestions much appreciated.

TIA.

.