4
1
I got two drives of the same model which are connected using SATA.
When benchmarking read speeds using hdparm -t /dev/sdX
, speeds of about 160MB/s
are returned. When benchmarking write-speed using dd if=/dev/zero of=testfile bs=1M count=500 conv=fdatasync
, speeds of about 140MB/s
are returned.
However, when copying a single 10GB-file using rsync --progress /mnt/hd1/file /mnt/hd2/file
, the writespeed is only about 35MB/s
.
Why is it so slow? How can I make it faster?
What model? Are they SSDs? It is common with SSD that the write speed is some if not much lower than the read speed. – Dan D. – 2013-07-01T19:02:29.963
They are normal HDD's. When benchmarking, write speed is
140mb/s+
also. Seems to be an issue with rsync. – Zulakis – 2013-07-01T19:04:40.027Then it is possible that the file is rather fragmented. And the seeking which wasn't covered in your benchmarks is what is restricting the transfer speed. What does
filefrag /mnt/hd1/file
say when ran as root? – Dan D. – 2013-07-01T19:11:17.500"6 extends found". Is this a good or a bad value? – Zulakis – 2013-07-01T19:18:21.407
That is a good low value and that does eliminate seeking as the cause. – Dan D. – 2013-07-01T19:21:37.043