Hello, sorry that this posting is somewhat off topic. But maybe someone had the same problems when using dirvish and did find a solution?
I am using dirvish to backup files from my Linux system (debian/sid) to an external USB2 drive (a Seagate disc). I am running kernel 2.6.18. The hard disc is connected to an USB2 controller. The Problem: data transfer is very slow. It makes approx. 1 MByte/s only, but it should be more than 20 MByte/s. The hard disc is formatted as ext3fs and is mounted as > /dev/sde2 on /media/bak1 type ext3 (rw,nosuid,nodev,sync,noatime,data=ordered) I have tried several things: The fastest transfer is 23 MB/s by using dd to write a file directly to the disc: sync; time (dd if=/dev/zero of=foo count=100 bs=1048576; sync) 100+0 records in 100+0 records out 104857600 bytes (105 MB) copied, 4,45075 seconds, 23,6 MB/s real 0m4.559s ------------------------------- If I am copying the 100MB file from my internal hard disc to the external it takes much longer: sync; time (cp foo /media/bak1/test/;sync) real 1m24.978s user 0m0.008s sys 0m1.444s I have tried the same with rsync that was at similar speed. Trying it via rsync again after remounting the device was much faster!?!?! sync; time (rsync foo /media/bak1/test/;sync) real 0m11.064s ------------------------------- Because cp AFAIK cannot be configured to use different block sizes I have tried tar instead (the -b value is 20 per default): sync; time (tar cf /media/bak1/test/foo.tar foo; sync) real 0m40.504s user 0m0.016s sys 0m1.284s Using -b with different values does give different times: -b time (sec) ------------------ 2 4m52.585s 4 2m32.798s 8 1m25.332s 16 0m46.627s 20 0m40.504s 32 0m29.584s 64 0m19.463s 256 0m7.635s 512 0m6.128s I have also tried to mount the device as ext2fs or via data=writeback but that did not change anything. Do you have an idea what the problem might be? Ist there a solution? Thanks, Gert _______________________________________________ Dirvish mailing list [email protected] http://www.dirvish.org/mailman/listinfo/dirvish
