Hi, thanks for your replies and sorry for my delay in answering. Joseph Loo wrote:
Franz Petri wrote:
Hi,
I have a problem getting the performance up when writing to an external harddisk, connected via usb 2.0.
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Another item check to see how it is mounted. Do a cat /proc/mounts. this will help determine if you are running synch versus asynch. Synch slows the operation significantly.
It seems that synch mode was indeed the cause for this. ~> cat /proc/mounts rootfs / rootfs rw 0 0 udev /dev tmpfs rw 0 0 /dev/hda2 / ext3 rw,data=ordered 0 0 proc /proc proc rw 0 0 sysfs /sys sysfs rw 0 0 debugfs /sys/kernel/debug debugfs rw 0 0 devpts /dev/pts devpts rw 0 0 /dev/hda3 /home ext3 rw,data=ordered 0 0 securityfs /sys/kernel/security securityfs rw 0 0 /dev/sda2 /media/disk reiserfs rw,sync,nosuid,nodev 0 0 /dev/sda1 /media/disk-1 vfat rw,nosuid,nodev,noatime,uid=1003,fmask=0022,dmask=0022,codepage=cp437,iocharset=iso8859-1,utf8 0 0 ~> ~> dd if=/dev/zero of=/media/disk/tmp/tmp.txt count=1000 1000+0 records in 1000+0 records out 512000 bytes (512 kB) copied, 2.57634 s, 199 kB/s I usually let kde do all the mounting of external SD-cards, usb-drives, cd-rom, ect. So I went to "drive properties" via sysinfo:/ and unchecked "Sync", then "safely removed" the usb disk and mounted again (via kde-interface). This is what it looks like now: ~> cat /proc/mounts rootfs / rootfs rw 0 0 udev /dev tmpfs rw 0 0 /dev/hda2 / ext3 rw,data=ordered 0 0 proc /proc proc rw 0 0 sysfs /sys sysfs rw 0 0 debugfs /sys/kernel/debug debugfs rw 0 0 devpts /dev/pts devpts rw 0 0 /dev/hda3 /home ext3 rw,data=ordered 0 0 securityfs /sys/kernel/security securityfs rw 0 0 /dev/sda1 /media/disk-1 vfat rw,nosuid,nodev,noatime,uid=1003,fmask=0022,dmask=0022,codepage=cp437,iocharset=iso8859-1,utf8 0 0 /dev/sda2 /media/disk reiserfs rw,nosuid,nodev 0 0 ~> ~> dd if=/dev/zero of=/media/disk/tmp/tmp.txt count=1000 1000+0 records in 1000+0 records out 512000 bytes (512 kB) copied, 0.0472442 s, 10.8 MB/s ~> This is at least a reasonable magnitude of the transfer rate. So the problem is solved for now for me. BUT: As google finds the risk of data loss being the biggest drawback of the async mode, some questions remain: - Is "safely remove" via kde the way to go at all to finish off all transfers? - Can I trust kde to properly flush and umount everything when shutting the PC down, or do I have to "Safely remove" everytime before I shut down? - Is there a certain idle time period after which I can assume no harm to my data, even when I just unplug the usb drive without "safely remove"? Thanks, Franz.