Jan Romportl wrote:
Hello everyone,
could you please give me an advice how to solve the following problem:
I've got an external 200GB Maxtor USB harddisk. In SUSE 9.3 it is automatically mounted as a subfs hotplug device to /media/usb_disk. It is mounted with synchronous acces (i.e. sync option for mount). However, this sync causes that the writing speed can be only 2MB/s with 100% cpu load (it normally writes about 20MB/s). In SUSE 9.2 I figured out that when it is mounted without sync, the performance is OK (i.e. 20MB/s writing). I have modified /etc/hotplug/hotplug.subfs.functions (i.e. deleted 'sync' from the mounting line there) and after that all worked fine. But in SUSE 9.3 (which I currently use) no matter what I change in /etc/hotplug/hotplug.subfs.functions, the USB disk is always mounted 'sync' (with that horrible writing performance). I understand that it's got something to do wit HAL, but I desperately need to mount the USB disk without sync. Can anyone tell me how to do that? (or even better - how to make sync mounted usb disk write faster than 2MB/s?)
Thank you very much in advance
Jan Romportl
Jan, You definitely don't want to disable sync. Instead, you want to set the "commit" interval to something less frequent. The default is that sync happens every five seconds. You'll need to edit /etc/hotplug/hotplug.subfs.functions to insert, say, "commit=15" to let the disk sync every 15 seconds. Have a look at the line in /etc/hotplug/hotplug.subfs.functions below 'case "$fstype" in' (line #247 in my version of that file)-- this is where "sync" is inserted into what becomes /etc/fstab (from what I can see from a casual browse of that file). I'm thinking you probably want to add a line to the case statement to single out just your (slow running) external drive. Of course it would be wise to test out various commit intervals manually first, before setting it into code. Happy hacking! hth, ken -- A lot of us are working harder than we want, at things we don't like to do. Why? ...In order to afford the sort of existence we don't care to live. -- Bradford Angier