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 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
Try replacing sync with async, see "man mount". Regards Sid. -- Sid Boyce ... Hamradio License G3VBV, Keen licensed Private Pilot Retired IBM Mainframes and Sun Servers Tech Support Specialist Microsoft Windows Free Zone - Linux for all Computing Tasks
I find that I get a lot better performance by finding the device that the usb will mount. I have added the following items in my fstab /dev/sdc1 /media/cfc auto user,noauto,rw,exec 0 0 /dev/sdd1 /media/smc auto user,noauto,rw,exec 0 0 /dev/sde1 /media/msc auto user,noauto,rw,exec 0 0 /dev/sdf1 /media/mmc auto user,noauto,rw,exec 0 0 /dev/sdc1 /media/backup auto user,noauto,rw,exec 0 0 Created the appropriate directories in /media I can get my disk drive to perate between 20 to 25MBytes per second after I mount the drive to the appropriate mounts. Sid Boyce wrote:
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
Try replacing sync with async, see "man mount". Regards Sid.
-- Joseph Loo jloo@acm.org
The Monday 2005-05-23 at 11:52 +0200, Jan Romportl wrote:
'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?)
Read the thread pertaining to this email: X-Message-Number-for-archive: 236165 Date: Fri, 13 May 2005 16:12:51 +0200 (CEST) From: Carlos E. R. To: SLE <suse-linux-e@suse.com> Subject: Re: [SLE] automounting of Floppy 9.3 [solved: NOT automounting] http://lists.suse.com/archive/suse-linux-e/2005-May/1952.html It is not exactly what you are looking for, but it will give you ideas where to place the changes. I don't have one of those external disks, so I can not be more explicit. -- Cheers, Carlos Robinson
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 "$fstype" in' (line #247 in my version of that file)-- this is where "sync" is inserted into what becomes /etc/fstab (from what I can see from a casual browse of that file). I'm thinking you probably want to add a line to the case statement to single out just your (slow running) external drive. Of course it would be wise to test out various commit intervals manually first, before setting it into code. Happy hacking! hth, ken -- A lot of us are working harder than we want, at things we don't like to do. Why? ...In order to afford the sort of existence we don't care to live. -- Bradford Angier
Ken, Jan, On Tuesday 24 May 2005 03:25, ken wrote:
...
Jan,
You definitely don't want to disable sync. Instead, you want to set the "commit" interval to something less frequent. The default is that sync happens every five seconds.
I think you're mistaken about what these options mean. Synchronous writing (the "sync" option) means that data written by a program is not retained (solely) in the kernel buffer at all, but is immediately written to the destination disk when the application issues a write(2) system call. This is what makes it safe to disconnect removable media such as flash RAM disk emulators immediately after the program(s) that write to them complete. On the other hand, the periodic "sync" performed by the sync daemon process(es) only affects files system volumes _not_ mounted with the sync option.
You'll need to edit /etc/hotplug/hotplug.subfs.functions to insert, say, "commit=15" to let the disk sync every 15 seconds. Have a look at the line in /etc/hotplug/hotplug.subfs.functions below 'case "$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).
If the device is mounted with the "sync" option, the "commit=interval" option is irrelevant.
...
hth, ken
Randall Schulz
participants (6)
-
Carlos E. R. -
Jan Romportl -
Joseph Loo -
ken -
Randall R Schulz -
Sid Boyce