UMS speed slowdown by factor 20!?

expose · n00b Joined: 13 Feb 2004 Posts: 13

Hi guys.

my usbstick seems to work fine. i cant see any error messages or anything, but still it just reaches 8 to 16kB/s while it did more than 200 a few days ago.
if you have any idea of what could cause this, a setting i'm not aware of, please tell me :-)

What i found out is that it seems to be still somewhat faster when i run it not with "sync" as a mount option. so, i copied on file with "sync" and mc said the ETA would be 5 minutes, and things went on slow. when i tried the same and unmounted it, the "umount" process was finished within half a minute or so, which would be normal.

But i cannot see a reason for such a behaviour, and anyway i would like to run the stick "sync"ed so i can remove it without the need to wait for umount to finish.

it also doesnt matter if i'm root or not. a small output by dmesg concerning the stick is:

aries · Posted: Fri Jul 29, 2005 6:37 pm Post subject:

Hi Daniel,

Iám afraid I can help you: I have the same problem:
- the device is automounted under KDE at /media
- some weeks ago downloading with normal USB 1.1 speed
- now about 20kb/s

maybe it has to do with a kernel update

expose · n00b Joined: 13 Feb 2004 Posts: 13

aries · Posted: Mon Aug 15, 2005 3:38 pm Post subject:

Hello!

I'm back, sorry for my late answer but last two weeks I was in France for holiday.

The slowdown is caused by the kernel, with kernel 2.6.11 the write speed is > 800k/s.
These links give an explanation
http://bugme.osdl.org/show_bug.cgi?id=4882 and http://www.spinics.net/lists/usb/msg04174.html

The thing that worked was to change manually fstab:

aries · Posted: Mon Aug 15, 2005 7:02 pm Post subject:

Hi,

An addition to the previous message:
I switched to fstab-sync instead of pmount and changed the file /usr/share/hal/fdi/90defaultpolicy/storage-policy.fdi

expose · n00b Joined: 13 Feb 2004 Posts: 13

Thanks!

Will read it after i got some sleep, although i currently cant test it anyway - my machine is broken

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

And, note (if not noted already) that with the sync option, you will destroy your USB-flash drive with one large file. Click.

Edit:
BTW, you shouldn't change the default policy, because it will be overridden when hal is updated. The proper place to put it, is in /usr/share/hal/fdi/95userpolicy/ (although, the newer versions of HAL (0.5 or something) use /usr/share/hal/fdi/policy/20thirdparty. And, for those versions, this fix would seem to be unnecessary. Check if you insert a device, if "sync" is part of the mount options (with mount). If not, this fix should not be needed). Create a file name (like storage-policy.fdi), and put this in it:

Tarball · Posted: Sun Sep 11, 2005 9:41 pm Post subject:

I have found this problem myself.

I have added a hal fdi file to mount USB VFAT devices without sync option.

However, I now need to allow users to mount/umount so the device can be unmounted to maintain data integrity, as the first-post stated without sync option I guess it is dodgy for the user to just pull the device.

I haved played around with the setting but I can't get hal/ivman to mount the device with the 'users' option to no avail.

Anyone solved this?

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

Is your problem that the "users" options is not enabled in the fstab, or that ivman mounts it as root? I get the "users" option in fstab, I didn't need to do anything for it. As for ivman, I don't use it. KDE mounts it automaticly by going to media:/.

However, browsing through this media:/ errors somewhat on Konquerer. It insists on using big icons, I have to set it back to detailed view all the time. It's very annoying. And there were some problems with playing some movies from cd or whatever from the media:/ handle. For some movies, I have to go to /media/cd* manually and open it.

Matteo Azzali · Retired Dev Joined: 23 Sep 2004 Posts: 1133

I have the same issue, but I don't use ivman, pmount nor anything except
KDE media:// directory (I'm using the same storage policy of ivman)......
storage-policy.fdi "removing removable sync option"
should works, but what if I unplug the flash drive (for error) whitout unmounting???

(p.s: kernel 2.6.13 , speed below 80kb/sec with sync option)

@halfgaar : could you please post (here, pm) your /etc/fstab (cdroms and usb only)
and hal storage-policy.fdi ? Thank you.
_________________
Every day a new distro comes to birth. Every day a distro "eats" another.
If you're born distro, no matter what, start to run.
---- http://www.linuxprinting.org/ ---- http://tuxmobil.org/

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

HAL puts the following two lines for my cdroms in fstab:

Matteo Azzali · Retired Dev Joined: 23 Sep 2004 Posts: 1133

OK, I was thinking to use the ivman recommended storage policy modified only for the sync, but that was givin troubles
(mounting bad, as msdos partition). Also I was thinking (I was wrong) some line in /etc/fstab was needed.
Changed the 95.../storage-policy.fdi, removed any line for usb from fstab, working like a charm.
_________________
Every day a new distro comes to birth. Every day a distro "eats" another.
If you're born distro, no matter what, start to run.
---- http://www.linuxprinting.org/ ---- http://tuxmobil.org/

Gentree · Posted: Sat Feb 11, 2006 1:05 am Post subject:

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

Matteo Azzali · Retired Dev Joined: 23 Sep 2004 Posts: 1133

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

I don't want to turn this into a KDE discussion, but I have to say one more thing: most things don't work in KDE

. Kmail is unusable for me because of bugs, Kopete doesn't show type notifcations with Jabber, Koquerer has some annoying bugs, Korn (shows popup for new mails) often displays empty popup instead one with sender and subject, Kooka (scan tool) is unusable because of bugs. What I mean by this is, that KDE is far from stable...

Gentree · Posted: Sat Feb 11, 2006 8:06 pm Post subject:

I relayed this info to a mate who installed suse 10 for his daughter with a USB device for large daily backups!

Looks like I got there in time, at least to save some of the life of her stick. So many thanks.

He reports that with sync a large file copy on suse was about half the speed of the same copy on XP. Now it's nearly 4x faster!

I dont use hal on gentoo so it's a bit second-hand but it appears that hal-subfs mounts and unmounts the usb device on demand so the sync is completely unnecessary anyway.

Can you comfirm that is the case ?

_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86

Matteo Azzali · Retired Dev Joined: 23 Sep 2004 Posts: 1133

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

Gentree · Posted: Sun Feb 12, 2006 2:47 pm Post subject:

Do you know the orgin of the sync default? Is it KDE dumbing down the user or is this part of a default hal config.

In either case I think every distro needs to correct this a.s.a.p as a local patch until a permament correction trickles down from "upstream".

Having determined the package responcible a critiical bug report should probably be opened on gentoo.

Thanks again for bringing this to our attention.

_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

Gentree · Posted: Sun Feb 12, 2006 3:36 pm Post subject:

Well I agree a bit about the buck passing , I was reading some the thread on LKML that you posted and I see Alan Cox blaming it on "shite" flash devices. Like "good" put up with shite threatment, only cheap ones get burntout :roll:

There is damn sure a documentation bug since it says the opposite to what happens.

In other respects vfat is non journalling and if you ask for it to be mounted in sync mode it may be necessary to hammer the FAT to comply with that demand. Maybe an intermediate defered syncing policy could be invented to deal with this.

The apparent change around 2.6.12 is , in fact , what makes this relevant, since before that it made no difference to usb devices formatted as vfat since the kernel ignored it.(It could be argued that it was there for iPods with original HFS format).

Now I am aware that it's hal which is doing the job here, my previous question was whether sync for usb was hal defaults or something added by KDE to make it more "user-friendly" .

_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

(I edited my above post at the same time you posted, so you may have missed some)

Gentree · Posted: Sun Feb 12, 2006 4:20 pm Post subject:

I was refering to you post here linking to the LKML thread. My comment about the doc was taken from the original post in that thread . I assume it has now been corrected since this is about nine months old.

The fault seems to be that there was a small but critical change in kernel policy that was quietly slipped in around 2.6.12 like no-one thought it was that important. Turns out it is.

Since pre 2.6.12 ignores this option for fat32, I'm not sure why the rule is in there in the first place.

The fact that it did nothing may explain why it was never picked up in testing by hal.

To me it looks like a series of compounded minor errors, a default in communication/documentation in distributed development.

_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands