usb disks?? Automounting on /media once, slow writing

Michal Jaegermann michal at
Sun May 22 21:25:30 UTC 2005

On Sun, May 22, 2005 at 10:08:21PM +0200, René van Paassen wrote:
> Inserted a usb 2.0 disk, and the thing duly shows up on /media/usbdisk
> However, writing was painfully slow, order of 100 kB/s

That is most likely because hal is mounting removable USB devices
with 'sync' option.  Personally I think that this is insane and
will cause numerous complaints and claims that Linux is extremely
slow but this is supposed to be "idiot-proof".

Mounting sync is really bad for a writing speed, and likely quite
bad for "USB sticks" even if they do "wear levelling" in a
reasonable way, but gives you a fighting chance that you did not
screwed up your data and/or a file system on that device if you
pulled it out without unmounting first.  Mind you - only a chance
and very far from guarantees.  Of course if you will kill your USB
memory stick in the process this is not much of a gain.

There is some possibility that you can change that policy on your
machine if you will be able to figure out how - which is hard to
call "documented".

> Tried a second disk, this one would not automount. After manually
> mounting it (/dev/sde1) it ran well, with normal writing speed. 

A default for mount is 'async' so you will see what you see unless
you asked otherwise.

> Inserted the original disk again, and would not automount. After manual
> mount (/dev/sde this time) it also ran well. 

I guess that this is the same issue.  Maybe even the same as 156167
but I really do not know.


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