W dniu 05.09.2012 23:47, Anatoly pisze:
В Tue, 4 Sep 2012 23:55:57 +0400
Anatoly <> пишет:

Hello,
I have a problem with my new 32G pendrive:

da1: <JetFlash Transcend 32GB 8.07> Removable Direct Access SCSI-2
device da1: 40.000MB/s transfers
da1: 30640MB (62750720 512 byte sectors: 255H 63S/T 3906C)

I'm using fat32 partition on it.
To make problem occur I can do following things:
1) write a file about 5MB in size on that partition
2) unmount
3) unplug pendrive (so it loses power)
4) plug it again
5) mount
Now I can see that the end of file is corrupted.

Poblem never occurs when I do:
1) write a file about 5MB in size on that partition
2) unmount
3) mount
Also, problem doesn't occur if I'll wait for more than ~10 minutes
before unplugging pendrive.

So it seems to me that this pendrive has internal write cache in RAM
that needs to be flushed before pendrive loses power.
Problem never occurs with Windows. As I click "remove", windows
somehow "correctly shutdowns" pendrive so it's LED goes off (Unlike
if i just unmount, when the LED stays on)

What can I do to get cache flushed before unpugging, turn that write
cache off, or any other suggestions?
I've tried camcontrol stop and camcontrol eject with no
success
I using FreeBSD 7.3 with generic kernel here
I've found solution:
http://lists.freebsd.org/pipermail/freebsd-usb/2008-March/004677.html
that 'upower' utility allows to suspend pendrive, and I get cache
flushed (And LED goes off):
upower /dev/usb0 2 suspend
_______________________________________________
freebsd-usb@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-usb
To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"

To flush cache You can also use sync(8)


Stanislaw.
_______________________________________________
freebsd-usb@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-usb
To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"

Reply via email to