Re: usb2 port gets very slow on 2-gig Flash Drive.

Say your flash disk is /dev/sdc and has 1 FAT partition where the
music is stored:

cd ~
dd if=/dev/sdc1 of=zenstone2g.img bs=64M
mkdir /mnt/zenstoneimg
mount -o loop -t msds zenstone2g.img /mnt/zenstoneimg
---delete anything in /mnt/zenstoneimg/music you don't want -----
cp -R /path/to/my/music/* /mnt/zenstoneimg/music/
umount /mnt/zenstoneimg
dd if=zenstone2g.img of=/dev/sdc1 bs=64M

You'd only need to run the commands before "mount" once, then keep the
image around for the future.
I don't actually know if this will speed things up, but the idea is
that you are bypassing the filesystem layer over the USB bottleneck
for disk writes.
You make all the filesystem changes to a disk image on your hard disk,
then you stream the bits in that image to the flash disk.
The "bs=64M" is the block size and can be increased or decreased
depending on your situation. AFAIK, it basically acts like a buffer
in situations like this.

Be very careful with the syntax of dd; one misplaced character and you
could wipe your hard disk or flash drive.

Just an idea. Let me know if it works out.

-Elijah

On Thu, Jul 24, 2008 at 8:27 AM, Martin McCormick
<martin@xxxxxxxxxxxxxxxxxx> wrote:
I needed to reload the flash drive on a Zenstone 2-gig mp3
player. I have noticed that when the drive is full, operations
all still work, but take much longer than one might expect which
probably has something to do with the fat32 file system and size
of the FAT table.

I started by doing rm -r -f music which is the one and
only main directory. That took about 2 hours to complete and
then it was time to reload it from the Linux computer.

The Linux computer is a 500-MHZ Pentium running a 2.6.5
kernel and the usb2 port is, by definition 13 Mb so it is slow,
about 10-meg Ethernet slow under normal conditions.

What actually happens is much worse. After doing the rm
-r -f, I started with an empty drive but the tar program started
running very slowly. It takes at times, 10 minutes to load one
tune that would normally play in 2 or 3 minutes.

Just for fun, I let it plod slowly along and it has been
running now for about 36 hours and is 75% complete but what is
happening?

If I look at the health of the system, it isn't that bad
all be it busy.

$ uptime

07:21:58 up 2 days, 23:37, 2 users, load average: 4.00, 4.13, 4.19

It is July 24 and ps ax -Olstart shows me that tar has
been running a very long time:

22986 Tue Jul 22 23:35:01 2008 D pts/13 00:00:40 tar xf /home/martin/musicmain.tar

I tried renic-ing tar and the usb mass storage daemon
which has had no effect, either good or bad.

I do remember once that if there is a time lapse of
several minutes between the rm -r -f command to wipe the FAT
table clean and the tar command that initial performance is much
better so there must be a cleanup routine going on somewhere.

This is also true if you unmount the drive and remount it empty.
I seem to remember that it only took a couple of hours to reload
the entire drive when I did things that way.

I did a top command and I am either missing something or nothing
much is wrong:

Tasks: 42 total, 2 running, 40 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.3% us, 0.0% sy, 0.0% ni, 0.0% id, 99.7% wa, 0.0% hi, 0.0% si
Mem: 126424k total, 124572k used, 1852k free, 1604k buffers
Swap: 377488k total, 0k used, 377488k free, 102308k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
23560 martin 16 0 2160 1084 1880 R 0.3 0.9 0:00.03 top
1 root 16 0 1492 528 1336 S 0.0 0.4 0:07.26 init
2 root 34 19 0 0 0 S 0.0 0.0 0:12.13 ksoftirqd/0
3 root 5 -10 0 0 0 S 0.0 0.0 0:00.00 events/0
4 root 5 -10 0 0 0 S 0.0 0.0 0:04.02 kblockd/0
10 root 7 -10 0 0 0 S 0.0 0.0 0:00.00 aio/0
9 root 15 0 0 0 0 S 0.0 0.0 0:22.06 kswapd0
11 root 25 0 0 0 0 S 0.0 0.0 0:00.00 jfsIO

I plan to let this tar command run its natural course to see
what happens, but is there anything I can do with the existing
system to optimise the performance?

Thanks.

Martin McCormick WB5AGZ Stillwater, OK
Systems Engineer
OSU Information Technology Department Network Operations Group


--
To UNSUBSCRIBE, email to debian-user-REQUEST@xxxxxxxxxxxxxxxx
with a subject of "unsubscribe". Trouble? Contact listmaster@xxxxxxxxxxxxxxxx





--
http://elijahr.blogspot.com/


--
To UNSUBSCRIBE, email to debian-user-REQUEST@xxxxxxxxxxxxxxxx
with a subject of "unsubscribe". Trouble? Contact listmaster@xxxxxxxxxxxxxxxx

Relevant Pages

  • Re: usb2 port gets very slow on 2-gig Flash Drive.
    ... You make all the filesystem changes to a disk image on your hard disk, ... It is July 24 and ps ax -Olstart shows me that tar has ... several minutes between the rm -r -f command to wipe the FAT ... To UNSUBSCRIBE, email to debian-user-REQUEST@xxxxxxxxxxxxxxxx ...
    (Debian-User)
  • tar...? Re: [opensuse] Ideas on disk cloning?)
    ... Is there any easy way to do it from a 13% filled 60GB disk to a remote ... tar'ed filesystem images for installing new machines. ... The "tar" command isn't good to use for cloning, ...
    (SuSE)
  • Re: New HDD Installation
    ... "John John" wrote: ... a single partition disk. ... confirm or change the active flag of the partition using the FDISK command. ... There are other ways to mark the partition active, either with a Windows ...
    (microsoft.public.windowsxp.general)
  • Re: Forgot to put old_rootvg to sleep before reboot - How to Wake
    ... Performs operations on existing alternate rootvg volume groups. ... To rename Alternate Disk Volume Group: ... The alt_rootvg_op command can be used to determine which disk is the ... flag) can be executed at this time. ...
    (comp.unix.aix)
  • PC8477 Demo Program
    ... The PC8477 Demo Program is designed to allow access to all software commands and registers of National Semiconductor's PC8477 Advanced Floppy Disk Controller. ... The left center indicates the number of bytes transferred during the last command issued. ...
    (comp.sys.ibm.ps2.hardware)