persistent store creation freezes at 96%

[rwcitek]

I found that whether I tried creating the image file in-place on my USB memory stick, or tried to copy the 32M file onto it from my HD, it sat there interminably trying to sync all of the information out.

What you describe suggests that the problem is not with the script that creates the image but rather with the USB device. Perhaps its using USB1.1, although even at 12 Mbps, copying should only take about 30 seconds. Can someone stick in a USB stick and try a simple write test? For example:

mount /mnt/uba1
cd /mnt/uba1/
file.test () { dd if=/dev/zero of=foo.usb.test bs=1k count=$1 ; sync; }
sync
time -p file.test 10
sync
time -p file.test 100
sync
time -p file.test 1000

What were the results?

Regards,
- Robert
http://www.cwelug.org/~rwcitek

[rwcitek]

Can someone stick in a USB stick and try a simple write test?

Had a spare moment to fire up Knoppix and test the USB write performance:

root@2[uba1]# rw.test () { dd if=/dev/zero of=rw.test.$$ bs=1k count=$1 ; sync ; }
root@2[uba1]# sync ; time -p rw.test 10
10+0 records in
10+0 records out
10240 bytes transferred in 0.000254 seconds (40302038 bytes/sec)
real 0.65
user 0.00
sys 0.00
root@2[uba1]# sync ; time -p rw.test 100
100+0 records in
100+0 records out
102400 bytes transferred in 0.000894 seconds (114545258 bytes/sec)
real 1.29
user 0.00
sys 0.00
root@2[uba1]# sync ; time -p rw.test 1000
1000+0 records in
1000+0 records out
1024000 bytes transferred in 0.017315 seconds (59139134 bytes/sec)
real 9.70
user 0.00
sys 0.02

1 MB/ 10 sec = 0.1 MB/sec
So, 256 MB would take about 40 minutes. That is indeed a long time.

Regards,
- Robert
http://www.cwelug.org/~rwcitek