USB Booting - differences in usb flash drives

Forum: USB booting
Topic: USB Booting - differences in usb flash drives
started by: traveling17

Posted by traveling17 on Oct. 16 2006,17:58

Hi and thanks for any thoughts to this curious inquiry. I have two usb flash drives - a sandisk titanium 2Gb and a sandisk cruzer micro 512 Mb. I follow the directions of formating the drives and unzipping the dsl zip onto the flash drives. I then run the syslinux commands. I go to my test computer and put one of the flash drives in, set the bios to boot to either usb-hdd, cdrom (no cdrom in the drive but used it to test cd iso), or usb-zip and turn it on. If the test computer boots to the 2Gb sandisk then everything functions correctly. If the test computer boots to the 512 Mb sandisk then it stops during the usb scanning and then errors with Can't find knoppix system. I have tried reformating the drive, reinstalling the dsl, and running the syslinux multiple times. The 2Gb flash drive was recently purchased and advertised to be faster than normal usb flash drives. However, both sandisk drives show on their website as usb 2.0 certified. Also, note that I tried to use the waitusb as well as the toram cheatcodes with no sucess. So what could be the differences between the two to cause one to work and the other to not work. The only difference I see is the size of the drive. Has anyone had similar issues? Any ideas? It is not a big thing since I got it working on the 2gb. Just curious!

Thanks!

Posted by pmisch on Oct. 17 2006,08:38

Hi,

Sandisk cruzer is perfectly able to USB-booting.
I am using it daily with DSL and my Damn Small Machine.

But: The stick should be FORMATTED correctly and this
is not always the case.

Rules for USB-ZIP-compatibility:
32 tracks / sectors and 32 or 64 heads.

LOOK HERE ->
< http://www.damnsmalllinux.org/wiki....endrive >

For me this worked on nearly all of my USB-Sticks
(at the moment I'm testing 9 different ones ;-)

Peter

Posted by traveling17 on Oct. 17 2006,21:08

Aha Cheers Mate! I slightly followed the directions from the link you sent and got it working. I copied the dsl to cd and boot it up from the cd. I then tried running the sfdisk commands on the usb and probably created the wrong calculations. I got to the part that says run the mk2fs but the dsl didn't have this command or a man page on it. So I decided to try the pen drive install from the dsl tools which I had done in the past without sucess. This time it worked. The past failed times might be due to the HP formatting tool I was using. DSL might have read the format and tried to install it on the formated usb. Since I wiped out the format and changed up the heads, cylinders, and sectors the install saw it as messed up and fixed it for me because I checked the sfdisk before and after the install of the pen drive and they were very different. So now both sandisk usb's work!

Thanks for the help!

Posted by pmisch on Oct. 19 2006,20:50

Hi,

Well, thats fine ...

My experience with USB-Booting :

One has to be careful when using
a Formatting Tool like this HP-tool.
Sometimes it works very well together
with Windows but not with Linux.
Reason: In a stick there seems to exist
a table with fixed predefined factory
partioning values. These values
are used by the HP-tool
to partition and format your stick.

But these values are not appropriate
for booting the PC from the USB-stick.
Some BIOS' prefer a ZIP-like
partioning-structure.
that means: 32 tracks / sector
a multiple of 32 heads, and
less than 1024 cyls.

What to do:
The stick has no such hardware parts
like a harddisk - we can change the partioning
values. So bypass the internal partition table
and create one by yourself. This is simple with
Linux, not so with Windows.

3 ways:

- /usr/sbin/pendrive_usbzip.sh
This script will do it al lperfectly ...

- /sbin/sfdisk - repartition the stick with 32 t/s
and 32 or 64 heads. In most cases (95%) this will
make the flash-stick bootable.

- /bin/mkdiskimage -1 /dev/sdb1 yyy 64 32
where yyy is the capacity of the stick (MB).
Avoid more than 1024 cyls (your 2GB-stick).
Its better to create two smaller filesystems.

In the latter cases we have to create the filesystem
and copy the data by ourself. But thats rather
easy with DSL.
Don't forget to use > syslinux /dev/sdb1 !

DSL is my favorite linux :-)

Good luck....

Peter