Damn Small Linux - Not!

Juanito · Joined: 11 Sep 2006 Posts: 88 Location: Dubai, U.A.E.

Apologies if this is repeated in the forum but I did not see anything on this for RC4.

I can boot DSL-N from CD without problems (apart from the display issues due to the Intel 82852/855GM Integrated Graphics Chip which I presume can be cured with XFree86).

If I try to boot from a 1GB Sony Micro Vault stick written as USB-HDD (which appears as device sda) then I get a blank screen and "boot error". I can boot DSL 3.0.1 from the same stick although with the following error:

INIT: Entering run level: 5
Invalid device sdb1
Press enter to continue [then everything is OK]

Note that to over-write the USB stick, I booted DSL 3.0.1 from another USB stick (device sda1) and wrote the new USB-HDD to device sdb.

It is possible that the "sdb1" error is due to the way in which DSL-N formatted the stick originally?

Juanito · Joined: 11 Sep 2006 Posts: 88 Location: Dubai, U.A.E.

After reading the post on partitioning USB sticks and the limits of <1024 cylinders and <= 32 sectors/track for a boot partition, I copied DSL-N RC4 from the "non-bootable" USB stick to ramdisk and re-partitioned the USB stick.

I now have two partitions, a boot partition of 250 cylinders, 32 heads and 32 sectors/track of +/- 128MB (sda1) and a second partition (sda2) with the balance of the 1GB stick.

I "syslinux"-ed the boot partition and copied DSL-N back from ramdisk to the boot partition.

I can now boot DSL-N from the 1GB USB stick but for some reason I cannot access sda1 once booted - I get an error message that mtab has it mounted as device cdrom...

Since creating a bootable USB-HDD from the DSL-N CD creates a single partition of 1023 cylinders, 32 heads but 62 sectors/track (on a 1GB USB stick) - it looks like it is the 62 sectors/track that is preventing DSL-N from booting from USB.

Does anyone have any ideas how to fix the "sda1 mounted as crdom" error?

roberts · Joined: 17 Apr 2006 Posts: 320 Location: OC CA USA

I believe the change to the geometry of a pendrive is only required of the usb zip boot style.

Both DSL and DSL-N format the pendrives the same.

I don't have any very large pendrives to test?

Could this be a limitation of fat and syslinux?
Possibly use the latest syslinux?

Juanito · Joined: 11 Sep 2006 Posts: 88 Location: Dubai, U.A.E.

I tried a couple of times to create a bootable USB-HDD from the DSL-N desktop menu and both times it failed.

As soon as I re-partitioned the stick as per the previous post and manually copied the DSL-N boot files, everything worked - this would tend to indicate that the change of geometry is required for both ZIP and HDD type USB sticks.

Note that with my 1GB USB stick, 250 cylinders = 128MB, so I presume I could use up to a 512MB stick (1000 cylinders, limit = 1023 cylinders) before running into the boot problem.

A couple of questions:

1. Will DSL-N boot from a linux formated USB-HDD (type=83) rather than a FAT16 (type=6)?
2. What is the latest version of syslinux that will work with DSL-N?
3. Is sda1 intended to be mounted as cdrom in DSL-N - this doesn't happen with DSL?

Juanito · Joined: 11 Sep 2006 Posts: 88 Location: Dubai, U.A.E.

I worked on this issue some more and found that after formatting the entire 1GB USB stick as one FAT32 partition and using syslinux 3.2 to write the ldlinux.sys boot file, I could boot DSL-N 0.1RC4.

There is a problem however in that DSL-N thinks it has booted from a CD - usually the USB stick boot partition would be mounted as /mnt/sda1 but in this case it is mounted as /cdrom (not /mnt/cdrom).

If I try to mount /mnt/sda1, I get the message that it is busy. In addition, the files in backup.tar.gz are not restored and the *.dsl files in the boot partition are not loaded on start-up.

Note that in order to create a bootable DSL-N USB-HDD, I first booted from a CD and used the desktop menu to create a bootable USB-HDD. I then copied the files from the USB stick to /ramdisk, reformatted the USB stick as FAT32, applied syslinux and then copied the original files (except ldlinux.sys) back from /ramdisk.

Maybe the solution to my problem is to modify the USB-HDD desktop menu script to create a FAT32 partition instead of FAT16, where do I find this script?

Is there something else I can modify on the USB stick to prevent DSL-N from treating it as a CD-ROM?

Juanito · Joined: 11 Sep 2006 Posts: 88 Location: Dubai, U.A.E.

I seem to be running my own private post here but anyway... Laughing

To summarise my findings on booting DSL-N 0.1RC4 and DSL 3.0.1 from USB-HDD memory sticks:

1. The RC4 "create pendrive USB-HDD" script (pendrive_usbhdd.sh) will create a single FAT16 partition on any size of memory stick up to 1GB (the largest capacity USB stick I have). [b]RC4 will not boot from this USB memory stick if its capacity is greater than +/- 512MB[/b].

2. The 3.0.1 "create pendrive USB-HDD" script will create a single FAT16 partition on any size of memory stick up to 1GB (the largest capacity USB stick I have). [b]3.0.1 will boot from this USB memory stick.[/b]

3. Using the memory stick created by DSL 3.0.1 in 2 above - if all of the files (except ldlinux.sys) are deleted and the appropriate RC4 files (except ldlinux.sys) copied onto the memory stick, then RC4 will boot from a USB memory stick of up to 1GB.

4. If a single FAT32 partition is created under Windows and syslinux 3.2 used to create ldlinux.sys under Windows, then RC4 will boot from a USB memory stick of up to at least 1GB (the largest capacity USB stick I have).

5. If two FAT16 partitions or two FAT32 partitions are created under RC4, the syslinux suppied with RC4 will not write ldlinux.sys - it reports the error "Total number of sectors not a multiple of sectors per track!". After using syslinux 3.2 under Windows (which does not report any errors), RC4 will boot from this USB memory stick.

[b]Points 1-5 would tend to indicate that the version of syslinux supplied with RC4 is creating the failure to boot from a USB memory stick larger than +/-512MB.[/b]

6. Even if the "frugal" boot option is used for booting from a USB memory stick under RC4, /mnt/sda1 will be seen by RC4 as "busy" during the boot process and thus restore and dsl extensions will not work. This does not happen when booting a USB memory stick under DSL 3.0.1.

[b]Note that in RC4 all of the directories/files on the first partition of a USB memory stick are mounted as /cdrom, in 3.0.1 only the directory /knoppix is mounted as /cdrom.[/b]

7. If two partitions are created on a USB memory stick, then restore and dsl extensions will work under RC4 during the boot process as long as they are on the second (/mnt/sda2) partition.

Note that DOS/Windows can only access a single (the first) partition on removeable media so anything on /mnt/sda2 is inaccessible to DOS/Windows.

Given the above observations, [b]would it be possible to change the DSL-N syslinux version to that of DSL 3.0.1 and mount only /knoppix as /cdrom under RC5?[/b] This would allow DSL-N to be booted from a single, large partition on a USB memory stick that would still remain fully readable under DOS/Windows.

roberts · Joined: 17 Apr 2006 Posts: 320 Location: OC CA USA

I will compare the syslinux versions.
I have no way to test. My largest stick is 512.

Juanito · Joined: 11 Sep 2006 Posts: 88 Location: Dubai, U.A.E.

Thanks.

Is there a way to stop DSL-N mounting all of the files (backup.tar.gz, syslinux.cfg, etc) in the USB memory stick root directory under /cdrom?

This would prevent the error "/mnt/sda1 busy" when DSL-N tries to restore backup.tar.gz, load XFree86.dsl, etc whilst booting.