Flash to USB installer (experimental) in 7.0.5

[STraute]

Hello ttopp

Good Morning, Thanks for the response. I don't understand it yet but I will read it slow, today. I am sorry for the re-formatting someone (Administrator) is doing to make this readable so have taken to just a 'reply' rather than 'with quote'. I will go back to the faqs and see where what and how to post properly.

I am sure it will suit Mr. Werner P. Schulz if he sees posts from You not needing reformatting.
So You may refrain from including quotes - Just mention what You are replying to.

You may ask for clarifications if You want to.

[ttopp]

That was fun. I actually saw the searching of the iso image for KNOPPIX. I first booted using the dvd. then in a terminal window I typed sudo fdisk -l (list) and found this for both 64gb and 16gb usb drives.

Disk /dev/sdd: 62.8 GB, 62813896704 bytes
64 heads, 32 sectors/track, 59904 cylinders, total 122683392 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdd1 * 1 81631231 40815615+ c W95 FAT32 (LBA)
/dev/sdd2 81631232 122683391 20526080 83 Linux
knoppix@Microknoppix:~$

Disk /dev/sdd: 16.0 GB, 16008609792 bytes
64 heads, 32 sectors/track, 15267 cylinders, total 31266816 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/sdd1 * 1 8433663 4216831+ c W95 FAT32 (LBA)
/dev/sdd2 8433664 31266815 11416576 83 Linux
knoppix@Microknoppix:~$

I then booted with the dvd and at the knoppix penguin I typed knoppix bootfrom=/dev/sdd1/KNOPPIX/KNOPPIX and here is where it says, searching ISO for KNOPPIX ?

[STraute]

Hello ttopp

I then booted with the dvd and at the knoppix penguin I typed knoppix bootfrom=/dev/sdd1/KNOPPIX/KNOPPIX and here is where it says, searching ISO for KNOPPIX ?

What did happen after the searching? Did it just hang there? Nothing?

For both USB flash devices, I would expect the boot loader from the DVD to mount the partition image file from the flash storage and to continue booting to the Knoppix desktop, but without mounting the persistent overlayfile system on /dev/sdd2. Did that work?

[ttopp]

Hello ttopp

What did happen after the searching? Did it just hang there? Nothing?

For both USB flash devices, I would expect the boot loader from the DVD to mount the partition image file from the flash storage and to continue booting to the Knoppix desktop, but without mounting the persistent overlayfile system on /dev/sdd2. Did that work?

Good Morning. I read your response and clicked reply with quote and I am now typing below your answer. I hope this is the proper way. OK. Yesterday the message was can not find KNOPPIX dir in ISO and it kept cycling through the available areas. This morning I used the 8GB after seeing it has only 1 area, sdd1. Same message and kept cycling. But now I will try again and I will WAIT... to see what it does if it does continue... Thank you. Siddhartha can wait. So can I.

[ttopp]

Good Morning. I read your response and clicked reply with quote and I am now typing below your answer. I hope this is the proper way. OK. Yesterday the message was can not find KNOPPIX dir in ISO and it kept cycling through the available areas. This morning I used the 8GB after seeing it has only 1 area, sdd1. Same message and kept cycling. But now I will try again and I will WAIT... to see what it does if it does continue... Thank you. Siddhartha can wait. So can I.

OK. After 28 cycles PC booted to the DVD. As it cycled I tried to see the different messages and noticed a mnt-iso in the text that went by. There is a note after my post that mentions boot hd is that for me to try? Thanks.

[ttopp]

Hurrah Hurrah Hurrah! It worked! knoppix fromhd=/dev/sdd1 Thanks people, - you're the best.

[STraute]

Flash devices onto which ttop had written Knoppix 7.0.5 (both using the experimental installer "flash-knoppix2" and the "traditional" installer) were directly bootable (as USB block storage devices) on some PCs, but not on the main PC of ttop. He could not resolve this via BIOS setup changes.

I had suggested to him (as a Test) to try to boot from a Knoppix CD or DVD; And at the kernel prompt to enter a cheat code in order to mount the compressed read-only file system image in file KNOPPIX/KNOPPIX from the flash device (instead of the copy on the optical medium). The cheat code "knoppix fromhd=/dev/sdX1" does this (not "bootfrom=", as I had wrongly suggested before). ttop replied that this had solved his Knoppix booting problems, which was a suprise for me:

Hurrah Hurrah Hurrah! It worked! knoppix fromhd=/dev/sdd1

Then it occured to me to try this scenario myself, in order to learn what had happened on the PC of ttop. My PC can boot from USB, but I tried to boot from a DVD with Knoppix 7.0.5, while a SDHC memory card with Knoppix 7.0.5 was already inserted/connected. At the kernel/boot prompt I entered the cheat code: knoppix fromhd=/dev/sdb1 . To my suprise, not only did Knoppix continue loading from my SDHC card, but it also had the persistent overlay reiserfs filesystem from the SDHC card mounted. This means one can work with a read-write Knoppix system started from a flash storage device even on PCs which are unable to boot from USB devices! (Provided the PC has a DVD drive and one brings a Knoppix DVD, too.)

To further my (at this point clearly broken) understanding of the Knoppix boot process, I decided to investigate: Like most Linux systems nowadays, the Knoppix kernel first passes control to configuration software (which for example might supplement the kernel with kernel modules for support of the present hardware) before initialising the system services (by using SysV init scripts or upstart or...). The kernel modules and configuration software can be found in a special compressed archieve/file system image file, which gets loaded and used directly after the kernel has finished loading. I have unpacked this file system using these commands:

cd
mkdir minirt
cd minirt
gzip -dc /mnt-system/boot/syslinux/minirt.gz | cpio -idv 2>minirt_cpio_errors.log

The cpio command will try to unpack even the special files in the /dev directory of this file system, but this will fail and cause error messages because user knoppix does not have the needed permissions to invoke mknod to create the special files.

Anyway, after this I could read the system configuration script using this:

 less init

This shell script implements the support for most of the Knoppix cheat codes. The version on the Knoppix 7.0.5 DVD images not only identifies a storage device from which the file system image in file KNOPPIX/KNOPPIX can be mounted, it also looks for a second partition on the same device from which an overlay file system can be mounted (as /KNOPPIX-DATA) for persistent storage (among many other measures). It will not find such a partition on a DVD or CD (No partitioning, therefore no second partition), but if directed to another storage medium using the "fromhd=" cheat code, then the script does find it there and mounts it. This behavior is flexible and very useful!