re: USB (flash or hd) install - Why can't ext2 or ext3 FS be

[stevesr0]

I am unclear why an install to a USB device (flash or HD) requires the drive to be formatted as a FAT FS rather than a native Linux type.

Appreciate the reason for this.

Thanks

Steve

[stevesr0]

I am puzzled by the need to use a vfat filesystem for a linux install.

I want to do a USB install of 6.2.1 and just boot from the usb.

My BIOS allows booting from USB, so I am unclear why vfat is required, rather than using ext2 or ext3.

I have searched for answers on the web and have drawn a blank.

If one has a Linux install as the only OS on a hard drive, we obviously expect to be able to boot it without making a vfat partition (or am I showing my gross ignorance).

Thanks in advance.

Steve

[stevesr0]

Well, I finally thought to look at the SYSLINUX project and apparently the reason why a vFat partition type is required is because that's what SYSLINUX uses.

However, the project also provides a similar bootloader designed for ext2/ext3 partition types.

So, my question is - has anyone substituted EXTLINUX for SYSLINUX in their USB install in order to obtain support for ext2/ext3 as the bootable partition (or do people simply use a big enough USB stick to make a second partition of ext2/3 type?)

Steve

[Capricorny]

No, you don't have to boot off a FAT32 partition to run Knoppix. I have posted one simple example of using GRUB here, so you don't really have to go into the syslinux FAT32-booting stuff at all.
I think that way is much simpler than making a version with ext2/3 syslinux, but you must have a way of installing GRUB. I just used an existing HD install, Mandriva, but it could really be just about any distro.

Because Knoppix consists of 1+ loop/cloop-mounted image files, with ext2 file systems on them, what kind of file system those files are installed on doesn't really matter much. To me, it seems rather irrelevant. There are several good reasons for keeping them on a partition distinct from ordinary Unix user data, and there is hardly one very good reason for mixing. The space requirements are fixed at setup time, so you don't have to waste a lot of space on a FAT32 partition. Typically, you could set up a 16 GB stick with an 8.5GB FAT32 for the DVD cloop KNOPPIX image and persistent user data, and a 7.5 GB ext3 for the "rest". You could make the ext3 partition bootable, install GRUB and boot the KNOPPIX image from there. GRUB's space requirements are modest.

There is another very good reason for operating with more than one partition: With the present setup, there can be at most on KNOPPIX structure per partition, and there are many reasons to be able to have several KNOPPIX versions available. For example, the new bugs introduced with a new release might force you to have an older version available.

[stevesr0]

I just used the TinyCoreLinux USB installer which allows an ext format only partition as an option.

Since I was only interested in booting one OS from the flash drive, I didn't need grub at all.

The auto install program uses the syslinux program designed for linux formats (extlinux).

So, I guess (??) that knoppix could be installed to a bootable USB flash drive without a FATformatted partition.

Steve

[Capricorny]

....
Since I was only interested in booting one OS from the flash drive, I didn't need grub at all.
....
So, I guess (??) that knoppix could be installed to a bootable USB flash drive without a FATformatted partition.

You have already the answer: Yes, and in several ways. GRUB is fine also with just one OS to boot. The extX vs of syslinux is surely also very OK, but I can't see why not just use GRUB when you have an adequate file system installed. Syslinux is kind of "poor man's boot" to me, and the greater generality of GRUB doesn't really add to the complexity in use, cfr the way I boot my everyday Knoppix install with GRUB. As far as I have understood, the FAT32 requirement is because of syslinux - and if it isn't, that should surely be fixed ASAP.

Perhaps a sensible thing to do, is to provide two options for installling Knoppix to flash: The FAT32 way, with syslinux, and a linux fs way, which I would prefer to use GRUB. It is both a principal and practical thing for me: Why not use a universal loader when it doesn't cost more? And practically: One less bootloader to learn about. But there may be command line restrictions with GRUB - think there should be a way around them, though,

It would be interesting if you could make a comparison between the "extlinux" and GRUB approaches.