Re: Vendor Partitions

[Andrew Clausen]

On Thu, Oct 31, 2002 at 04:06:36AM +0100, Henrik Treadup wrote:
> I will never use parted to create a VP. If I somehow mess up a VP I'll use 
> the Vendor provided
> disks to repair/recreate the VP.

There's a grand assumption there: the vendor disks aren't using Parted.
I think Parted would be a good solution for them.  (Well, perhaps
they need to run on Windows, but Parted could be ported quite cheaply
to Windows, IMHO)

> The utility disks will create a new partition table, a new VP,
> a filesystem (or some other datastructue) on the VP and populate the 
> filesystem.  
> 
> In most cases (I think) the Vendor has never specified what format the VP 
> has. They may change
> it. This doesn't matter. I would treat the VP as a blob. The internal format 
> is irrelevant. I
> would never waste my time reverse engineering the format. 

We might be able to get docs / help.

> At the moment the on time that I worry about the VP is when 
> 
> 1) I want to partition my harddrive (I don't want to destroy the VP) 
> 2) I want to back up my computer (I have to back up the VP).
> 
> To solve 1) you might have parted check to see if the drive has a VP. If it 
> has do not wipe the
> partition table and do not remove the VP.

Do you mean with "mklabel"?  Couldn't the user just "rm" ?

> 2) is more important IMHO. Whenever I install Linux on a computer with a VP i 
> get very nervous.
> If I fsck up I have a lot of work ahead of me. I took me half a day to create 
> a new VP on my
> old Compaq Laptop when I messed up. (The actual procedure took 15 minutes. 
> Finding the damn
> restoration disks on the website took forever :( )

Ah.

> Use parted to copy the partition. To restore the computer do the following. 
> Create a partition
> table with parted or fdisk. Use parted to copy back the partition. Use fdisk 
> to set the 
> partition code. Not very elegant either.
> 
> What I would like is something like
> 
> parted save-vendor-state /dev/hda ~/backup
> parted restore-vendor-state ~/backup /dev/hda

I think this is mostly a special case of partition imaging.
What's a good UI for that?  (From within parted?)

> This way you can treat all VPs the same. 
> 
> When it comes to the other partition codes I don't know what to do. I guess 
> you could talk to 
> the Hurd people and convince them to use a Linux partition :) 

I should put all my rants on a website, shouldn't I?!

> I think the reason you are having a hard time to come up with a clean way to 
> treat partition
> codes is that there isn't any one way. Diffrent partitions belong to diffrent 
> classes. VPs
> being one of them. Normal filesystems is another This class can be divided 
> into the the class
> of fs which parted can create and the class of fs that parted cant create. ( 
> I don't think it 
> is desirable for parted to be able to create every fs known to man. ) Things 
> like the Partition
> Magic partition type fall into a third class. There might be more. 

I agree.  I'm trying to put everything into a box, to make some sense
out of the mess.  But at the end of the day, it's still a mess, hehe.

But, I think an approach of:
 (1) put as much in the box as possible
 (2) have an ugly fdisk-like UI for everything else
Is a reasonable compromise

> To get clean code you will (probably) have to deal with the classes 
> diffrently. 
> 
> Ok thats enough random ramblings for one night :)

;)

Cheers,
Andrew