Re: LVM root?

[Goswin von Brederlow <brederlo@informatik.uni-tuebingen.de>]

Lennart Sorensen <lsorense@csclub.uwaterloo.ca> writes:

> On Mon, Oct 09, 2006 at 03:01:24AM +0200, Goswin von Brederlow wrote:
>> You need an initrd or initramfs even if you compile a custom kernel.
>
> Why would you bother building your own kernel for most machines?  Why
> would you not use an initramfs?

Because it is way to fragile (fails half the time) and you can't use
init=/bin/sh anymore.

>> I like to boot into my / with init=/bin/sh, have an editor, netcat,
>> the lvm tools and all that available to look around and fix things in
>> case something does go wrong. With a standard initrd that is pretty
>> much an impossibility and you need that for / on lvm.
>
> If the initramfs is done right (initramfs-tools seems to do the job
> well), then you should still be able to boot and get at your root
> filesystem and do that.

Maybe I've been using the wrong tools back then (initramfs is somewhat
new) but that never worked right for me.

>> You can put swap on lvm. You should also think about suspend to disk,
>> which needs enough swap to store all active memory. Twice your ram
>> isn't a bad idea. Same as ram is pretty much a must.
>
> Why would anyone without a laptop care?

Seems that some desktop users like to not shut down all their apps
when they turn of the system for the night.

>> You might want to stripe the volume for editing accross both
>> disks. Lvm can do that without you having to resrot to raid0. Gives
>> you more speed on file I/O. It's a per volume thing so you can keep
>> /usr, /var, /home on the first disk and just stripe the editing LV
>> when you get the 2nd disk.
>
> LVM can do that, but as soon as you start to add to the LVM later you
> loose it.  In general it isn't recommended to use the stripping features
> in LVM.

You do? That would be a bug or at least missing feture then. Recently
there has been some work on raid support inside lvm (raid1 support was
added) so I don't think it is totaly deprecated.

> --
> Len Sorensen

MfG
        Goswin