grub-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: GRUB and the risk of block list corruption in extX


From: Vladimir 'phcoder' Serbinenko
Subject: Re: GRUB and the risk of block list corruption in extX
Date: Fri, 8 Feb 2013 17:57:27 +0100

This is not a complete answer but one of my problems is that such requests don't even suply any kind of reason to go into such installs. We nerd to consider usecases before even considering using an approach which is known for some pretty serious problems. Will answer in more details later.

On Feb 7, 2013 11:47 AM, "Martin Wilck" <address@hidden> wrote:
Hello,

this is a question about the long-running topic of installing GRUB in
partitions or partitionless disks.

Recently I have been involved in discussions about this on
https://bugzilla.redhat.com/show_bug.cgi?id=872826. The Fedora boot
loader can't be installed in partition headers any more. The major
reason given by the Fedora developers is the famous GRUB warning
"blocklists are UNRELIABLE and their use is discouraged."

The Grub manual says "installing to a filesystem means that GRUB is
vulnerable to its blocks being moved around by filesystem features such
as tail packing, or even by aggressive fsck implementations".

I'd like to understand how this blocklist corruption might come to pass
(except for cases where "core.img" itself is moved, deleted, or
overwritten by user space tools). Also, it has been recommended to
prevent accidental corruption by setting the IMMUTABLE flag on core.img,
and I'd like to ask for the GRUB experts' opinion about that.
Finally I'd like to know if it's true that the GRUB team plans to drop
block list support altogether in a future version.

Regards
Martin Wilck

PS: It has been stated that of recent filesystems, this matters most for
extX, because btrfs has a 64k header where embedding GRUB is usually
possible. Therefore I asked a similar question on ext4-devel.



--
Dr. Martin Wilck
PRIMERGY System Software Engineer
x86 Server Engineering

FUJITSU
Fujitsu Technology Solutions GmbH
Heinz-Nixdorf-Ring 1
33106 Paderborn, Germany
Phone:                  ++49 5251 525 2796
Fax:                    ++49 5251 525 2820
Email:                  address@hidden
Internet:               http://ts.fujitsu.com
Company Details:        http://ts.fujitsu.com/imprint

_______________________________________________
Grub-devel mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/grub-devel

reply via email to

[Prev in Thread] Current Thread [Next in Thread]