Re: The future of disk encryption with LUKS2

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

 



Thanks, clearer now.

On Sat, Feb 06, 2016 at 04:18:29 CET, Sven Eschenberg wrote:
> Might be, or I was just unable to communicate my thoughst properly.
> 
> The first paragraph rather commented on Robert's post. He talked
> about LVM and I wanted to point out that LVM is not a good example
> of how to properly handle resizing, as it fails to properly resize
> for multiple metadata locations. (A secondary header implies that
> all changes on both headers need to be atomic and in sync. While
> this is doable, LVM clearly shows, that it is not trivial, otherwise
> it would certainly be available as feature by now).
> 
> The second paragraph commented on your statement regarding
> filesystem resizing the way LVM handles it (lvm --resize). You
> stated this would limit the possible filesystems in the dm-crypt
> container where a resize could be done. I agreed that it is limited
> to those supporting online resizing. LVM uses fsadm which in turn
> uses the filesystem's API to do the resize operation. The operation
> is then commenced by the fs driver. You already said before, that
> you rather recommend to recreate the filesystem. If one goes this
> path, then there is no need for a resize operation on dm-crypt's
> side either. If you recreate the fs, then you can aswell just
> recreate the dm-crypt container instead of resizing it.

I think I did recommend that. At least that was the idea:

1. Do backup
2. Resize partition 
3. Recreate LUKS container and restore backup

Far less ways for this to go wrong. And unless 1. is broken,
you can try again.

> IMHO a dm-crypt resize operation only makes sense, if you plan to
> resize the filesystem aswell. Otherwise just backup and recreate.

I agree to that. So maybe to satisfy KISS, it would be preferrable
to not even have container resize, even when the container becomes
aware of its size, unlike now. 

Regards,
Arno
-- 
Arno Wagner,     Dr. sc. techn., Dipl. Inform.,    Email: arno@xxxxxxxxxxx
GnuPG: ID: CB5D9718  FP: 12D6 C03B 1B30 33BB 13CF  B774 E35C 5FA1 CB5D 9718
----
A good decision is based on knowledge and not on numbers. -- Plato

If it's in the news, don't worry about it.  The very definition of 
"news" is "something that hardly ever happens." -- Bruce Schneier
_______________________________________________
dm-crypt mailing list
dm-crypt@xxxxxxxx
http://www.saout.de/mailman/listinfo/dm-crypt



[Index of Archives]     [Device Mapper Devel]     [Fedora Desktop]     [ATA RAID]     [Fedora Marketing]     [Fedora Packaging]     [Fedora SELinux]     [Yosemite News]     [KDE Users]     [Fedora Tools]     [Fedora Docs]

  Powered by Linux