Re: [tlug] Raid5 box & backup

[Curt Sampson <cjs@example.com>]

On 2008-05-26 02:37 +0200 (Mon), Christian Horn wrote:

> Case a, plain nfs, unencrypted.
> Pure nfs is used here, usual small files stored on the 2 datastores.
> pros: highest fault tolerence, rsync efficient because it syncs single 
>   files

While you're right about the rsync, I doubt that this would have better
fault tolerence than a journaling filesystem over a network-exported
block device (e.g., iSCSI or that network-exported ATA thing).

And come to think of it, if you had, say, a dozen block devices each
each backed by its own file and used the concatenation of these devices
as a single filesystem, you might well get much better rsync behaviour
(assuming that the timestamps work as they should). Even with a standard
FFS-style FS, you'd only have to sync the files covering the cylinder
groups you'd touched, and if you used something like Berkeley's LFS,
you'd only be updating one file if you'd only made a few changes.

> Case b, plain nfs, files ecrypt encrypted.

Got a reference for ecrypt? You may have the issue, if it's what I think
it is, that it exposes things such as file counts, sizes, and update
times.

cjs
-- 
Curt Sampson       <cjs@example.com>        +81 90 7737 2974   
Mobile sites and software consulting: http://www.starling-software.com