[Server-devel] RW Compressed FUSE FSs? (Re: XS - XO archiving and backup)

[Martin Langhoff]

On Mon, Nov 10, 2008 at 10:49 AM, Greg Smith <gregsmitholpc at gmail.com> wrote:
> On backup and restore, aside from the comments already mentioned, I
> suggest you pay careful attention to the available space on your XS. You
> should have about 2GB free space on your XS for each XO. If you don't
> have enough space it may move some of the files over your wireless LAN
> then not save them on the XS.

Excellent point. Which leads to a request - good references on a well
behaved compressed FUSE FS that

 - supports RW
 - behaves well with rsync (which I presume mmaps files liberally)
 - supports hardlinks and ACLs

As a happy user of large hard drives, I haven't needed a compressed FS
since the unhappy days of DRDOS so I'm rusty on this front. There's a
listing at http://fuse.sourceforge.net/wiki/index.php/CompressedFileSystems
but I know nothing about the quality, reliability and performance.

I care mainly about the reliability -- but it better be fast too.
Compression ratio is perhaps more negotiable, the other two arent :-)

A good FS  would give us huge benefits on the backup front:

 - Right now, the jffs2 fs can outstore the backup storage on highly
compressible content. Not a good look, and leading to all sorts of bad
scenarios.

 - More storage means the backup quota for each user can hold more "old" files.

 - Reasonably good compression means that we can squeeze HD space a
bit, for example in really large schools.

> For more background, see this thread:
> http://lists.laptop.org/pipermail/server-devel/2008-September/002058.html
>
> Also, this feature is on by default when using XO 8.2 and XS 0.4.
> There's no GUI to turn it off but I assume you could disable it on the
> XS with a few manual changes to the config.

There's a config file (/etc/httpd/conf.d/ds-backup.conf I think) -
remove it and ds-backup is no more.

cheers,




martin
-- 
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 martin at laptop.org -- School Server Architect
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