Re: Reiser4 Fragmentation

[geearf@free.fr]

----- Mail Original -----
"Edward Shishkin" <edward.shishkin@gmail.com> wrote:
>geearf@free.fr wrote:
>Hello.

>measurefs.reiser4 is pretty ancient, and I guess
>that it works incorrectly for compressed files.


>(External) fragmentation resulted in a number of "extents" is
>a sticky thing inherent to all linux file systems, including reiser4.
>Currently there is no tools to reorganize reiser4 without having
>a spare partition. However, it is possible to create something
>simple like xfs_fsr: it would be an appreciable help.

>The "smart reiser4 repacker" based on the flush algorithm was
>supposed to be the paid option, and therefore there are some
>obvious issues of its development.

>Internal fragmentation, resulted in wasteful space utilization
>("holes" in the metadata blocks") would mean a bug in the code.
>This fragmentation can be measured as 1 minus  the fraction
>du (1) / df (1). Note, that du (1) should be applied to the semantic
>root. If you have ccreg40 partition, then check it with
>"fsck.reiser4 --fix" prior using du (1). Also make sure (for example
>with sync (1)) that there is no dirty pages prior using df (1).
>If the internal fragmentation is more then 0.02, while du (1) is
>large enough (> 100 000), then, please, report.

>Thanks,
>Edward.

Well I ended up taring my /, mkfs and untaring it.
So it should not be fragmented in any way anymore.
I will look at the internal fragmentation of my /home, but this is not under ccreg40.

I've also just looked at the xfs_fsr thing and it looks pretty useful.
Can't that be done with a simple script? (sort of like Con's defrag script) or does it need to be related to R4 ?

Thanks Edward,
John