Re: romfs

Janos Farkas (chexum@shadow.banki.hu)
Mon, 17 Feb 1997 10:36:27 +0100 (MET)


> Hmm, how is the development of romfs? Is this a good fs to use as a live
> filesystem on a CDROM? Can file compression be built into romfs, such

It's designed to run in memory, or another low-latency media, and thus
might not have perfect "performance" on floppy, and there's a slight
chance that it doesn't work from a cd (i.e. it's not tested). Although
when it works, it does use almost no additional memory for its purposes,
and that's its main feature.

> that files under a certain size can be optionally compressed to save

Compression would need quite a bit of code, and only ext2 has somesuch
feature (and that's not even in the main kernel tree). It *could* be
useful to reduce to run-time memory requirements of a ramdisk, but seems
quite a big block to me...

> space? Are all the Unixy attributes useful for such a filesystem present
> (eg device bits (block, character, pipe), sticky bits, read, write,
> ownership, etc?). Just looking for a bit of clarification.

Not every bits are preserved, only those necessary to have a working
boot disks. I.e. directories are rwxr-xr-x by default, files rw-r--r--,
(x bit possible), device & other special files are rwx------ as a quick
feature to make it secure enough to be mounted on a live system... Every
file is owned by root (user/group 0). These are enough to fullfill the
above mentioned purpose, and possibly for other purposes too...

If you have better ideas or need small things handled differently, just
contact me.. :)

Janos