Jeff Garzik wrote:
> Phillip Lougher wrote:
>
>> 2. Squashfs compresses inode and directory information in addition
>> to file data. Inodes/directories generally compress down to 50%, or
>> say on average 8 bytes or less per inode.
>
>
> squashfs or mksquashfs?
mksquashfs...
>
> A r/w compressed filesystem would be darned useful too :)
>
> Jeff
>
A r/w compressed filesystem may be my next project... As a couple of
people have mentioned there are compressed r/w filesystems already
out there.
As you'll know, there are always tradeoffs with filesystem design,
it is very difficult to get as good compression with a r/w fs
than with a read only filesystem. I wanted to get maximum
compression, and quite a few of the techniques I use rely on
its read-only nature.
An append only (i.e. files can be added, but not modified), fs might
be a useful compromise. With compressed metadata, any modification
of files will inevitably achive different compression ratios, and so
modification of metadata/files in place is not an option. Appending
modified metadata/data brings you to log-structured (journalling)
filesystems and compaction (log cleaning) requirements with consequent
loss of compression.
Phillip
>
>
>
>
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This archive was generated by hypermail 2b29 : Thu Oct 31 2002 - 22:00:50 EST