[nylug-talk] Filesystems that Support Transparent Compression?

[alex@pilosoft.com]

On Tue, 11 Jul 2006, Ron Guerin wrote:

> Yusuke Shinyama wrote:
> 
> > Today I was asked if we can use any filesystem on Linux that
> > supports transparent compression. Because we're trying to handle
> > hunderds of gigabytes of XML data that can be compressed very well
> > (about 80-90% size reduction), we could save a lot of disk space
> > by using such a filesystem.
> 
> I've never understood why a feature which became standard with PC
> operating systems in the 1980's has yet to become standard with Linux. I
> tend to do more long-term storage on my Windows boxes than my Linux
> boxes precisely because the Windows boxes allow me to more cheaply store
> the data.
Because this isn't compatible with unix sematics for filesystem, and 
doesn't make sense.

Example: You have 20GB file, compressed into 10G. Now, you mmap'd it, and 
need to fetch byte #44444444. To do that, you need to uncompress entire 
file. Now, you modify a byte there. To write that, you need to recompress 
entire file. Etc.

-alex