Disk compression... for speed...

[extide]

Anyone here have any experience with doing this sort of thing?

[Menelmarar]

No.

It seems fallacious as first thought, mainly because I would associate compression with adding latency and reducing performance due to having to decompress on access and compress on storage. However; on second thought, it's interesting. As long as your application isn't CPU intensive, and the compression algorithm doesn't CPU bottleneck you, you should be able to get more data if it's compressed.

Kind of like sending data over the internet, you can send more data in a shorter time when compressed.

Sounds like a headache I wouldn't want to deal with balancing though.

[SJetski71]

http://www.hardforum.com/showthread.php?t=959556

[extide]

Yeah, see that post is from 2005 and CPU's are far faster now even. I have some folders on my drive compressed but not stuff that's used much. I wonder what a good way to benchmark would be if I say compressed the program files dirs and the windows dir...

[unhappy_mage]

The best answer to this question is "try it". I've seen some postings on the ZFS mailing lists indicating that people actually do see performance improvements with compressable files from turning on lzjb compression, but gzip generally slows things down (although it does compress better). I have no idea what algorithm Windows uses to compress files, or where it stands on the time/space tradeoff.

[tdg]

I think try it is the only way to know. I haven't used compression since the Win9x days when I was low on space, and back then it definitely caused a performance hit. With modern CPU's and whatnot I'd expect it to be much more transparent, but your still going to be trading off reduced hard disk transfer for an increase in latency caused by the deflation/compression. Maybe a good HDtach test to give some basic results both ways.

The best answer to this question is "try it". I've seen some postings on the ZFS mailing lists indicating that people actually do see performance improvements with compressable files from turning on lzjb compression, but gzip generally slows things down (although it does compress better). I have no idea what algorithm Windows uses to compress files, or where it stands on the time/space tradeoff.

Windows is still using the LZ77 algorithm as far as I recall for compression, just a modified ZIP. Definitely no ZFS form of transparent compression :).

[Nenu]

A downside of compression is should there be a bad sector, you are more likely to lose data.
You might lose a small amount of data on an uncompressed drive such that you can repair a document say, but when compressed, any error larger than the file systems OR decompressors correcting capability will result in a much larger loss of data.
Its a good idea to backup anything important regularly.