Which compression is recommended?

[hungarianhc]

Hi there,

I know that people are going to say that my question is a bit too open ended, but to make it more specific... I'd like to enable compression on a volume for my new FreeNAS box I'm building tomorrow. I don't want much of a performance penalty. I will have a lot of media files, which I know don't benefit too much from compression, but I'll also be hosting my uncompressed time machine backups, file syncing, etc. Also, I'll be using the Intel Avoton Atom C2750 (8-core) CPU. Are there some specific hardware features I should be looking for that would help w/ compression performance, like AES-NI for encryption? Thanks!

 

[Yatti420]

There is compression on by default now I believe.. It shouldn't have a big CPU impact unless you chose 2 use slower / more powerful compression. If i'm going to do encryption I would get a CPU with the appropriate instruction set ( AES-NI? can't remember what it's called) to keep speeds up..

 

[hungarianhc]

Okay I think you might be right... I'm looking at the documentation here: http://doc.freenas.org/index.php/Volumes#Compression

Code:

If you leave the default of Inherit, the dataset will inherit from the parent. Unless the parent dataset has been modified, its default compression level is lz4.

It sounds like they're saying that if I don't change anything, LZ4 compression is going to be on by default.

 

[dlavigne]

Yup, and lz4 is the current recommended. Good compression with neglible performance impact.

 

[hungarianhc]

Love it! I'm getting more and more pumped about my FreeNAS build that I get to put together tomorrow :)

 

[indy]

Compression benefits are pretty solid on uncompressed files but basically zero on media files.
However lz4 has very little cpu demands and aborts on incompressible files anyway.
Just leave it on and don't worry about it - don't expect too much though.

 

[HoneyBadger]

The C2750 supports AES-NI, and we've got a user here who is using it with lz4+encryption and is basically able to saturate GbE (90MB/s transfers over FTP or CIFS)

http://forums.freenas.org/index.php?threads/atom-c2558-a1srm-2558f-freenas-compatibility.17462/