Is it possible to use a local drive to cache an NFS share

Hi All,

I am mounting /home over NFS which is great, but it really kills compile times. So I have a local HDD which I have copied all my source code over from which I do my coding and compiling.

What I would love to do is use the local drive to cache /home. Specifically one user directory under /home - only one machine will ever be modifying the contents of this directory.

Or should I just use rsync?

On a side note - I moved my source code from a 1TB HDD on a 3Gb/s SATA port to an Intel 510 series 250GB SSD on a 6Gb/s SATA port. But I didn't see an appreciable increase in compile speed.

Regards,

Graeme

Hi!

NFS is not really made for caching. Its design idea was mainly that the server should be stateless. There is basically no way to get a notification whether a file was changed remotely without either polling or running an external daemon. There are 2 network file systems which support client caching: codafs and andrewfs. However, they are rather complex to setup and I guess nobody is really using them.

If nobody else changes the files you should be fine. But I still would not recommend doing this, because this is basically a time bomb which might go off after you forget what you are doing now. Also there should not be that much performance difference for your worklead unless either your network or your nas is very slow.

After a quick search I have found this project (not sure what it does exactly):
http://sourceforge.net/apps/mediawiki/fuse/index.php?title=FileSystems#mcachefs

How do you want to sync it back?

This does not suprise me. Compiling mostly stresses the cpu(s).

-Michi

programing a layer 3+4 network protocol for mesh networks
see http://michaelblizek.twilightparadox.com

Hi :)

I suggest to use ccache, if your focus is only about compiling.

Then configure ccache to use your local drive as the directory to store the cache objects.

IMHO, that should be doable :)

regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com

Hi!

ccache caches the compilation result, but it still needs to reads the source code files and write the object files...

-Michi

programing a layer 3+4 network protocol for mesh networks
see http://michaelblizek.twilightparadox.com

Hi,

NFS client support FSCache support which is default in recent kernels CONFIG_NFS_FSCACHE=y, But as I remember, it is a read cache (not even write-through), so a compile load generates lots of new files, so those won't really be benefited by FSCache.

But as you are pointing out, your setup is a single user access, so probably you can relax some of the NFS consistency options, e.g. async mount is really suitable for your case, also you can increase actimeo values. Compiler writes will hit-page cache and with asynchronous writebacks, it is way more faster than SSDs :).

-Rajat