[rrd-users] rrds on ext2 partition?

[Scott Brumbaugh]

Hi Bernard,

On Mon, Jul 07, 2008 at 04:27:31PM -0700, Bernard Li wrote:
> In conjunction with the ongoing discussions here and in rrd-developers
> on "accelerating" rrdtool (either via using RAM/SSD as the underlying
> storage component) or having an accelerator daemon, I'd like to hear
> your thoughts on using ext2 as the underlying filesystem for storing
> the rrds (or any other filesystems).
> 
> My current experience is with lots of rrd files on ext3 filesystem
> which causes high load and high I/O resulting in unusable system.
> When I put the rrds in an ext2 filesystem, load has dropped
> dramatically and it still has fairly high I/O, but at least the system
> is not locked up.
> 
> The downside is without the journal, you have the possibility of
> having data corruption upon power loss, but much could be say about
> storing data in tmpfs even with periodic syncing of data to persistent
> store.
> 
> Thoughts on this?
> 
> P.S. In case you are wondering, rrdtool is used in conjunction with Ganglia.
> 
> Cheers,
> 
> Bernard
> 

I would suspect that the journal updates with ext3 would impact
performance of rrd_update.  Not having experimented much with it,
there are different ways to mount an ext3 filesystem that treat the
journal differently.  I have read discussions where it was claimed
mounting with data=writeback will give better performance with a
heightened risk of corruption.  There are a lot of links on google
about it.  Here is one:

   http://www.ibm.com/developerworks/library/l-fs8.html


Scott B