XFS over SSD

[Justin Piszcz]

On Mon, 8 Dec 2008, Raz wrote:

> I am thinking of using XFS over a SSD disk.
I am currently using XFS on an Intel X25-E with the logdev internal, using 
the defaults.
I see the point for putting the journal elsewhere; however, that may 
defeat the purpose of an SSD, if its latency is 0.01 or 0.001 and the HDD 
is 8-14ms, then it may defeat the purpose for writes or fast access 
anyhow?

> 1. Can I separate xfs meta data ( not just the logging) from 
the SSD ? > can I put the meta on a different disk ?
Yes, see the logdev option on the mkfs.xfs manpage.

> 2. When does a file's meta ( its block maps ) is being flushed to disk
> ? can I control it ?
I am not sure you can control this, will let the XFS devs/others take on 
this question.