Re: xfs spanning over ssd and hdd

[Matthias Neuer <mneuer@xxxxxx>]

Hi.

On 05/12/2014 04:20 PM, Eric Sandeen wrote:
> On 5/12/14, 7:58 AM, Matthias Neuer wrote:
> > Hi.
> >
> > I have a slow and big hdd and a fast but small ssd and want to test the 
> > following setup but don't know if it's possible.
> >
> > Use LVM to concatenate the ssd and the hdd linearly. Create a xfs filesystem on 
> > this device such that the sdd is filled first, i.e. data is written to the ssd 
> > as long as there is free space, otherwise the data is written to the hdd.
> >
> > I have applications which may benefit from this setup but I am not sure so I 
> > need to do some benchmarks.
> XFS doesn't fill from the front, so you can't configure things to fill the HDD 
> first.
>
> Files in new directories rotor around the allocation groups on the filesystem, 
> so all regions of the fs are filled more or less evenly.
Ok, thanks for the info. I fear that xfs is too intelligent because 
filling the device from front to rear seems to be a simple policy.
Maybe I should try FAT16 :)

Thanks
Matthias