[Lustre-discuss] 1.8.1.1 too :) # Re: 1.8.1 test setup achieved, what about maximum mdt size

[Piotr Wadas]

[..]

> As you can see, my MDT, at just less than 20% of the size of my total
> OST storage is quite oversized (by 10x perhaps?) for the data I am
> storing, and I store lots of small files -- Lustre, kernel and other
> misc source trees.  I don't do any striping however, which helps keep
> MDT usage lower.
> 
> > If you are using LVM you can increase the size of the MDT device and
> > resize the filesystem to add more inodes to the filesystem.
> 
> Ahhh.  I don't think I knew that resizing actually increased inode
> counts.
> 
> Just for the experience of it, (and when I can find a moment to do it) I
> will probably transplant my MDT into a newly created (on LVM of course,
> given I do everything on LVM) device, much smaller than my current one.
> Indeed, I could try just shrinking the existing one, but I want to
> create a new one from scratch, complete with a mountconf- style UUID and
> move the MDT data into it.

Well, I'm happy to report test setup "upgraded" to 1.8.1.1 ;-) Now, 
regarding this topic - I experiment with lustre quota features. How MDT 
usage reflects to storing of quota information? Seems, it's still based on 
quota v1/v2 files somehow, although as described in chapter 9.1 Lustre 
Manual, usrquota and grpquota mount options are obsolete on fs client. I 
do not expect surprises here, I mean size of storage of quota info will be 
probably not worth to mention, anyway this is interesting how it's 
actually stored ? Is it some classic quota combined with live per-ost 
summary?

Regards,
DT