[Lustre-discuss] Is using resize2fs on the MDT a supported option?

[Andreas Dilger]

On 2010-05-14, at 10:41, Adeyemi Adesanya wrote:
> We are are about to install a new Lustre 1.8.2 installation with ~1PB  
> of filesystem space. We have to make a decision regarding the MDT  
> storage and someone suggested that in the event we run out of inodes  
> on the MDT, using resize2fs would be an option (assuming the  
> filesystem was created on an LVM partition).
> 
> Most of the documentation I have read stresses the importance of MDT  
> planning. There is a small mention of resize2fs in the manual but it  
> is not clear if this is a robust, reliable technique or if this would  
> actually give us more inodes. Should we really be setting up a new  
> Lustre installation with the intention of using resize2fs in the future?

I've done this on my personal system w/o trouble, but it isn't something we test internally.  I would recommend making a "dd" backup of the MDT filesystem first, and then test the resize on the backup first, running "e2fsck -f" both before and after to verify it.  Then make another "dd" backup before doing the resize on the real filesystem.  It is always good to have a backup of the MDT in any case.

Cheers, Andreas