[Lustre-discuss] Speeding up configuration log regeneration?

[Olli Lounela]

Hi,

We run four-node Lustre 2.3, and I needed to both change hardware  
under MGS/MDS and reassign an OSS ip. Just the same, I added a brand  
new 10GE network to the system, which was the reason for MDS hardware  
change.

I ran tunefs.lustre --writeconf as per chapter 14.4 in Lustre Manual,  
and everything mounts fine. Log regeneration apparently works, since  
it seems to do something, but exceedingly slowly. Disks show all but  
no activity, CPU utilization is zero across the board, and memory  
should be no issue. I believe it works, but currently it seems the  
1,5*10^9 files (some 55 TiB of data) won't be indexed in a week. My  
boss isn't happy when I can't even predict how long this will take, or  
even say for sure that it really works.

Two questions: is there a way to know how fast it is progressing  
and/or where it is at, or even that it really works, and is there a  
way to speed up whatever is slowing it down? Seems all diagnostic  
/proc entries have been removed from 2.3.  I have tried mounting the  
Lustre partitions with -o nobarrier (yes, I know it's dangerous, but  
I'd really need to speed things up) but I don't know if that does  
anything at all.

We run Centos 6.x in Lustre servers, where Lustre has been installed  
from rpm's from Whamcloud/Intel build bot, and Ubuntu 10.04 in clients  
with hand compiled kernel and Lustre. One MGC/MGS with twelve 15k-RPM  
SAS disks in RAID-10 as MDT that is all but empty, and six variously  
build RAID-6's in SAS-attached shelves in three OSS's.

ATdhvaannkcse for any help,

-- 
     Olli Lounela
     IT specialist and administrator
     DNA sequencing and genomics
     Institute of Biotechnology
     University of Helsinki