[Lustre-discuss] More Efficient Method of Messuring Usage?

[Mike Hanby]

Howdy,

I just ran a disk usage report for our Lustre (v1.8.1.1) scratch space (6TB used of 40TB) that ended up taking 25 hours to complete. Yikes.

I'm wondering if anyone can suggest a more efficient way to get disk usage data?

The disk usage script in question works as follows
1. builds an array of directories to check (/scratch/user1 /scratch/user2 / scratch/user3 and so on)
2. loops through the array running the Linux 'du' command on each user directory storing the results in a new array
3. Once the loop completes a report is generated and emailed using the results array

Steps 1 and 3 run very quick, so step 2 is the long straw. Traditionally, this script has been used on our local home directories and will complete in approximately 15 minutes (for ~ 1TB of usage).

I should mention that my 25 hour test was run from a Lustre client. We have one MDS and two OSS (each serving 3 OSTs). Also, we do not have any quota enabled.

Thanks for any suggestions,

Mike

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Mike Hanby
mhanby at uab.edu
Information Systems Specialist II
IT HPCS / Research Computing