[lustre-discuss] Speed of deleting small files on OST vs DoM

[Åke Sandgren]

Hi!

Is there a good reason why deleting lots of small files (io500 test
md_easy/hard_delete) with the files on OSTs are up to two times faster
then when using DoM with the whole file(s) on the MDT?

Using server/client 2.13.0
DoM up to 64k, test files < 4k

I can see that the actual data deletion with the data on OST is
asynchronous, but I see no reason for it to be almost two times faster.

Both MDT's and OSTs are SSDs.

The situation is basically the same for a single task and for multiple
clients with multiple tasks/client.

-- 
Ake Sandgren, HPC2N, Umea University, S-90187 Umea, Sweden
Internet: ake at hpc2n.umu.se   Phone: +46 90 7866134 Fax: +46 90-580 14
Mobile: +46 70 7716134 WWW: http://www.hpc2n.umu.se