[lustre-discuss] how to optimize write performances
Riccardo Veraldi
riccardo.veraldi at cnaf.infn.it
Thu Sep 30 09:09:53 PDT 2021
Hello,
I wanted to ask some hint on how I may increase single process
sequential write performance on Lustre.
I am using Lustre 2.12.7 on RHEL 7.9
I have a number of OSSes with SAS SSDs in raidz. 3 OST per oss and each
OST is made by 8 SSD in raidz.
On a local test with multiple writes I can write and read from the zpool
at 7GB/s per OSS.
With Lustre/ZFS backend I can reach peak writes of 5.5GB/s per OSS which
is ok.
This anyway happens only with several multiple writes at once on the
filesystem.
A single write cannot perform more than 800MB-1GB/s
Changing the underlying hardware and moving to MVMe slightly improve
single write performance but just slightly.
What is preventing a single write pattern to perform better ? They are
XTC files.
Each single SSD has a 500MB/s write capability by factory specs. So
seems like that with a single write it is not possible to take advantage
of the
zpool parallelism. I tried also striping but that does not really help much.
Any hint is really appreciated.
Best
Riccardo
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