[Lustre-discuss] OST load distribution
Jure Pečar
pegasus at nerv.eu.org
Wed May 8 06:12:52 PDT 2013
Hello,
I have a lustre 2.2 environment which looks like this:
# lfs df -h
UUID bytes Used Available Use% Mounted on
lustre22-MDT0000_UUID 95.0G 9.4G 79.3G 11% /lustre[MDT:0]
lustre22-OST0000_UUID 5.5T 2.1T 3.3T 39% /lustre[OST:0]
lustre22-OST0001_UUID 5.5T 1.2T 4.3T 22% /lustre[OST:1]
lustre22-OST0002_UUID 5.5T 1016.0G 4.5T 18% /lustre[OST:2]
lustre22-OST0003_UUID 5.5T 948.3G 4.5T 17% /lustre[OST:3]
lustre22-OST0004_UUID 5.5T 812.3G 4.7T 15% /lustre[OST:4]
lustre22-OST0005_UUID 5.5T 641.4G 4.8T 11% /lustre[OST:5]
lustre22-OST0006_UUID 5.5T 619.4G 4.8T 11% /lustre[OST:6]
lustre22-OST0007_UUID 5.5T 587.0G 4.9T 11% /lustre[OST:7]
lustre22-OST0008_UUID 5.5T 539.7G 4.9T 10% /lustre[OST:8]
OST0009 : inactive device
lustre22-OST000a_UUID 5.5T 531.3G 4.9T 10% /lustre[OST:10]
lustre22-OST000b_UUID 5.5T 488.9G 5.0T 9% /lustre[OST:11]
lustre22-OST000c_UUID 5.5T 451.2G 5.0T 8% /lustre[OST:12]
lustre22-OST000d_UUID 5.5T 450.1G 5.0T 8% /lustre[OST:13]
lustre22-OST000e_UUID 5.5T 448.8G 5.0T 8% /lustre[OST:14]
lustre22-OST000f_UUID 5.5T 444.0G 5.0T 8% /lustre[OST:15]
lustre22-OST0010_UUID 5.5T 422.5G 5.0T 8% /lustre[OST:16]
lustre22-OST0011_UUID 5.5T 414.5G 5.0T 7% /lustre[OST:17]
lustre22-OST0012_UUID 5.5T 406.9G 5.1T 7% /lustre[OST:18]
OST0013 : inactive device
Reading through documentation I see that lustre should prefer those OSTs with most free disk space (qos_prio_free is set to 91%). However my monitoring tells me that OST0000 is the most loaded by far, having loadavg over 300 and network traffic 3-5x higher than the rest.
I raised qos_threshold_rr to 55% and am waiting to see the results. Right now I have clients reading and writing to this fs at around 600MB/s aggregated, generating hundreds of files per job.
How soon am I expected to see the results?
What else can I do to spread the load from OST0000 evenly among the other OSTs?
--
Jure Pečar
http://jure.pecar.org
More information about the lustre-discuss
mailing list