[Lustre-discuss] strange slowdown

[Aaron Knister]

Please bear with me while I try to explain this problem. It's very  
strange.

I have a 33TB lustre file system with 5.6 underlying LUNs. The  
interconnect is infiniband. Any write I/O to the disk causes the mount  
to hang, and the underlying disk starts doing lots and lots of tiny  
reads for about 10 minutes. There is only one client mounted and this  
small I/O continues after killling the client. I am running lustre  
1.6.3 with the latest rhel5 kernel on rhel5. I cannot find any  
suggestive error messages and am at a loss. It's a production  
filesystem and it's pretty much unusable.

-Aaron