Re: [HPDD-discuss] Stale File is it possible?

Hi Amit and Patrick, On 09/04/2015 11:09 PM, Patrick Farrell wrote: sure. At first I didn't relate this question to short reads, but "Erroneous read. Read 1 instead of 8" sounds a bit like short reads. On the other hand, are these numbers in bytes? If that's the case I would doubt it's a short read of a single byte. I would expect that at least the block size is read in one IOP (unless the application really reads each byte separately). At biowulf.nih.gov/apps/gaussian/#errors I have found the "translation to English": Disk quota of disk size exceeded. Could also be disk failure or NFS timeout. If you are really close to the quota limit, it might happen that the client thinks that it could write the data, and until the next read happens, the quota mechanism has wiped away a few bytes. At least I have seen such a behavior on NFS. Full OSTs could perhaps cause similar behavior Another issue comes to my mind: Which kind of locking is used? It can be specified in the mount options. Locking might slow down lustre a bit (also depending on the version you are using). No mount option at all means there is no locking and thread A does not notice that thread B has the file still open. But the error message you wrote suggests that at some locking is active. localflock handles locking on each client locally, so the threads notice that the file is still in use as long as the owner is on the same node, and flock does global locking. Maybe you have to switch to global flock if you use several nodes within one job. maybe you can see something with strace? But I'm not sure if you are allowed to do such kind of debugging Martin