Closed piergiaj closed 9 years ago
Hi there. What OS and filesystem are you using?
OS: Linux 3.0.101-0.31.1_1.0502.8394-cray_gem_c
File system is dvs
Hi again,
I'm going to guess there's a 90% chance dvs doesn't support mmap, but in order to confirm this, can you upload a gist containing the output of strace -s 100 python your/script.py
. If it is mmap, then we can't support LMDB on that filesystem, however if it's another system call returning the error, it might be possible to work around it
The Cray documentation confirms, they only support read-only mmap on DVS. http://docs.cray.com/books/S-0005-5204/ page 39 caveats.
Hi there,
hbf suggests you might be fine running with writemap=False
, since DVS supports read-only mmaps, however be aware that this still does not allow opening the database from multiple nodes in your cluster, as DVS does not provide any coherency between the in-memory database file and its current representation on disk, and even if it did, LMDB does not support any kind of locking that would work in this scenario.
sbatch --gres=gpu:1 tr.sh
Where tr.sh is my test script
I have met the same problem, which caused by system lock, like notebook cpfs_data folder has system lock, but nas_data folder has not.
Whenever I call open, whatever string I pass in as the path, it gives the following error:
The error line always matches the string I pass in. The folder is created and a lock file is created, but I always get this error. Any ideas how to fix this?