Hi Julian, > I want to adapt the I/O statemachines to reread the dfile array in case a I/O > server responds with PVFS_ENOENT during the flow or within the inital I/O > ACK. This might happen if the file is migrated away and the client does not > have the updated dfile array befor it initiates the I/O. > Thus, I want to reread the dfile array and only restart the I/O for this > particular server. The progress of the other I/O requests should not be > influenced. > While looking at the sys-io.sm I wonder if the transition for the case > IO_RETRY in the state io_analyze_results does this. Maybe some extra lines > could be added for example to restart the process if the initial acknowledge > returns with PVFS_ENOENT and also do not increase the retry count in this > case ? > I'm thankful for any suggestions how that could be implemented easily.
Let me try to understand the scenario a little better. You wish to migrate the files from a server to another server in which case we would need the location of the new server/file system paths etc to be passed back in the server responses, no? The other alternative as you suggest is let the server return ENOENT, and have the client talk to the MDS and do a getattr again to get the dfile handles and their locations (the assumption here being that the migration tool (server migration tool that is) does the right thing in updating the dspace of the meta file) Given that a few client-side caches (ncache, acache) etc are now in the tree, we also need to think about adding some new error codes for stale handles, stale servers etc if we go about adding server migration? > > In this context a weird error message: > In case the fs is corrupted, e.g. there is a metafile pointing to a non- > existing datafile I think the I/O should abort quickly instead of doing > retries (in the migration case retry to get dfiles if they did not change > abort). Currently on the client sm returns the error: "Operation now in > progress". You can try this by removing a datafile with pvfs2-remove-object > (first get object number with pvfs2-viewdist). Agreed. This should be easy to do.. Thanks, Murali > > thanks, > julian > > --- > Ben (Obi-Wan) Kenobi: > Use the Force, Luke! > _______________________________________________ > Pvfs2-developers mailing list > [email protected] > http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers > > _______________________________________________ Pvfs2-developers mailing list [email protected] http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers
