On 09/06/2020 14:57, Jonathan Buzzard wrote: [SNIP]
I actually thinking on it more thought a generic C random UID/GID to UID/GID mapping program is a really simple piece of code and should be nearly as fast as chown -R. It will be very slightly slower as you have to look the mapping up for each file. Read the mappings in from a CSV file into memory and just use nftw/lchown calls to walk the file system and change the UID/GID as necessary.
Because I was curious I thought I would have a go this evening coding something up in C.
It's standing at 213 lines of code put there is some extra fluff and some error checking and a large copyright comment. Updating ACL's would increase the size too. It would however be relatively simple I think. The public GPFS API documentation on ACL's is incomplete so some guess work and testing would be required.
It's stupidly fast on my laptop changing the ownership of the latest version of gcc untarred. However there is only one user in the map file and it's an SSD. Obviously if you have billions of files it is going to take longer :-)
JAB. -- Jonathan A. Buzzard Tel: +44141-5483420 HPC System Administrator, ARCHIE-WeSt. University of Strathclyde, John Anderson Building, Glasgow. G4 0NG _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss
