I’ve written about moving Metadata LUNs from one LUN to another with Xsan in the past, available at https://krypted.com//unix/replacing-xsan-metadata-luns. There, we were using sndiskmove, which works when moving Metadata LUNs from Xsan to Quantum appliances as well (e.g. a 440 or 662). However, the drives that Quantum provides in these appliances are much smaller (and much faster) than those in a traditional Xsan environment. Therefore, the sndiskmove approach would fail as you’re moving from a larger to a smaller LUN.
Because the amount of space that you’re using on a Metadata LUN, you should be able to gracefully move metadata to a much smaller LUN. To do so, Quantum provides the snmetadump command. Before using snmetadump stop the volume. To use snmetadump, run it with a -dc option, followed by the name of the volume (or file system if you will), as follows (assuming a volume name of golden girls) from the StorNext metadata controller:
snmetadump -dc goldengirls
Once run, the metadata LUN will be backed up to /usr/adic/database/metadumps. You would then run the -a option to apply your changes:
snmetadump -a goldengirls
You can then edit the config files (which at this point would be cfgx) and then reformat the metadata for the new destination using -amMs again followed by the volume name:
snmetadump -amMs goldengirls
Finally, restore metadata (which according to the config files it will go to the correct LUN:
snmetadump -r goldengirls
Now you should be able to start your volume back up and be back to functional, with your Metadata LUNs on your shiny new appliance. .
