If you are at 5.3.4r2 and you want to back down to 5.3.4 do you first have to run revert_to 5.2 and then upgrade to 5.3.4?
When you run revert_to is says you can only revert to 5.0, 5.1, or 5.2
IANANetappEmployee, but as I understand it, those versions listed for revert_to are where there were structural changes to wafl, and likewise to downgrade, these changes have to be backed out of.
For >5.2 (for now) you can upgrade and downgrade at will just by going through the installation procedure (./install_netapp, download, reboot).
This does bring up an interesting point though: In the cases where we have to downgrade, as unfortunately happens sometimes, are diskfw's regression tested against old versions? Given that netapp knows their disks so well (the block relocation thread comes to mind), certainly there are bug compatibility 'features' that have been hacked in that may cause other problems if a fw is encountered that didn't exist at the time of the release. ...not that I'm real concerned, but this piqued my interest.
..kg..