Converting AFM relationship to AFM DR
A working AFM single writer (SW) or independent writer (IW) relationship can be converted to a primary/secondary relationship.
Complete the following steps:
Note: In case of multiple IW caches to the same home, you can
convert only one to primary.
After the primary and secondary are converted and connected through primary ID, the
psnap0 queued from the primary fileset is played on the secondary
fileset. The two filesets are ready for use. For more information, see mmafmctl command.
Note:
- IW/SW fileset must communicate at-least once to home before conversion. Newly created and inactive filesets might not convert successfully. When you convert a fileset in inactive state, it will convert to primary but will not create psnap0. Next access of the primary fileset will trigger recovery and create the psnap0 and move the psnap0 and the pending changes to home.
- If applications are in progress on the cache fileset during conversion, some inodes might be orphans and the –check-metadata option might show failures. It might be useful to use the –nocheck-metadata option in such cases.
- If cached files had been evicted from SW/IW cache, conversion with the –check-metadata option might show failures. It might be useful to use the –nocheck-metadata option in such cases.
- If home of an IW fileset is running applications during conversion, IW should revalidate with home to pull in all the latest data before conversion. During conversion, if any file/directory is not present in cache, it might result in a conflict error and fileset might go into NeedsResync state, AFM automatically fixes the conflicts during next recovery.
- You cannot convert a SW fileset that is in an unmounted state or NeedsResync state.
- Resync does not split data transfers even if parallel data transfer is configured, and the target is a mapping.