iwcompress and 552?

justin_hardin

I have a freshly converted backing store (5.0.1 -> 5.5.2) and my disk usage went from 71% to 91%. This confused me as the new backing store format was supposed to be leaner?

After poking around, it looks like none of the editions are compressed. I can find nothing in the release notes or docs about iwcompress or autocompress=yes. Should I assume that this feature has been removed?

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Justin Hardin
Sr IS Developer - PeopleSoft

Adam Stoller

5.5.2 does not support edition compression. It was a feature that sounded much better than it really was and was removed during the backing store code re-engineering. (an edition tends to be something like 75% [or higher] references to files that are shared by other editions - and thus all you would be compressing would be references, and not actual data, saving you next to nothing in terms of disk space).

After doing conversion - run the CLT iwfsshrink (run with -h flag for usage information). This finds redundant versions of data (where only things like file attributes were actually changed) and removes the redundant copy of the actual data - I've seend backing stores that have shrunk by as much as 60% from running this CLT after conversion. This is one of the major improvements in the 5.5.2 backing store.

--fish
(Interwoven Senior Technical Consultant)