Is it safe to delete the old cumulative update directories from the %ProgramFiles%\Microsoft SQL Server\110\Setup Bootstrap\Update Cache folders?
At least this MSDN blog post tells to leave anything in place in this directory. Is there any reference or supportability statement anywhere telling that I could or must not do that?
Rationale:
Due to the infamous "incremental service model" for SQL Server, the SP1 for SQL Server 2012 has so far seen 9 cumulative update releases. The Update Cache directory is growing with each CU install and in environments where each CU since SP1 has been installed, it is at 9 GB already. We have the prospect of adding another 3 GB for the next 3 CU releases before the next SP is out "later this year". Since the updates are "cumulative" I am trying to determine if it would be safe to delete all but the latest cumulative update directory from the Update Cache.
For a single server I probably would not bother, but the storage team members (who have not managed to implement storage-based deduplication yet) are crying frequently because of the growing storage requirements for SQL server instances and my office's carpet is soaking wet already.
No, it is not: https://support.microsoft.com/en-us/kb/969052/en-us
I ran into something similar on a Windows XP machine when deleting Windows Update files, and essentially broke my .NET installation in a way that required a full reinstall to correct.
I saw another person on the Microsoft forums who was planning to offload the files to a SAN for day-to-day performance improvement, then move them back incrementally if updates failed. They didn't provide a follow-up with success or failure messages, however.