On Wed, May 17, 2006 at 09:20:58AM -0500, Jason L Tibbitts III wrote: > Has anyone given thought to automatically disabling compression on > filesystems where compression performs poorly? I have a large number > of filesystems to back up and my "compression ratio" should be an > "expansion ratio". There are some filesystems where it helps quite a > bit, however. Rather than turning it off globally I could disable it > on selected filesystems, but going through the whole list is time > consuming. > > Is it possible for amanda to consult the backup history and check the > past compression performance when deciding whether or not to enable > compression on a particular filesystem? > > Note: I'm willing to hack at this if someone can give me some > pointers. >
I don't think an automatic tool is needed. The compressibility of a DLE doesn't change often. However a tool to check and recommend might be useful. And it could be entended to take action automatically if desired. Things to consider/sources of input data: - curinfo directory has "info" file showing up to 3 most recent compression ratios for full and incremental. You could grep for these lines. - same data is available from amadmin "info" cmd in a different form. - amadmin "disklist" cmd can show whether compression is turned on. -- Jon H. LaBadie [EMAIL PROTECTED] JG Computing 4455 Province Line Road (609) 252-0159 Princeton, NJ 08540-4322 (609) 683-7220 (fax)
