Help Needed: Exchange 2010 Backup problem
I'm starting to bang my head on the wall on this... :-/
I have an Exchange 2010 running on a 2008R2 virtual server. Two months ago we started switching from Blackberries to Android (Samsung S5 mini). Each smartphone is configured with an Exchange account, and work properly in daily use, but at system level I can observe that:
- transaction logs have increased to almost tenfold size
- backup times have gone from about 3 hours to almost 9
- database growth is normal, and not even comparable to daily trasaction logs' size
Using ExMon and MS's IS log analyzer I couldn't find any particular culprit mailbox (with stuck messages, corrupted events, and similar problems), but I see a LOT of ActiveSync activity coming from all the Android clients.
My current hypothesis is that ActiveSync is using a lot of Ping, Sync and FolderSync commands, which dirty the database pages, although they don't cause an increase of their size. This would explain why backup now takes ages: because it has to rewrite a lot of pages, whereas before Android it would skip most of the writes since a lot of blocks would be identical to the previous backup.
But this is just an hypothesis, since we are in black magic area here, and I cannot find anything to confirm my ideas.
I know that in the past iDevices could bring an Exchange server to a crawl, but that has long been fixed, and TBH the few iDevices which are connected through ActiveSync are using far less resources than the average Samsung.
There are also some non S5 mini Android devices attached via Active Sync, and they generate a similar activity.
The two mail databases sum up to almost 400GB, of which about 80GB are free. I will try to move all mailboxes to new databases, in order to recompact them without turning off the server, but my feeling is that there is something wrong which will only be alleviated by a DB size reduction.
If you can point me to some article which can throw light on this problem, you'll save a wall from being smashed by my head :-)