bottlenecks are generally a mix of all them
if you are doing PST Exports you will see storageonlineopns take the most CPU , same with orphaned shortcut deletion
if you are doing update shortcut location (and retention category) you will see SQL start blocking excessively in some circumstances
if you are rebuilding indexes or get behind on your indexing, you will see a mix of IndexServer and StorageOnlineOpns take the most cpu time
If you are doing OSIS/Vault Store Sharing, you will see more network bandwidth being taken up
If your exchange isn't optimized disk wise, you will see long disk queues on the exchange server and possibly get warnings on end users machines from outlook saying that it is attempting to retrieve data.
If your SQL server isn't optimized disk wise, you will see long disk queues, and you will get excessive blocks as others are waiting on an IO Latch (i.e waiting for the disk to become free)
but if everything appears to be ok then you can do the following to help get things moving
Up your MAPI threads to more than 5 if you have few tasks
put storage server archiving processes to 10
make sure that update shortcut locations is turned off
make sure that orphaned shortcut deletion is turned off
put your site schedule to 24x7 with a gap of 15 minutes every 4-6 hours so that its not waiting with nothing to do
ensure that AntiVirus isn't scanning your temp directories, ev vault stores and your indexing location, MSMQ locations etc
make sure you have Outlook 2003 and not 2007 on your ev servers, as 2007 has decreased performance overall
Turn off monitoring for EV so you don't run in to costly SQL stored procedures like archivingperformancebyhours
for shortcuts, try and keep the characters as small as possible, don't put something crazy like 2 million as it could possibly hang the archiving process
Add things like EXE to the registry so as not to convert it
Make sure all the best practice registry keys are in place
up the MSMQ storage to 8GB from 1GB as if it breaches that limit, you wont get any warning from msmq or EV, things will just stop
Set the Profile Expiry in the registry to be 1 day instead of 3 as to stop any mapi mutex time outs
try and keep searches and pst exports to a minimum
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