I've been trying to get the answers to your questions. Sorry it's taking some time. It's been a while now so I thought I'd let you know what I have so far although it is incomplete.
We have four vault stores. The problem has been reported by some but by no means all users with archives on all of these.
None of the servers looks too busy during the day.
There is plenty in the event logs on all four EV servers. Nothing seems to correspond in time to failed attempts to do Store in Vault, however. There are a couple of recurring events that are vague enough to make me wonder if they're connected, though:
3430 A request has been made to restart all the MAPI tasks. There was a MAPI error from which Enterprise Vault cannot recover without restarting the tasks.
41521 Enterprise Vault Search cannot perform certain operations. Check that all Enterprise Vault services are running. Average one or two a day.
Unfortunately I can't see in the event log "Veritas Enterprise Vault" what MAPI error it cannot recover from, and any time I check, all Enterprise Vault services are running.
I did find an article (100013533) about 3430s every 15 minutes but these are not as often as that:
Server
|
How many 3430s
|
How many 41521s
|
Over how many days
|
Ev1
|
132
|
117
|
48
|
Ev2
|
146
|
105
|
37
|
Ev3
|
40
|
50
|
51
|
Ev4
|
84
|
213
|
69
|
I have checked the client log for one that gets the failure, and there is something there:
27/05/2021 09:45:32.287[117472][H]: User initiated manual archive action
27/05/2021 09:45:36.667[128996][H]: HTTP request error: 366 (503)
27/05/2021 09:45:36.668[128996][H]: Connect failed: 0x80004005
27/05/2021 09:46:12.928[138320][H]: Successfully contacted the EV web server using: http://*******/EnterpriseVault
27/05/2021 09:50:18.285[117472][H]: User initiated manual archive action
27/05/2021 09:50:26.065[154372][H]: HTTP request error: 366 (503)
27/05/2021 09:50:26.066[154372][H]: Connect failed: 0x80004005
27/05/2021 09:55:19.189[117472][H]: User initiated manual archive action
27/05/2021 09:55:21.804[171744][H]: HTTP request error: 366 (503)
27/05/2021 09:55:21.804[171744][H]: Connect failed: 0x80004005
Thanks for reading this. I'll post answers to your other questions when I have them.