we're currently on 6.7b-41. i guess we need to upgrade the code to get 
erec_show. that's something i'm a bit reluctant to do right now :-)

david camm
advanced web systems
keller, tx


On 3/18/2016 4:12 PM, surgemail-support wrote:
> The primary thing to grab is
>     tellmail status
> while the load is occurring, a couple of them would be good and send 
> along for me to look at.
>
> The other command in recent builds that can be useful is:
>
> tellmail erec_show
>
> which gives some useful information on which imap users are causing 
> the most 'load'.  this can help to identify an account that is sending 
> out thrashing
> imap commands (sometimes a bad client will just send the same request 
> endlessly)
>
>     ChrisP.
>
>
> On 19/03/2016 8:37 a.m., David Camm wrote:
>> we're running on a 4-core, 4G, raid5 machine running open suse linux.
>>
>> the kernel thinks we have 8 cores.
>>
>> under most circumstances,  surgemail just hums along with a load 
>> average anywhere from .5 to 4, which is just fine.
>>
>> several times lately, we've seen the load average spike to 10 or more 
>> and remain there for several minutes, at which point i stop 
>> surgemail, wait a bit and restart.
>>
>> what we've determined is that there's a HUGE amount of io activity 
>> occurring when this happens and the system becomes io-bound.
>>
>> we've tried running iotop, but that only tells us surgemail is 
>> writing a gazillion kb per second. not very helpful. examining the 
>> logs hasn't proved to be useful either.
>>
>> so.......
>>
>> is there any diagnostic we can run to determine what's happening and 
>> why there's such a huge io load?
>>
>> and, can anyone give some insight as to what situation might cause 
>> this to happen in the first place?
>>
>> btw - we're very conservative and limit email size to 20MB, so it 
>> can't be someone trying to receive a file with a 1GB attachment. it 
>> also can't be hackers attempting to log in, as that would just 
>> generate small writes to mail.err.
>>
>> david camm
>> advanced web systems
>> keller, tx
>>
>>
>>
>>
>
>
>