Could a storage bottleneck be causing Microsoft Exchange server to be slow?
Applies to
- Microsoft Exchange Server
- ONTAP 9
- Data ONTAP 8 7-mode
Answer
- Typically, to determine if the performance issue is storage related, we need to determine if the Exchange host is seeing any latency from the Logical Unit Number (LUNs) that are mounted
- From the Exchange host use the
Perfmon
tool that is included in Windows. - Unless
Perfmon
is showing latency on those virtual disks, the performance issue is typically on the host and not the filer
Additional Information
- Please start a Perfmon session on the Exchange host and add the following counters:
PhysicalDisk\\Average Disk sec/Read
PhysicalDisk\\Average Disk sec/Write
PhysicalDisk\\Average Disk Queue Length
- Microsoft has defined the following guidelines for the functions that those disks serve as values for the counters:
Database |
|
||||||
Transaction Logs |
|
||||||
SMTP queues |
|
||||||
Page File Disk |
|
- Note: The page file disk should on local storage if it is not currently located there
- The following counters are not storage specific, but will provide information about how the host is processing Microsoft Exchange requests and help identify an Exchange issue:
Memory\\Available Mbytes (MB)
Memory\\Pages/sec
Processor\\% Processor Time (_Total)
System\\Processor Queue Length
Network Interface\\Bytes Total/sec
Network Interface\\Packets Outbound Errors
SMTP Server\\Categorizer Queue Length
MSExchangeDSAccess Process\\LDAP Read Time (for all processes)
MSExchangeDSAccess Process\\LDAP Search Time (for all processes)
- From the filer, use
qos statistics volume latency show
to check the performance compared to the Perfmon