Microsoft Exchange Performance Counters

Microsoft Exchange Mailbox Server Passive Database Copy IO Latency Requirements counters

The following table shows passive database copy I/O latency requirements counters. When these values are exceeded, the database copy may lag by not replaying logs to the passive database copy fast enough. Log replication performance may also be affected.

Counter Name	Description
Database\Database Page Fault Stalls/sec
MSExchange Database\I/O Database Reads (Recovery) Average Latency	Indicates the average time, in ms, to read from the database file.
MSExchange Database\I/O Database Writes (Recovery) Average Latency	Indicates the average time, in ms, to write to the database file.