Exchange backup very slow
Hi, my master server is NBU 7.1 on Windows 2008 R2 SP1. We have two Exchange 2010 mailbox servers (both are Exchange 2010 SP1 on Windows 2008 R2 SP1). We have converted both mailbox servers to SAN media servers and connected them to the tape library (LTO4 FC tape drive) via FC.
When we do backups, it take very long to complete the backups. For example, we have one mailboxDB1 on mailbox server A. The size of the mailboxDB1 is about 500GB. It took about 2 hrs for the backup to start to actual write data to the tape. From activity monitor, it said the backup starts but then just hang there. After about 1 hrs, it start a sub job which shows file list of the mailbox DB. After another 1 hrs, it starts to write data on the tape.And the backup throughput is less than 10MB/s (normally only 7 ~ 8MB/s).
As the connection from the mailbox server to the tape drive is FC, we expect the throughput to be 30 ~40MB/s at least. May I know how to troubleshoot this? Thanks in advance.