Bare-Metal Restore is Slow in GB LAN
Symptom
We are doing a Bare-Metal Restore on our GB LAN. The transfer speed rarely goes up above 20 Mbit/s. The host CPU usage is only about 10%. The compression is set to "9" (best).
Resolution
To diagnose the problem, follow the instructions below.
1. Try a large file copy from/to Boot CD / CDP Server.
This may occur if the NIC on the Boot CD is negotiated as half-duplex which is not uncommon on gigabit LANs. Usually NIC is set to autonegotiate the speed and duplex mode, and this mode is selected based on switch capabilities and signal strength. Selecting 1Gbps full-duplex requires maximum capabilities from the switches and minimum electrical noise in the cable. If, for example, cable is too long, or there are a lot of electrical disturbances (power cable located nearby), NIC may negotiate a half-duplex mode. In half-duplex mode it cannot transmit and recieve data at the same time, which results in lowering the data throughput.
To start SSH from the Boot CD:
From Windows / Linux CPD Server:
For Windows CDP Server:
Use Putty scp client pscp.exe to copy large files in both directions from the CDP Server.
For Linux CDP Server:
You can do all of the pscp from the Boot CD, so you don't have to bother with logging into the Boot CD.
2. Check if you are running any backup jobs on the CDP Server during the restore.
Note: Level 9 compression adds a tremendous amount of CPU usage during backup on the Agent in exchange for only marginally better compression. We would recommend level 1.