Quantum SNC 4500, Руководство пользователя

Страница: 54 / 122

48 Troubleshooting
4 Verify that the iSCSI OS is still looking for the SNC at the right IP address.
5 If using DHCP, verify that the DHCP server is assigning the correct IP information to the host. Refer to
Ethernet Ports on page 4.
6 Verify that the NIC is configured with the correct IP information.
7 Verify that the hosts and the SNC are using the same port number to communicate iSCSI. The default
port number for the SNC is 3260. Refer to
get iSCSIPortNumber on page 70.
8 Check cable integrity. Check the cables for solid connections. Make sure they are plugged in properly.
Inspect cable ends for broken clips and improper wiring.
Checking the Operating System
1 Verify that the OS has the required service packs or patches installed. If not, obtain the proper service
packs and patches and install them.
2 Some iSCSI host adapters and iSCSI OS drivers do not always automatically find new targets when
plugged in or when forced to rescan. Reboot the hosts.
3 Check if the vendor has a new driver. If so, install it.
Checking the Applications
1 Verify that the application is running the latest device drivers for the devices connected to SNC. If not,
get the latest device drivers and install them.
2 Verify with the application vendor if the iSCSI technology is supported on the version of the application
being used.
Performance Issues
If the host is not getting the performance it should, check the following items.
Checking SCSI Devices
1 Verify that the devices are running at their highest possible SCSI speed. Refer to SCSI Configuration
Commands on page 54.
Mixing SE and LVD devices on the same SCSI bus forces the speed of the bus to SE, thus slowing
faster LVD devices. The SNC cannot accelerate an already slow device. Refer to
Connecting to the
Serial Port on page 18.
2 Verify that the proper terminator is being used. An SE terminator forces the SCSI bus to SE speeds.
Checking the SNC SCSI Ports
1 Verify that the SCSI port configuration is set to the highest speed using the SNC Manager interface or
CLI. Refer to
SCSI Configuration Commands on page 54.
The SNC SCSI port speed, wide negotiation, and sync negotiation settings all affect the speed of the
port. By default, these settings are set for optimal speed.
2 Verify that the SCSI devices are equally distributed between the SCSI ports. Refer to Connecting to the
Serial Port on page 18. Optimal performance is seen when only two high-speed SCSI devices are
connected to each SCSI port.