ATTO Technology 2700C - Manual (Page 29)

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same machine. Check with the vendors to
make sure they are compatible.
2 Verify that the PC has the latest iSCSI driver as
well as the required service packs and patches.
Check with the iSCSI OS driver vendor for more
information.
3 Verify that the iSCSI OS driver has started.
Look under Device Manager for Windows or
lsmod for Linux.
4 Verify that the iSCSI OS is still looking for the
iPBridge at the right IP address.
5 If using DHCP, verify that the DHCP server is
assigning the correct IP information to the host.
6 Verify that the NIC is configured with the correct
IP information.
7 Verify that the hosts and the iPBridge are using
the same port number to communicate iSCSI
on the ATTO ExpressNAV iSCSI page. The
default port number for the iPBridge is 3260.
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.
Check 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.
Check the applications
1 Verify that the application is running the latest
device drivers for the devices connected to
iPBridge. 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.
Check Fibre Channel devices
Verify that the devices are running at their highest
possible speed. Refer to
FCDataRate on page vii
of the Appendix.
Check the iPBridge Ethernet ports
1 Verify that the data port is set to auto negotiate
or forced to 1000 Mb/sec. on the ExpressNAV
Ethernet page.
2 Verify that the MTU size is set to optimal setting
for the LAN/WAN environment. 9k frame size is
the current optimized frame size for the
iPBridge.
3 Verify that the iPBridge TraceLog feature is
disabled. Tracelog tracks certain events that
occur in the iPBridge. With this log enabled,
performance suffers. Refer to
TraceLog on
page xii of the Appendix.
Check the LAN/WAN
1 Verify that the MTU size is set to optimal setting
for the LAN/WAN environment on the ATTO
ExpressNAV Ethernet page.
9k frame size is the current optimized frame
size for the iPBridge. Many switch and router
vendors do not support the larger frame size of
9k or 16k.
2 Verify that each associated port in the IP SAN
is configured for 1000Mbs.
IP SAN traffic should be segmented so that it
does not interfere with the main LAN network
traffic.For better performance, the IP SAN
should be on its own set of hardware.
3 Verify that packets are not being dropped along
the LAN/WAN. Many utilities track packet
activity and switch statistics.
Check the Ethernet host adapter or NIC
Ethernet storage adapters generally outperform
accelerated NICs and un-accelerated NICs by
offloading most of the processing from the host.
An accelerated NIC provides some offloading,
but still requires a host OS iSCSI driver, making
the host spend more CPU cycles.