Quantum Scalar i2000, Руководство пользователя

Страница: 108 / 120

100 Troubleshooting the SAN
Checking the Command Flow Log
Two kinds of events are recorded in the command flow log (CFL) file: sequence events and single command
events. Sequence events are Read/Write commands. All other events are single command events. You can
retrieve the CFL log file for use as a diagnostic tool.
Not all appliances in the SAN are capable of providing CFL data. If the appliance you select is not capable
of communicating this information, Command Flow Log does not appear on the appliance menu.
1 Right-click an appliance in the navigation panel or the graphical panel.
2 Select Command Flow Log .
The system attempts to log the user on to the SNC FTP server. If no default logon account is found, the
user is prompted to enter logon credentials. After you have logged on, the
Save Command Flow Log
dialog box is displayed.
3 Navigate to the location you want to save the log to. Enter a filename.
4 Click Save .
The number of bytes being saved is shown and is updated periodically until the entire file is saved.
5 Open the log file with a text editor.
Interpreting CFL Output
SCSI commands flow through SNCs connected to tape libraries. These commands are logged in command
flow log (CFL) areas on the SNC. CFLs exist for each target, including the SNC, up to a maximum of 10
targets. The following information is recorded in the CFL:
• LUN number of the device for which information is being provided.
• Device’s vendor, product ID, and serial number
• Month, day of the month, start time
• Initiator channel, initiator index
• Event name
• Number of times the SNC carried out the event
• Number of errors recorded in the course of the event being carried out
• Direction of data transfer (to or from the host)
• Number of bytes actually transferred
• Operation code
• Command descriptor block
• Command completion status
• End time