Dell PowerVault TL4000 - Manual (Page 26)

Allocation Length:
The Allocation Length field is used to inform the target how much space the initiator has allocated
for data. The target returns the bytes specified by allocation length.
Log Page Header format
Each Log Sense page begins with a 4-byte header.
Bit 7 6 5 4 3 2 1 0
Byte
0 Reserved Page Code
1 Reserved
2 - 3 Page Length
Field descriptions:
Page Code:
The Page Code echoes the page code that was specified in the CDB.
Page Length:
The Page Length specifies the total number of bytes contained in this log page, not including the
four bytes of the header.
Supported Pages Log Page (00h)
When page 0 is requested, the 4-byte page header is returned followed by the pages supported in
ascending order, one byte for each page.
Bit 7 6 5 4 3 2 1 0
Byte
0 Reserved Page Code (00h)
1 Reserved
2 - 3 Page Length (5)
4 00h - Supported Log Pages page
5 07h - Event Log page
6 2Eh - Tape Alert page
7 30h - Statistics Counter page
8 33h - Error Log page
Event Log Page (07h)
In the Event Log the media changer keeps track of different system events. These events exist out of
hardware errors, executed commands, and debug information. The events are stored in a FIFO mode, this
means that only the n most recent events are stored. Older events are deleted. This log is stored in non
volatile memory (NVRAM) and is therefore resistant to power failures.
The data returned for the Event log page shall not exceed 64KBytes. A single LOG SENSE command to
the Event Log page may return all events. The Event Log page starts with a header indicating the number
of bytes of the total event history, followed by zero or more event structures. Reading the Event Log page
shall not clear the event data. Clearing the event data is done by means of the LOG SELECT command.
Note: The Host may specify what event types need to be logged. This is done with the MODE SELECT
command to the vendor specific Event Filter page.
3-12 TL2000 and TL4000 SCSI Reference