Sony SDX-1100V Data Compression Transfer Log Page 39h Sony Unique, Length 58h, Parameter Code n

6.Command Specification LOG SENSE

6.6.11.Data Compression Transfer Log Page (39h) (Sony Unique)

The page allows the initiator to monitor the performance of the ALDC compression. The PC field in LOG SENSE determines whether current cumulative or current/default threshold values are returned. The page has the following format:

Table 6-34: Data Compression Transfer Log Page

Bit	7	6	5	4	3	2	1	0
Byte
0	Reserved				Page Code (39h)
1				Reserved
2	(MSB)			Page Length (58h)
3								(LSB)
4	(MSB)			Parameter Code (n)
5								(LSB)
6	DU (0)	DS (1)	TSD (0)	ETC (0)	TMC (00)		LBIN (0)	LP (0)
7				Parameter	Length (4)
8	(MSB)			Parameter Value
11								(LSB)

Data Compression Log Page Fields:

Supported Parameter Codes in this page and their meanings are as follows:

Code	Description	Length
0001h	Number of entities written	4
0002h	Number of entities read	4
0003h	Number of records written	4
0004h	Number of records read	4
0005h	Megabytes to data compression	4
0006h	Megabytes from data compression	4
0007h	Megabytes to tape	4
0008h	Megabytes from tape	4
0009h	Logical entity size	4
000Ah	Physical entity size	4
000Bh	Uncompressed entities	4

Entities Written/Read: The total number of complete entities written to or read from the tape since the last power-on or Clear Log operation.

Records Written/Read: The total number of records (both compressed and uncompressed) written to or read from the tape since the last power-on or Clear Log operation.

Kilobytes to/from Data Compression: The total number of kilobytes written to or read from the tape since the last power-on or Clear Log operation. For Kilobytes from Data Compression, this number may be greater than the number of kilobytes transferred to the initiator due to read ahead.

Logical Entity Size: The logical size of the last entity written to or read from the tape: size = number of record in entity ⋅ record size in bytes

Physical Entity Size: The physical size of the last entity written to or read from the tape: size = entity header length + uncompressed data length

Uncompressed Entities: The total number of times non-ALDC entities have been encountered on the tape during read operations since the last power-on or Clear Log operation.

6-30 SONY AIT-5 drive SDX-1100V series Ver.1.0