Oracle StorageTek T10000

Read Buffer Command
156 T10000: Interface Reference Manual August 2016
Read Buffer Command
The Read Buffer Command retrieves trace dump data. Any buffered write data and
filemarks are written on the tape before this operation starts.
Notes:
• The tape drive must be unloaded when reading dump, permanent error trace,
or event log data. The minimum allocation length is 4096 bytes.
• Multiple Read Buffer commands may be required to read the entire contents of
a particular buffer. Blocks of data are transferred in sequential order. Blocks of
data may be truncated, this does not signify the end of the transfer, continuing
transfer data blocks until Blank Check is returned. All Read Buffer commands
needed to read a complete buffer must use the same allocation length. The
sequence of read buffer commands required to read a complete buffer should
continue uninterrupted until a sense key of Blank Check is returned.
TABLE 3-109 Read Buffer Command
Byte
Bit
76543210
0 Operation Code (3Ch)
1 Reserved Mode
2 Buffer ID
3
thru
5
(MSB)
Buffer Offset
(LSB)
6
thru
8
(MSB)
Allocation Length
(LSB)
9 Vendor–specific Reserved Flag Link
Parameter Value
Mode Read buffer mode
01h = Vendor-specific
03h = Descriptor
0Ah = Echo buffer
0Bh = Echo buffer descriptor
Buffer ID FAh = MIR position data
FCh = MIR performance data (not on T10000C and T10000D)
FDh = Permanent error trace data
FEh = Event log data (not on T10000C)
FFh = Dump buffer
Buffer Offset Offset from start of buffer (this field is ignored, except for
Mode 0Ah on T10000D and newer drives)
Allocation Length Maximum length of dump data to transfer