Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
267
18.46
VERIFY (10) - (2F)
Table 250 VERIFY (10) - (2F)
Byte
Bit
7
6
5
4
3
2
1
0
0
Command Code = 2Fh
1
VRPROTECT DPO
RSVD
= 0
ByteChk RSVD = 0
2-5
(MSB)
Logical Block Address
(LSB)
6
Reserved = 0
7-8
(MSB)
Verification Length
(LSB)
9
VU = 0
Reserved = 0
FLAG
LINK
The VERIFY command requests that the drive verify the data written on the media. A verification length of zero
indicates that no data will be transferred. This condition is not considered an error.
Table 251 Byte Check
ByteChk Function
00b
Indicates that the data is read from the disk and verified using LDPC. If an LDPC
error is detected in the verify process, Check Condition status is returned with
sense key set to Medium Error.
01b
Indicates that a byte-by-byte comparison is performed between the data on the
disk and data transferred from the initiator during the data-out phase. The
number of logical blocks transferred must equal the Verification Length field. If
the comparison is unsuccessful, the command is terminated with Check
Condition status and the sense key is set to Miscompare.
10b
Not defined
11b
Indicates that a byte-by-byte comparison is performed between the data on the
disk and data transferred from the initiator during the data-out phase. The
number of logical blocks transferred must equal one. All blocks specified by the
Verification Length will be compared against the single block of data transferred
by the initiator. If the comparison is unsuccessful, the command is terminated
with Check Condition status and the sense key is set to Miscompare.
- DPO (Disable Page Out) bit of one indicates that the data accessed by this command is to be assigned the
lowest priority for being written into or retained by the cache. A DPO bit of one overrides any retention priority
specified in the Mode Select Page 8 Caching Parameters. A DPO bit of zero indicates the priority is determined
by the retention priority. The Initiator should set the DPO bit when the blocks read by this command are not
likely to be read again in the near future.
If caching is enabled, the command performs an implied FUA and an implied Synchronize Cache before starting the
VERIFY. This ensures that the medium, not the cache, is being verified.
The command stops on Check Condition and reports the LBA in error. The command must be reissued, starting with
the next LBA, to verify the remainder of the Drive.