Dell PowerVault ML6000 - Manual (Page 71)

PowerVault ML6000 SCSI Reference Guide 61
Element Status Page
Each element status page consists of an eight-byte header, followed by one or more element descriptor
blocks. One Element Status Page header is returned for each grouping of element descriptor blocks, by
element type. The format of the Element Status Page header is shown in the following table.
Element Type Code – This field indicates the specific element type being returned by the element
descriptors for this page.
PVolTag – A value of one indicates that the primary volume tag field (barcode label) is present in each of
the element descriptor blocks that follow. A value of zero indicates that they are not present.
AVolTag – Alternate Volume Tags are not supported. The returned value for this field is 0, and the alternate
volume tag fields are omitted from the element descriptors.
Element Descriptor Length – This field indicates the number of bytes contained in a single element
descriptor. Refer to the individual element descriptor descriptions for each element type for their respective
possible lengths.
Byte Count of Descriptor Data Available – This field indicates the number of element descriptor data
bytes available for the elements of this element type that meet the CDB requirements. This value represents
the Element Descriptor Length field multiplied by the number of element descriptors for this element type.
This value does not include the 8-byte Element Status Page header, nor is it adjusted to match the allocation
length.
Element Descriptors
The following sections contain the definitions for the following element descriptors:
• Medium transport element
• Storage elements
• Import/Export elements
• Data transfer elements
Each element descriptor includes the element address, status flags, source storage element address, and
barcode label. Some descriptors also contain extended status information. Additional sense code and
qualifier information depends on the element type.
Table 60 Element Status Page
Bit
Byte
7 6 5 4 3 2 1 0
0 Element Type Code
1 PVolTag AVolTag Reserved
2
Element Descriptor Length
3
4 Reserved
5
Byte Count of Descriptor Data Available
7