Dell PowerVault ML6000 Dell PowerVault ML6000 SCSI Reference Guide - Page 60

Read Reservations Response, RESERVE OUT command.

Get Dell PowerVault ML6000 PDF manuals and user guides View all Dell PowerVault ML6000 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 60 highlights

Read Reservations Response The response for a Read Reservations service action is shown in the following table. Table 47 Read Reservations Response Byte Bit 7 6 5 4 3 2 1 0 0 Generation 3 4 Additional Length (0010h) 7 Reservation Descriptor 8 Reservation Key 15 16 Scope-Specific Address 19 20 Reserved 21 Scope Type 22 Obsolete 23 Generation - This field is a 32-bit counter that is incremented every time a PERSISTENT RESERVE OUT command requests a Register, a Register and Ignore Existing Key, a Clear, a Preempt, or a Preempt and Abort service action. This counter is not maintained across power cycles. Additional Length - This field indicates the length in bytes of the Reservation Descriptor, and returns 0010h (16). Since element reservations are not supported, a single reservation descriptor is returned for logical unit. Reservation Key - This is the 8-byte reservation key that was registered through the PERSISTENT RESERVE OUT command. Scope-Specific Address - Element reservations are not supported and this field returns 0000h. Scope - This field returns a 0h, indicating logical unit scope. Element scope is not supported. Type - This field returns the type of reservation as follows: • 3h Exclusive Access - The initiator holding the persistent reservation has exclusive read and write access. Requests from any other initiators to transfer data to or from the logical unit will result in a Reservation Conflict. • 6h Exclusive Access, Registrants Only - Any currently registered initiator has exclusive data transfer access. Requests from unregistered initiators to transfer data to or from the logical unit will result in a Reservation Conflict. 50 SCSI Commands

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
50
SCSI Commands
Read Reservations Response
The response for a Read Reservations service action is shown in the following table.
Generation
– This field is a 32-bit counter that is incremented every time a PERSISTENT RESERVE OUT
command requests a Register, a Register and Ignore Existing Key, a Clear, a Preempt, or a Preempt and
Abort service action. This counter is not maintained across power cycles.
Additional Length
– This field indicates the length in bytes of the Reservation Descriptor, and returns
0010h (16).
Since element reservations are not supported, a single reservation descriptor is returned for logical unit.
Reservation Key
– This is the 8-byte reservation key that was registered through the PERSISTENT
RESERVE OUT command.
Scope-Specific Address
– Element reservations are not supported and this field returns 0000h.
Scope
– This field returns a 0h, indicating logical unit scope. Element scope is not supported.
Type
– This field returns the type of reservation as follows:
•
3h
Exclusive Access – The initiator holding the persistent reservation has exclusive read and write
access. Requests from any other initiators to transfer data to or from the logical unit will result in a
Reservation Conflict.
•
6h
Exclusive Access, Registrants Only – Any currently registered initiator has exclusive data
transfer access. Requests from unregistered initiators to transfer data to or from the logical unit will
result in a Reservation Conflict.
Table 47
Read Reservations Response
Bit
Byte
7
6
5
4
3
2
1
0
0
Generation
3
4
Additional Length (0010h)
7
Reservation Descriptor
8
Reservation Key
15
16
Scope-Specific Address
19
20
Reserved
21
Scope
Type
22
Obsolete
23