6.4.3 Determining the values to be specified in the operands required for SCSI reservation of the shared disk if LVM is not used

This section describes how to obtain the values to be specified in the scsi_device and dmmp_device operands in the server environment definition if LVM is not used.

Specify the scsi_device operand in the following cases:

A single-path configuration is used.
A VMware ESXi-based virtualization environment is used (except when DMMP is used).

If you use a redundant configuration with multipath software (DMMP), specify the dmmp_device operand.

Organization of this subsection

(1) Value to be specified in the scsi_device operand
(2) dmmp_device operand value (redundant configuration using multipath software (DMMP))

(1) Value to be specified in the scsi_device operand

(a) If HFC-PCM is used with a single-path configuration in a VMware ESXi-based virtualization environment

Specify in the scsi_device operand the symbolic link for the shared disk. You can determine the symbolic link to the shared disk from the device name of the file system.

The following describes the procedures for determining the value to be specified in the scsi_device operand in two cases: the case where the file system is located on a device (no partition is created); and the case where the file system is located in a partition (partitions are created).

Case where the file system is located on a device (no partition is created)

To determine the value to be specified in the scsi_device operand:
1. Check the device name.
  
  Check the device name by specifying the file system UUID in the following command. For UUID, specify the value obtained by removing /dev/disk/by-uuid/ from the value specified for the fs_name operand.
```
# findfs UUID=uuid
```
  The following shows an example in which you specify c73bf13f-89a9-49bc-9d8d-7c94e5458389 for UUID.
  
  Example:
```
# findfs UUID=c73bf13f-89a9-49bc-9d8d-7c94e5458389
```
  Execution results:
```
/dev/sda
```
  The underlined portion is the device name.
2. Obtain the symbolic link.
  
  Use the command below to obtain the symbolic link that is located under /dev/disk/by-id and that is created by the OS. Remove the string /dev/ from the device name that was obtained in step 1. The resulting string is the device name to specify in the command.
```
# ls -l /dev/disk/by-id | grep device-name
```
  The following shows an example when you specify sda as the device name.
  
  Example:
```
# ls -l /dev/disk/by-id | grep sda
```
  Execution results:
```
lrwxrwxrwx 1 root root  9  Jan  7 11:03 scsi-360060e8010462fe004f2b6ae00000027 -> ../../sda
lrwxrwxrwx 1 root root  9  Jan  7 11:03 wwn-0x60060e8010462fe004f2b6ae00000027 -> ../../sda
```
  The underlined portion is a symbolic link. In the scsi_device operand, specify an absolute path.
  
  Example of setting the scsi_device operand:
```
scsi_device  /dev/disk/by-id/scsi-360060e8010462fe004f2b6ae00000027
```
  Notes
  
  Do not specify the following symbolic links for the scsi_device operand:
  
  • A symbolic link that ends with part
  
  • A symbolic link that begins with wwn-
Case where the file system is located in a partition (partitions are created)

To determine the value to be specified in the scsi_device operand:
1. Check the device name.
  
  Check the device name by specifying the file system UUID in the following command. For UUID, specify the value obtained by removing /dev/disk/by-uuid/ from the value specified for the fs_name operand.
```
# findfs UUID=uuid
```
  The following shows an example in which you specify af306d54-8907-471f-9119-3b68dabbc9bd for UUID.
  
  Example:
```
# findfs UUID=af306d54-8907-471f-9119-3b68dabbc9bd
```
  Execution results:
```
/dev/sda1
```
  The underlined portion is the device name. 1 at the end of the device name is the partition number.
2. Obtain the symbolic link.
  
  Use the command below to obtain the symbolic link that is located under /dev/disk/by-id and that is created by the OS. Remove the string /dev/ and the partition number from the device name that was obtained in step 1. The resulting string is the device name to specify in the command.
```
# ls -l /dev/disk/by-id | grep device-name$
```
  The following shows an example when you specify sda as the device name.
  
  Example:
```
# ls -l /dev/disk/by-id | grep sda$
```
  Execution results:
```
lrwxrwxrwx 1 root root  9  Jan  5 14:38 scsi-360060e8010462fe004f2b6ae00000035 -> ../../sda
lrwxrwxrwx 1 root root  9  Jan  5 14:38 wwn-0x60060e8010462fe004f2b6ae00000035 -> ../../sda
```
  The underlined portion is a symbolic link. In the scsi_device operand, specify an absolute path.
  
  Example of setting the scsi_device operand:
```
scsi_device  /dev/disk/by-id/scsi-360060e8010462fe004f2b6ae00000035
```
  Notes
  
  Do not specify the following symbolic links for the scsi_device operand:
  
  • A symbolic link that ends with part
  
  • A symbolic link that begins with wwn-

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(2) dmmp_device operand value (redundant configuration using multipath software (DMMP))

Specify in the dmmp_device operand the absolute path of the DMMP's logical device. Obtain the logical device name from the UUID that was specified in the fs_name operand.

Check the device name by specifying the file system UUID in the following command. For UUID, specify the value obtained by removing /dev/disk/by-uuid/ from the value specified for the fs_name operand.

# findfs UUID=uuid

The following shows an example in which you specify dfed18bb-0271-400d-9b8c-bc78c41f0b28 for UUID.

Example:

# findfs UUID=dfed18bb-0271-400d-9b8c-bc78c41f0b28

Execution results:

/dev/mapper/mpatha1p1

The underlined portion is the device name. p1 at the end is the partition number.

Remove the partition number from the logical device name, and then specify the resulting string for the dmmp_device operand.

Example of setting the dmmp_device operand:

dmmp_device /dev/mapper/mpatha1

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