Setting up IO fencing on HPIA64

Use these steps to configure an HPIA64 system for a cluster environment. HP Integrity VM is not supported in ESD #4.

To confirm whether a disk is IO fencing capable, run the qrmutil utility at $SYBASE/$SYBASE_ASE/bin/qrmutil.

The following table provides a list of what is and is not supported with IO fencing for HPIA64.

Supported	Not supported
Character devices, such as /dev/rdsk/c5t11d0	Block devices, such as /dev/dsk/c5t11d0
Legacy DSF on HPIA64	Persistent DSF on HP-UX 11.31
	VxVM devices or HP LVM devices
	Raw devices under /dev/vx/rdsk

To avoid unexpected results, Sybase recommends that you not create any volume groups on these disks, but instead keep them “free” by not configuring the disks as a part of volume groups or other disk management software, and ensuring that no other software is running on the machine.

Set privileges:

Change the owner of all the devices that you plan to use as shared database devices to “sybase”. For example, if you plan to use the device /dev/rdsk/c5t11d0 for Adaptive Servershared database device, then change the owner of /dev/rdsk/c5t11d0 to “sybase” with:
```
# chown sybase /dev/rdsk/c5t11d0
```
Change the access permission of the devices with:
```
# chmod 660 /dev/rdsk/c5t11d0
```

Sybase recommands that you delete any previously existing devices in /dev/raw before creating the pass-through device.

# rm -rf /dev/raw/*

Create the pass-through device special file:

To create the pass-through device special file for all the shared database devices you plan to use with IO fencing, run the mknod command:
```
# mknod /dev/raw/raw# c 203 <minor>
```
Where:
- /dev/raw/raw# – is the name of the newly created pass-through device special file. “#” can be any number, but you cannot change the path.
- c – specifies that you are creating a character device.
- 203 – specifies that you are attaching the pass-through device driver to this device.
- <minor> – is the minor number of the specified shared-database device. Its format is 0xiitl0o.
  - ii – is two hexadecimal digits that identify the controlling interface card by its “instance” number.
  - t – is one hexadecimal digit that identifies the drive (target) address.
  - l – is one dexadecimal digit that identifies the logical unit number (LUN) within the device.
  - 0 – is the hexadecimal digit zero, for the reserved portion of the minor number.
  - o – is for optional values: 0 to perform inquiry on open to ensure the device exists (recommended); or 2 to inhibit inquiry on open.
  To obtain the value of 0xiitl0o, enter:
```
ls -l device_name
```
  For example, for device “/dev/rdsk/c5t11d0”, enter:
```
ls -l /dev/rdsk/c5t11d0
```
  The output is:
```
crwxrwxrwx 1 bin sys 188 0x05b000 Oct 14 09:33 /dev/rdsk/c5t11d0
```
  The value of 0xiitl0o is the first 16 bits of “0x05b000”, reading from the left.
  
  The mknod command on the devices /dev/rdsk/c5t11d0 and /dev/rdsk/c5t12d0 would look like the following, with “raw1” and “raw2” indicating the two devices:
```
# mknod /dev/raw/raw1 c 203 0x05b000
# mknod /dev/raw/raw2 c 203 0x05c000
```
  For disk partitions, only one pass-through device special file is needed. For example, suppose there are five partitions for /dev/rdsk/c5t11d0: /dev/rdsk/c5d11d0s1 ~ /dev/rdsk/c5d11d0s5. Because these partitions all have the same minor number, the command to create the pass-through device special file for all of them is:
```
# mknod /dev/raw/raw1 c 203 0x05b000
```

To avoid the potential security issue, you can change the commands to:

# chown sybase /dev/raw/raw1
# chown sybase /dev/raw/raw2
# chown 660 /dev/raw/raw1
# chown 660 /dev/raw/raw2

Repeat this process for any additional shared-disk devices you plan to use.