Using udev with st devices – Dell Emulex Family of Adapters User Manual

Page 832

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Emulex Drivers Version 10.2 for Linux User Manual

P010081-01A Rev. A

3. Configuration

FC and FCoE Driver Configuration

832

Configuring the System to Boot Using Persistent Names

For SLES 11 SPx

Note: SLES 11 SPx is configured by default with udev to provide persistent names for

hard disks, including FC-attached disks.

To use a persistent name for a boot device with SLES 11 SPx:
1. In /boot/grub/menu.lst, find the kernel line for the default boot. For example:

kernel /boot/vmlinuz root=/dev/sda2 vga=0x314

2. Find the persistent name for the root partition (following “root=” on the kernel line)

by using the instructions in “Using udev to Discover Logical to Physical Mappings

for sd Devices” on page 831.

3. In the same file, /boot/grub/menu.lst, replace the text after “root=” with the

partition’s persistent name. For example:

kernel /boot/vmlinuz root=/dev/disk/by-id/scsi-32000000c5005d6e6-part2

vga=0x314

4. Change any mounts listed in /etc/fstab that refer to this root partition by either its

/dev/sd name or a file system label to use the persistent name as well.

For RHEL 5.x and RHEL 6.x

To use a persistent name for a boot device with RHEL 5.x and RHEL 6.x:
1. In /boot/grub/grub.conf, find the kernel line for the default boot. For example:

kernel /boot/vmlinuz -<kernel version> ro root=/dev/sda2

2. Find the persistent name for the root partition (following “root=” on the kernel line)

by using the instructions in “Using udev to Discover Logical to Physical Mappings

for sd Devices” on page 831.

3. In the same file, /boot/grub/menu.lst, replace the text after “root=” with the

partition's persistent name. For example:

kernel /boot/vmlinuz -<kernel version> ro

root=/dev/disk/by-id/scsi-32000000c5005d6e6-part2

4. Change any mounts listed in /etc/fstab which refer to this root partition by either

its /dev/sd name or a file system label to use the persistent name as well.

Using udev with st Devices

In Linux, the driver for SCSI tape drives is “st”. A tape device name has an “st” prefix.

The udev rules for tape devices are the same as for disk devices. There must be a

unique ID that persists across initiator reboots and persists regardless of discovery

order.
You must consider whether the tape device is an FC tape device or an FC-SCSI tape

device (in which there are multiple SCSI tape devices that reside behind an FC

controller). If it is an FC tape device, then the WWPN is unique and can be used to

create the persistent name. In this case, the scsi_id command should return this as the

unique identifier with a single digit prefix. If the FC controller has multiple SCSI tape

devices behind it, the WWPN is not unique, and the persistent name must use multiple

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