install details

1: AoE target

While the standard CentOS kernels seem to do so, it is worth first checking whether the kernel has AoE support. This can be found by grepping the kernel's config file for the CONFIG_ATA_OVER_ETH option as follows:

# grep ATA_OVER_ETH /boot/config-`uname -r`

This should produce the following result if support has been added as a module, otherwise a kernel recompile may be required (menuconfig options are under Device Drivers->Block Devices->ATA over Ethernet support):

CONFIG_ATA_OVER_ETH=m

Assuming a kernel with modular AoE support, the aoe module can be loaded with modprobe:

# modprobe aoe

Syslog should confirm that AoE is now available:

# tail /var/log/syslog

Nov 07 11:54:07 host kernel: aoe: aoe_init: AoE v22 initialised.

Next, install the vblade package using yum (if EPEL or local repo is setup) or rpm:

# yum install vblade

  or

# rpm -ivh vblade-14-3.el5.x86_64.rpm

Now export a partition as an AoE device. AoE devices are identified by Major/Minor numbers, with a Major number between 0-65535 and a Minor number between 0-255. Because AoE uses Ethernet directly without the TCP/IP layer, it is also necessary to specify the ethernet card. For example, to export the /dev/sda2 partition on eth0 with Major number 0 and Minor number 1, run the following command:

# vbladed 0 1 eth0 /dev/sda2

2: AoE initiator

AoE initiator utilities are provided by the aoetools package. Like AoE targets, AoE initiators also require a kernel which supports AoE.

# yum install aoetools

The aoe-discover command is used to discover AoE resources available on the network:

# aoe-discover

# aoe-stat

e0.1         5.000GB   eth0 up

There should now be new block device available named /dev/etherd/e0.1. A new node should be visible in the /dev filesystem:

# ls -al /dev/etherd/

total 4
drwxr-xr-x  2 root root     140 2007-10-10 13:30 .
drwxr-xr-x 16 root root   14660 2007-10-10 13:30 ..
c-w--w----  1 root disk 152,  3 2007-10-10 13:30 discover
brw-rw----  1 root disk 152, 16 2007-10-10 13:30 e0.1
cr--r-----  1 root disk 152,  2 2007-10-10 13:30 err
c-w--w----  1 root disk 152,  4 2007-10-10 13:30 interfaces
-rw-r--r--  1 root root       5 2007-10-10 13:00 revalidate

The AoE device can now be formatted and used like a locally attached block device:

# mkfs.ext3 /dev/etherd/e0.1