ATA over Ethernet and Grml

Update on 2011-12-20 by Grml team: while iscsitarget isn’t available any longer on Grml the new iSCSI implementation of the Linux kernel 3.1 is available and open-iscsi, targetcli and tgt are shipped with Grml. We don’t have any finished documentation for that yet, but if you know how to use targetcli (or optionally open-iscsi and tgt) you should have everything you need to provide a iscsi target with Grml 2011.12.

The upcoming Grml Release 2011.12 (check the changelog for our new Grml 2011.12-rc1) will not have any iSCSI support integrated due to build issues with dkms. Instead Grml 2011.12 will provide all the necessary tools to provide and access a ATA over Ethernet Device.

ATA over Ethernet, also known as AoE, is a protocol designed to access Block devices via Ethernet. Compared to iSCSI it does not work with IP but with Ethernet. Unfortunately this means that AoE is error-prone against Ethernet attacks like ARP spoofing. Do not use it in hostile enviornments. That being said AoE is quite simple to use.

Export a blockdevice

On the server side use vblade to export a block device:

vblade -m 11:22:33:44:55:66 160 2 eth0 /dev/sdb1

This will allow the host with the MAC 11:22:33:44:55:66 to access /dev/sdb1 via eth0, using the shelf and slot numbers 160 and 2. These numbers are arbitrary but should be unique within the network.

Access a blockdevice

On the client load the module “aoe”, or do

aoe-discover

You should find the device shared above as /dev/etherd/e160.2

I would like to thank to Christoph Biedl for providing this short and comprehensive documentation