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This is pretty much just plain curiosity. But there is a thing called ATA-over-Ethernet, which should be supported by Linux and which allows you to export raw disk access over Ethernet directly in order to form a SAN. This is something I'll most likely never have to do, but it sounds cool, so I'd like to try it. I don't have the hardware for that kind of experiment, however, so I was wondering if it would be possible to create a bridge and a number of virtual machines, each exporting a number of virtual disks as ATA devices and then use those on another physical machine in the network?

Jo-Erlend Schinstad
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As davidgo pointed out, there are some things to consider first about ATA over Ethernet: It's old and suboptimal to a solved problem (iSCSI) and may not be a good solution. ATA over ethernet is a very niche market - it does not use tcp - so it can't span routers and is difficult to secure if not directly attached (so whats the point over plugging it in directly?) , its not as scalable and not as well supported in places where its most useful (eg VMs). That said, it might be more performant in certain limited scenarios because its slightly lower overhead.

A better method might be to use iSCSI instead (Wikipedia or searchstorage.techtarget.com), debian has some promising packages like open-iscsi or perhaps Cinder.

But if you're still determined to try AoE and if there's programs for it, then sure why not? Searching debian's packages for ata over ethernet shows a lot of results (I'm not too sure if it's "exact search" is doing what you'd expect though), but some promising candidates are:

Package: vblade (23-1)

virtual AoE blade emulator

The vblade is the virtual EtherDrive (R) blade, a program that makes a seekable file available over an ethernet local area network (LAN) via the ATA over Ethernet (AoE) protocol.

The seekable file is typically a block device like /dev/md0 but even regular files will work. Sparse files can be especially convenient. When vblade exports the block storage over AoE it becomes a storage target. Another host on the same LAN can access the storage if it has a compatible aoe kernel driver

Package: aoetools (36-2)

tools to assist in using ATA over Ethernet

The aoetools are programs that assist in using ATA over Ethernet. These tools are designed to work with the "aoe" driver for Linux 2.6+ kernels; in fact, this version recommends kernel 2.6.14 or later, as both support up to 16 slots per shelf address.

Systems running Linux 2.4 kernels do not need and should not install the aoetools. The aoe driver for 2.4 kernels is self-sufficient.

There are several tools included in this package:

  • aoecfg - manipulate AoE configuration strings
  • aoe-discover - trigger discovery of ATA over Ethernet devices
  • aoe-flush - flush the down devices out of the aoe driver
  • aoe-interfaces - restrict network interfaces used for AoE
  • aoe-mkdevs - create character and block device files
  • aoe-mkshelf - create block device files for one shelf address
  • aoeping - simple userland communication with AoE devices
  • aoe-revalidate - revalidate the disk size of an AoE device
  • aoe-sancheck - diagnoses MTU and other network issues
  • aoe-stat - print status information for AoE devices
  • aoe-version - print AoE-related software version information
  • coraid-update - upload an update file to a Coraid appliance

Running even one and connecting to it from another computer (virtual or other) should be fine

Xen2050
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