Difference between revisions of "Vblade - ATA over Ethernet"
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* AOE avoids the usual high-level TCP/IP or UDP protocols; it's a base-level protocol itself. (For the technically-minded, it is an OSI level 2 protocol.) This gives the advantage of higher speed transfers, as the protocol doesn't have to build upon existing structures. In comparison, iSCSI runs over TCP/IP.<ref>[http://gentoo-wiki.com/HOWTO_aoe Gentoo Linux Wiki:HOWTO aoe]</ref><ref>[http://linuxdevices.com/news/NS3189760067.html LinuxDevices.com - ATA-over-Ethernet enables low-cost Linux-oriented SAN]</ref><ref>[http://www.linuxjournal.com/article/8149 Linux Journal - Kernel Korner - ATA Over Ethernet: Putting Hard Drives on the LAN]</ref> | * AOE avoids the usual high-level TCP/IP or UDP protocols; it's a base-level protocol itself. (For the technically-minded, it is an OSI level 2 protocol.) This gives the advantage of higher speed transfers, as the protocol doesn't have to build upon existing structures. In comparison, iSCSI runs over TCP/IP.<ref>[http://gentoo-wiki.com/HOWTO_aoe Gentoo Linux Wiki:HOWTO aoe]</ref><ref>[http://linuxdevices.com/news/NS3189760067.html LinuxDevices.com - ATA-over-Ethernet enables low-cost Linux-oriented SAN]</ref><ref>[http://www.linuxjournal.com/article/8149 Linux Journal - Kernel Korner - ATA Over Ethernet: Putting Hard Drives on the LAN]</ref> | ||
* It apparently uses less CPU time than the similar [[w:iSCSI|iSCSI]] protocol. For the technically minded, the AoE specification<ref>[http://www.coraid.com/documents/AoEr8.txt Advanced Technology Attachment(ATA) over Ethernet - (AoE) ]</ref> <ref>[http://www.coraid.com/technology.html Coraid: The AoE Protocol]</ref> is 8 pages compared with iSCSI's<ref>[http://www.ietf.org/rfc/rfc3720.txt RFC 3720 - Internet Small Computer Systems Interface - (iSCSI)]</ref> 257 pages. | * It apparently uses less CPU time than the similar [[w:iSCSI|iSCSI]] protocol. For the technically minded, the AoE specification<ref>[http://www.coraid.com/documents/AoEr8.txt Advanced Technology Attachment(ATA) over Ethernet - (AoE) ]</ref> <ref>[http://www.coraid.com/technology.html Coraid: The AoE Protocol]</ref> is 8 pages compared with iSCSI's<ref>[http://www.ietf.org/rfc/rfc3720.txt RFC 3720 - Internet Small Computer Systems Interface - (iSCSI)]</ref> 257 pages. | ||
− | * AoE is not routable over [[w:local area network|LAN]]s and is intended for SANs only, which can provide | + | * AoE is not routable over [[w:local area network|LAN]]s and is intended for SANs only, which can provide greatly increased security. |
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==Disadvantages== | ==Disadvantages== | ||
* Each partition on the server computer can only be used by one client at a time; AOE is not intended to be a replacement for NFS or similar protocols which run on top of filesystems. It is designed to work at a much lower level. | * Each partition on the server computer can only be used by one client at a time; AOE is not intended to be a replacement for NFS or similar protocols which run on top of filesystems. It is designed to work at a much lower level. |
Revision as of 13:33, 28 August 2006
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Contents
Background
ATA over Ethernet (AoE)[1] is a network protocol developed by the Brantley Coile Company (now Coraid)[2], designed for accessing ATA storage devices over Ethernet networks. It gives the possibility to build SANs with low-cost, standard technologies. AoE does not rely on network layers above Ethernet, such as IP, UDP, TCP, etc.
Advantages
- AOE avoids the usual high-level TCP/IP or UDP protocols; it's a base-level protocol itself. (For the technically-minded, it is an OSI level 2 protocol.) This gives the advantage of higher speed transfers, as the protocol doesn't have to build upon existing structures. In comparison, iSCSI runs over TCP/IP.[3][4][5]
- It apparently uses less CPU time than the similar iSCSI protocol. For the technically minded, the AoE specification[6] [7] is 8 pages compared with iSCSI's[8] 257 pages.
- AoE is not routable over LANs and is intended for SANs only, which can provide greatly increased security.
Disadvantages
- Each partition on the server computer can only be used by one client at a time; AOE is not intended to be a replacement for NFS or similar protocols which run on top of filesystems. It is designed to work at a much lower level.
- As the protocol is non-routable, the servers cannot be separated by routers.
Uses
- ATA Over Ethernet is therefore useful for creating cheap SANs, but it is not intended for the average user. It is very definitely not useful for sharing files easily: NFS or Samba is much better for this.
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Installation
The Linkstation is used as a server running vblade. A separate computer is a client running aoetools. This version of vblade runs in userspace, however there are versions that run in kernelspace.[9][10]
USB Drive |
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I bricked my LS when trying to mount an internal partition the first time I tried this, so I used a usb drive this time around. Which on my LinkStation was /dev/sda1 - Ramuk |
Server (vblade)
FreeLink
Use aptitude to install the vblade componant of AoE[11]. You will need to have the unstable branch added.
- Get access to packages from the Debian unstable branch
- use apt-get to install vblade:
apt-get install vblade
usage: vblade <shelf> <slot> <ethn> <device>
vblade 1 2 eth0 /dev/sda1 &
Client (aoetools)
Install the aoetools[12] package [13] using aptitude. You will need to have Unstable (Debian) or Testing (Debian) branch enabled.
My Client |
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In this case I have a PIII/600 Compaq Armada laptop running Ubuntu Dapper Drake. - Ramuk |
sudo apt-get aoetools mkdir mountpoint sudo modprobe aoe
check to see that your vblade device is available to mount
sudo aoe-stat
you should see output like this:
e1.2 20.003GB eth0 up
Mount this device on your client
sudo mount -t vfat /dev/etherd/e1.2 mountpoint/
and try it out, hopefully it works. There is some useful Linux support on the Coraid site[14]
References
- ↑ Wikipedia:ATA over Ethernet
- ↑ Coraid:: The Linux Storage People
- ↑ Gentoo Linux Wiki:HOWTO aoe
- ↑ LinuxDevices.com - ATA-over-Ethernet enables low-cost Linux-oriented SAN
- ↑ Linux Journal - Kernel Korner - ATA Over Ethernet: Putting Hard Drives on the LAN
- ↑ Advanced Technology Attachment(ATA) over Ethernet - (AoE)
- ↑ Coraid: The AoE Protocol
- ↑ RFC 3720 - Internet Small Computer Systems Interface - (iSCSI)
- ↑ Vblade Linux kernel module
- ↑ Sourceforge: Kvblade
- ↑ Sourceforge: Vblade
- ↑ Sourceforge: ATA Over Ethernet Tools
- ↑ Debian Package: aoetools - tools to assist in using ATA over Ethernet
- ↑ Linux Support for EtherDrive (R) Storage