aoe – ATA–over–Ethernet (AoE) interface|
bind –a #æ /dev |
The AoE (ATA–over–Ethernet) interface serves a three–level directory
providing control and access to AoE targets. The interface provided
is primarily intended for low–level control of the AoE initiator.
See sdaoe(3) for the standard interface.|
Each local interface is called a netlink. The mapping of AoE targets to netlinks is called a devlink. Each devlink may see multiple interfaces per target. For example, if the local machine has one Ethernet address bound and the target has two interfaces on the same Ethernet segment, this will result in one netlink and one devlink with two Ethernet addresses. AoE frames are sent in round–robin fashion. Each successive frame is sent on the next address available on the next available devlink (local interface).
Normally the initiator automatically discovers and adds new device
directories on startup. New devices are not added except as new
interfaces are bound to the initiator. Several messages can be
written to /dev/aoe/ctl which alter this behavior:
rediscover Returns the current state of the variable named by the keyword. Writing the variable's name to the control file toggles the state of that variable.
ifn path Path to nth bound Ethernet device.
ifn ea Ethernet address of this device.
ifn flag A flag of ``Up'' indicates that this interface is available.
ifn lostjumbo Number of consecutive lost jumbograms.
ifn datamtu Incorrect and unused.
Reading a target's ctl file returns a list of colon–separated lines
with the following keywords and values:
Writing to the ctl file, the following commands may be issued:
The data file may be read or written like a normal file except that reads and writes to this file are converted to AoE commands to the target, so transfers should be 512 or 1024 bytes long (or a larger multiple of 512 iff jumbo packets are in use). The size of this file is the usable size of the target.
The devlink directory contains one file for each interface the
target was discovered on. The files are numbers from 0 to n and
contain a list of colon–separated lines with keywords and their
sd(3), sdaoe(3), aoesrv(8), snoopy(8)|
Van Jacobson and Michael J. Karels, ``Congestion Avoidance and Control'', ACM Computer Communication Review; Proceedings of the Sigcomm '88 Symposium in Stanford, CA, August, 1988.
There is no raw file for executing arbitrary commands. |
This is a fairly primitive interface; sdaoe(3) is usually more