291 lines
6.5 KiB
Plaintext
291 lines
6.5 KiB
Plaintext
|
.TH AOE 3
|
||
|
|
.SH NAME
|
||
|
|
aoe \- ATA-over-Ethernet (AoE) interface
|
||
|
|
.SH SYNOPSIS
|
||
|
|
.nf
|
||
|
|
.B bind -a #æ /dev
|
||
|
|
.sp 0.3v
|
||
|
|
.B /dev/aoe/ctl
|
||
|
|
.B /dev/aoe/log
|
||
|
|
.BI /dev/aoe/ shelf . slot /config
|
||
|
|
.BI /dev/aoe/ shelf . slot /ctl
|
||
|
|
.BI /dev/aoe/ shelf . slot /devlink/0
|
||
|
|
\&...
|
||
|
|
.BI /dev/aoe/ shelf . slot /devlink/ i
|
||
|
|
.BI /dev/aoe/ shelf . slot /ident
|
||
|
|
\&...
|
||
|
|
.fi
|
||
|
|
.SH DESCRIPTION
|
||
|
|
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
|
||
|
|
.IR sdaoe (3)
|
||
|
|
for the standard interface.
|
||
|
|
.SS Top-level files
|
||
|
|
In order to access AoE targets, one or more Ethernet controllers
|
||
|
|
need to be bound to the AoE initiator. By default, the system
|
||
|
|
starts with no interfaces bound. For automatic binding of interfaces
|
||
|
|
on boot, the
|
||
|
|
.B aoeif
|
||
|
|
configuration variable is set in
|
||
|
|
.IR plan9.ini (8).
|
||
|
|
Ethernet interfaces are specified as
|
||
|
|
.BI ether n\fR,
|
||
|
|
not as
|
||
|
|
.BI #l n\fR.
|
||
|
|
To bind the first and second Ethernet devices on boot, add
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
aoeif=ether0 ether1
|
||
|
|
.EE
|
||
|
|
.PP
|
||
|
|
To bind
|
||
|
|
.B ether1
|
||
|
|
to a running system:
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
% echo bind '#l1/ether1' >/dev/aoe/ctl
|
||
|
|
.EE
|
||
|
|
.PP
|
||
|
|
And to unbind it
|
||
|
|
.IP
|
||
|
|
.EX
|
||
|
|
% echo unbind '#l1/ether1' >/dev/aoe/ctl
|
||
|
|
.EE
|
||
|
|
.PP
|
||
|
|
When an interface is unbound, targets depending
|
||
|
|
on that interface are removed.
|
||
|
|
.PP
|
||
|
|
Each local interface is called a
|
||
|
|
.IR netlink .
|
||
|
|
The mapping of
|
||
|
|
AoE targets to netlinks is called a
|
||
|
|
.IR 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).
|
||
|
|
.PP
|
||
|
|
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
|
||
|
|
.B /dev/aoe/ctl
|
||
|
|
which alter this behavior:
|
||
|
|
.TP
|
||
|
|
.BI autodiscover\ toggle
|
||
|
|
If toggle is absent,
|
||
|
|
the state of
|
||
|
|
.B autodiscover
|
||
|
|
is toggled. If it is the string
|
||
|
|
.BR on ,
|
||
|
|
it is turned on. Any other string turns
|
||
|
|
.B autodisover
|
||
|
|
off.
|
||
|
|
This option is not useful after Ethernet devices have been bound.
|
||
|
|
.TP
|
||
|
|
.BI discover\ shelf.slot
|
||
|
|
Attempt to find the named target on all bound interfaces.
|
||
|
|
.TP
|
||
|
|
.BI remove\ shelf.slot
|
||
|
|
The converse of
|
||
|
|
.BR discover :
|
||
|
|
remove the named target if it exists.
|
||
|
|
.TP
|
||
|
|
.BI rediscover\ toggle
|
||
|
|
Allow or disallow rediscovery.
|
||
|
|
This allows for automatic discovery of new targets.
|
||
|
|
Unfortunately, it also allows automatic modification
|
||
|
|
or loss of existing targets. This option is considered dangerous.
|
||
|
|
.br
|
||
|
|
.ne 4
|
||
|
|
.PP
|
||
|
|
Reading
|
||
|
|
.B /dev/aoe/ctl
|
||
|
|
returns a list of colon-separated lines
|
||
|
|
with keywords and their values:
|
||
|
|
.TF rediscover
|
||
|
|
.PD
|
||
|
|
.TP
|
||
|
|
.BI debug
|
||
|
|
.PD 0
|
||
|
|
.TP
|
||
|
|
.BI autodiscover
|
||
|
|
.TP
|
||
|
|
.B 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.
|
||
|
|
.PD
|
||
|
|
.TP
|
||
|
|
.BI if "n path"
|
||
|
|
Path to
|
||
|
|
.IR n th
|
||
|
|
bound Ethernet device.
|
||
|
|
.TP
|
||
|
|
.BI if "n ea"
|
||
|
|
Ethernet address of this device.
|
||
|
|
.TP
|
||
|
|
.BI if "n flag"
|
||
|
|
A flag of ``Up'' indicates that this interface is available.
|
||
|
|
.TP
|
||
|
|
.BI if "n lostjumbo"
|
||
|
|
Number of consecutive lost jumbograms.
|
||
|
|
.TP
|
||
|
|
.BI if "n datamtu"
|
||
|
|
Incorrect and unused.
|
||
|
|
.SS Shelf-and-slot subdirectories
|
||
|
|
Once configured, each AoE target is accessed via files in the directory named
|
||
|
|
for its shelf and slot. For example, shelf 42, slot 0 would be
|
||
|
|
accessed through the path
|
||
|
|
.LR /dev/aoe/42.0 .
|
||
|
|
The
|
||
|
|
.B ident
|
||
|
|
file contains the read-only, verbatim result of the identify unit ATA command.
|
||
|
|
The
|
||
|
|
.B config
|
||
|
|
file contains the target's AoE configuration string. Writing to this file
|
||
|
|
sets the targets configuration string.
|
||
|
|
.PP
|
||
|
|
Reading a shelf and slot's
|
||
|
|
.B ctl
|
||
|
|
file returns a list of colon-separated lines
|
||
|
|
with the following keywords and values:
|
||
|
|
.TF firmware
|
||
|
|
.PD
|
||
|
|
.TP
|
||
|
|
.B state
|
||
|
|
``Up'' or ``down''.
|
||
|
|
.TP
|
||
|
|
.B nopen
|
||
|
|
Number of clients using this target.
|
||
|
|
.TP
|
||
|
|
.B nout
|
||
|
|
Number of outstanding AoE frames.
|
||
|
|
.TP
|
||
|
|
.B nmaxout
|
||
|
|
Maximum number of outstanding frames allowed.
|
||
|
|
.TP
|
||
|
|
.B nframes
|
||
|
|
Maximum number of outstanding frames.
|
||
|
|
.I Nframes
|
||
|
|
is greater than
|
||
|
|
.I nmaxout
|
||
|
|
when the initiator is reducing the number of in-flight
|
||
|
|
frames due to packet loss. It is assumed that packet
|
||
|
|
loss is due to an overwhelmed target and not poor
|
||
|
|
network conditions.
|
||
|
|
.TP
|
||
|
|
.BI maxbcount
|
||
|
|
Maximum number of data bytes per AoE frame. Using
|
||
|
|
standard frames,
|
||
|
|
.B maxbcount
|
||
|
|
is 1024 or two sectors.
|
||
|
|
AoE ATA headers are 36 bytes.
|
||
|
|
.TP
|
||
|
|
.B model
|
||
|
|
.PD 0
|
||
|
|
.TP
|
||
|
|
.B serial
|
||
|
|
.TP
|
||
|
|
.B firmware
|
||
|
|
The respective fields from the ATA
|
||
|
|
.B identify unit
|
||
|
|
command.
|
||
|
|
.PD
|
||
|
|
.TP
|
||
|
|
.B flag
|
||
|
|
List of flags useful for debugging. The flag
|
||
|
|
.B jumbo
|
||
|
|
indicates that jumbo frames are accepted, not that
|
||
|
|
they are being used.
|
||
|
|
.I Maxbcount
|
||
|
|
should be consulted for this purpose.
|
||
|
|
.PP
|
||
|
|
The
|
||
|
|
.B 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.
|
||
|
|
.PP
|
||
|
|
The
|
||
|
|
.B devlink
|
||
|
|
directory contains one file for each interface the target was
|
||
|
|
discovered on. The files are numbers from 0 to
|
||
|
|
.I n
|
||
|
|
and contain a list of colon-separated lines
|
||
|
|
with keywords and their values:
|
||
|
|
.TF mintimer
|
||
|
|
.PD
|
||
|
|
.TP
|
||
|
|
.B addr
|
||
|
|
A space-separated list of the target's Ethernet addresses visible from
|
||
|
|
this interface.
|
||
|
|
.TP
|
||
|
|
.B npkt
|
||
|
|
The number of frames sent on this interface.
|
||
|
|
.TP
|
||
|
|
.B resent
|
||
|
|
The number of frames re-sent. Frames are re-sent
|
||
|
|
when they have been outstanding twice the RTT average.
|
||
|
|
.TP
|
||
|
|
.B flag
|
||
|
|
``Up'' when the netlink is up.
|
||
|
|
.TP
|
||
|
|
.B rttavg
|
||
|
|
.PD 0
|
||
|
|
.TP
|
||
|
|
.B mintimer
|
||
|
|
Minimum timer and RTT average as per
|
||
|
|
.IR "Congestion Avoidance and Control" .
|
||
|
|
.PD
|
||
|
|
.TP
|
||
|
|
.B nl path
|
||
|
|
Path of the Ethernet device.
|
||
|
|
.TP
|
||
|
|
.B nl ea
|
||
|
|
Ethernet address of the local Ethernet device.
|
||
|
|
.TP
|
||
|
|
.B nl flag
|
||
|
|
``Up'' if the local interface is up.
|
||
|
|
.TP
|
||
|
|
.B nl lostjumbo
|
||
|
|
Number of consecutive jumbograms lost.
|
||
|
|
.TP
|
||
|
|
.B nl datamtu
|
||
|
|
Unused.
|
||
|
|
.PP
|
||
|
|
.SH SOURCE
|
||
|
|
.B /sys/src/9/port/devaoe.c
|
||
|
|
.SH SEE ALSO
|
||
|
|
.\" .IR cec (1),
|
||
|
|
.\" .IR vblade (1),
|
||
|
|
.IR sd (3),
|
||
|
|
.IR sdaoe (3),
|
||
|
|
.IR aoesrv (8),
|
||
|
|
.IR snoopy (8)
|
||
|
|
.br
|
||
|
|
.BR http://www.coraid.com/documents/AoEr10.txt
|
||
|
|
.br
|
||
|
|
Van Jacobson and Michael J. Karels,
|
||
|
|
.IR "``Congestion Avoidance and Control''" ,
|
||
|
|
ACM Computer Communication Review;
|
||
|
|
Proceedings of the Sigcomm '88 Symposium in Stanford, CA, August, 1988.
|
||
|
|
.SH BUGS
|
||
|
|
There is no
|
||
|
|
.B raw
|
||
|
|
file for executing arbitrary commands.
|
||
|
|
.PP
|
||
|
|
This is a fairly primitive interface;
|
||
|
|
.IR sdaoe (3)
|
||
|
|
is usually more suitable.
|