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+ATA over Ethernet is a network protocol that provides simple access to
+block storage on the LAN.
+ http://support.coraid.com/documents/AoEr11.txt
+The EtherDrive (R) HOWTO for 2.6 and 3.x kernels is found at ...
+ http://support.coraid.com/support/linux/EtherDrive-2.6-HOWTO.html
+It has many tips and hints! Please see, especially, recommended
+tunings for virtual memory:
+ http://support.coraid.com/support/linux/EtherDrive-2.6-HOWTO-5.html#ss5.19
+The aoetools are userland programs that are designed to work with this
+driver. The aoetools are on sourceforge.
+ http://aoetools.sourceforge.net/
+The scripts in this Documentation/aoe directory are intended to
+document the use of the driver and are not necessary if you install
+the aoetools.
+ Users of udev should find the block device nodes created
+ automatically, but to create all the necessary device nodes, use the
+ udev configuration rules provided in udev.txt (in this directory).
+ There is a udev-install.sh script that shows how to install these
+ rules on your system.
+ There is also an autoload script that shows how to edit
+ /etc/modprobe.d/aoe.conf to ensure that the aoe module is loaded when
+ necessary. Preloading the aoe module is preferable to autoloading,
+ however, because AoE discovery takes a few seconds. It can be
+ confusing when an AoE device is not present the first time the a
+ command is run but appears a second later.
+ "cat /dev/etherd/err" blocks, waiting for error diagnostic output,
+ like any retransmitted packets.
+ "echo eth2 eth4 > /dev/etherd/interfaces" tells the aoe driver to
+ limit ATA over Ethernet traffic to eth2 and eth4. AoE traffic from
+ untrusted networks should be ignored as a matter of security. See
+ also the aoe_iflist driver option described below.
+ "echo > /dev/etherd/discover" tells the driver to find out what AoE
+ devices are available.
+ In the future these character devices may disappear and be replaced
+ by sysfs counterparts. Using the commands in aoetools insulates
+ users from these implementation details.
+ The block devices are named like this:
+ e{shelf}.{slot}
+ e{shelf}.{slot}p{part}
+ ... so that "e0.2" is the third blade from the left (slot 2) in the
+ first shelf (shelf address zero). That's the whole disk. The first
+ partition on that disk would be "e0.2p1".
+ Each aoe block device in /sys/block has the extra attributes of
+ state, mac, and netif. The state attribute is "up" when the device
+ is ready for I/O and "down" if detected but unusable. The
+ "down,closewait" state shows that the device is still open and
+ cannot come up again until it has been closed.
+ The mac attribute is the ethernet address of the remote AoE device.
+ The netif attribute is the network interface on the localhost
+ through which we are communicating with the remote AoE device.
+ There is a script in this directory that formats this information in
+ a convenient way. Users with aoetools should use the aoe-stat
+ command.
+ root@makki root# sh Documentation/aoe/status.sh
+ e10.0 eth3 up
+ e10.1 eth3 up
+ e10.2 eth3 up
+ e10.3 eth3 up
+ e10.4 eth3 up
+ e10.5 eth3 up
+ e10.6 eth3 up
+ e10.7 eth3 up
+ e10.8 eth3 up
+ e10.9 eth3 up
+ e4.0 eth1 up
+ e4.1 eth1 up
+ e4.2 eth1 up
+ e4.3 eth1 up
+ e4.4 eth1 up
+ e4.5 eth1 up
+ e4.6 eth1 up
+ e4.7 eth1 up
+ e4.8 eth1 up
+ e4.9 eth1 up
+ Use /sys/module/aoe/parameters/aoe_iflist (or better, the driver
+ option discussed below) instead of /dev/etherd/interfaces to limit
+ AoE traffic to the network interfaces in the given
+ whitespace-separated list. Unlike the old character device, the
+ sysfs entry can be read from as well as written to.
+ It's helpful to trigger discovery after setting the list of allowed
+ interfaces. The aoetools package provides an aoe-discover script
+ for this purpose. You can also directly use the
+ /dev/etherd/discover special file described above.
+ There is a boot option for the built-in aoe driver and a
+ corresponding module parameter, aoe_iflist. Without this option,
+ all network interfaces may be used for ATA over Ethernet. Here is a
+ usage example for the module parameter.
+ modprobe aoe_iflist="eth1 eth3"
+ The aoe_deadsecs module parameter determines the maximum number of
+ seconds that the driver will wait for an AoE device to provide a
+ response to an AoE command. After aoe_deadsecs seconds have
+ elapsed, the AoE device will be marked as "down". A value of zero
+ is supported for testing purposes and makes the aoe driver keep
+ trying AoE commands forever.
+ The aoe_maxout module parameter has a default of 128. This is the
+ maximum number of unresponded packets that will be sent to an AoE
+ target at one time.
+ The aoe_dyndevs module parameter defaults to 1, meaning that the
+ driver will assign a block device minor number to a discovered AoE
+ target based on the order of its discovery. With dynamic minor
+ device numbers in use, a greater range of AoE shelf and slot
+ addresses can be supported. Users with udev will never have to
+ think about minor numbers. Using aoe_dyndevs=0 allows device nodes
+ to be pre-created using a static minor-number scheme with the
+ aoe-mkshelf script in the aoetools.