--- /dev/null
+Introduction
+============
+
+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.
+
+
+Creating Device Nodes
+=====================
+
+ 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.
+
+Using Device Nodes
+==================
+
+ "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".
+
+Using sysfs
+===========
+
+ 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.
+
+Driver Options
+==============
+
+ 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.
+++ /dev/null
-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.
-
-
-CREATING DEVICE NODES
-
- 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.
-
-USING DEVICE NODES
-
- "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".
-
-USING SYSFS
-
- 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.
-
-DRIVER OPTIONS
-
- 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.
--- /dev/null
+Example of udev rules
+---------------------
+
+ .. include:: udev.txt
+ :literal:
+
+Example of udev install rules script
+------------------------------------
+
+ .. literalinclude:: udev-install.sh
+ :language: shell
+
+Example script to get status
+----------------------------
+
+ .. literalinclude:: status.sh
+ :language: shell
+
+Example of AoE autoload script
+------------------------------
+
+ .. literalinclude:: autoload.sh
+ :language: shell
--- /dev/null
+:orphan:
+
+=======================
+ATA over Ethernet (AoE)
+=======================
+
+.. toctree::
+ :maxdepth: 1
+
+ aoe
+ todo
+ examples
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
--- /dev/null
+TODO
+====
+
+There is a potential for deadlock when allocating a struct sk_buff for
+data that needs to be written out to aoe storage. If the data is
+being written from a dirty page in order to free that page, and if
+there are no other pages available, then deadlock may occur when a
+free page is needed for the sk_buff allocation. This situation has
+not been observed, but it would be nice to eliminate any potential for
+deadlock under memory pressure.
+
+Because ATA over Ethernet is not fragmented by the kernel's IP code,
+the destructor member of the struct sk_buff is available to the aoe
+driver. By using a mempool for allocating all but the first few
+sk_buffs, and by registering a destructor, we should be able to
+efficiently allocate sk_buffs without introducing any potential for
+deadlock.
+++ /dev/null
-There is a potential for deadlock when allocating a struct sk_buff for
-data that needs to be written out to aoe storage. If the data is
-being written from a dirty page in order to free that page, and if
-there are no other pages available, then deadlock may occur when a
-free page is needed for the sk_buff allocation. This situation has
-not been observed, but it would be nice to eliminate any potential for
-deadlock under memory pressure.
-
-Because ATA over Ethernet is not fragmented by the kernel's IP code,
-the destructor member of the struct sk_buff is available to the aoe
-driver. By using a mempool for allocating all but the first few
-sk_buffs, and by registering a destructor, we should be able to
-efficiently allocate sk_buffs without introducing any potential for
-deadlock.
# udev_rules="/etc/udev/rules.d/"
# bash# ls /etc/udev/rules.d/
# 10-wacom.rules 50-udev.rules
-# bash# cp /path/to/linux-2.6.xx/Documentation/aoe/udev.txt \
+# bash# cp /path/to/linux/Documentation/aoe/udev.txt \
# /etc/udev/rules.d/60-aoe.rules
#
projects / mirror_ubuntu-focal-kernel.git / commitdiff