Based on kernel version 4.16.1. Page generated on 2018-04-09 11:52 EST.
1 ATA over Ethernet is a network protocol that provides simple access to 2 block storage on the LAN. 3 4 http://support.coraid.com/documents/AoEr11.txt 5 6 The EtherDrive (R) HOWTO for 2.6 and 3.x kernels is found at ... 7 8 http://support.coraid.com/support/linux/EtherDrive-2.6-HOWTO.html 9 10 It has many tips and hints! Please see, especially, recommended 11 tunings for virtual memory: 12 13 http://support.coraid.com/support/linux/EtherDrive-2.6-HOWTO-5.html#ss5.19 14 15 The aoetools are userland programs that are designed to work with this 16 driver. The aoetools are on sourceforge. 17 18 http://aoetools.sourceforge.net/ 19 20 The scripts in this Documentation/aoe directory are intended to 21 document the use of the driver and are not necessary if you install 22 the aoetools. 23 24 25 CREATING DEVICE NODES 26 27 Users of udev should find the block device nodes created 28 automatically, but to create all the necessary device nodes, use the 29 udev configuration rules provided in udev.txt (in this directory). 30 31 There is a udev-install.sh script that shows how to install these 32 rules on your system. 33 34 There is also an autoload script that shows how to edit 35 /etc/modprobe.d/aoe.conf to ensure that the aoe module is loaded when 36 necessary. Preloading the aoe module is preferable to autoloading, 37 however, because AoE discovery takes a few seconds. It can be 38 confusing when an AoE device is not present the first time the a 39 command is run but appears a second later. 40 41 USING DEVICE NODES 42 43 "cat /dev/etherd/err" blocks, waiting for error diagnostic output, 44 like any retransmitted packets. 45 46 "echo eth2 eth4 > /dev/etherd/interfaces" tells the aoe driver to 47 limit ATA over Ethernet traffic to eth2 and eth4. AoE traffic from 48 untrusted networks should be ignored as a matter of security. See 49 also the aoe_iflist driver option described below. 50 51 "echo > /dev/etherd/discover" tells the driver to find out what AoE 52 devices are available. 53 54 In the future these character devices may disappear and be replaced 55 by sysfs counterparts. Using the commands in aoetools insulates 56 users from these implementation details. 57 58 The block devices are named like this: 59 60 e{shelf}.{slot} 61 e{shelf}.{slot}p{part} 62 63 ... so that "e0.2" is the third blade from the left (slot 2) in the 64 first shelf (shelf address zero). That's the whole disk. The first 65 partition on that disk would be "e0.2p1". 66 67 USING SYSFS 68 69 Each aoe block device in /sys/block has the extra attributes of 70 state, mac, and netif. The state attribute is "up" when the device 71 is ready for I/O and "down" if detected but unusable. The 72 "down,closewait" state shows that the device is still open and 73 cannot come up again until it has been closed. 74 75 The mac attribute is the ethernet address of the remote AoE device. 76 The netif attribute is the network interface on the localhost 77 through which we are communicating with the remote AoE device. 78 79 There is a script in this directory that formats this information in 80 a convenient way. Users with aoetools should use the aoe-stat 81 command. 82 83 root@makki root# sh Documentation/aoe/status.sh 84 e10.0 eth3 up 85 e10.1 eth3 up 86 e10.2 eth3 up 87 e10.3 eth3 up 88 e10.4 eth3 up 89 e10.5 eth3 up 90 e10.6 eth3 up 91 e10.7 eth3 up 92 e10.8 eth3 up 93 e10.9 eth3 up 94 e4.0 eth1 up 95 e4.1 eth1 up 96 e4.2 eth1 up 97 e4.3 eth1 up 98 e4.4 eth1 up 99 e4.5 eth1 up 100 e4.6 eth1 up 101 e4.7 eth1 up 102 e4.8 eth1 up 103 e4.9 eth1 up 104 105 Use /sys/module/aoe/parameters/aoe_iflist (or better, the driver 106 option discussed below) instead of /dev/etherd/interfaces to limit 107 AoE traffic to the network interfaces in the given 108 whitespace-separated list. Unlike the old character device, the 109 sysfs entry can be read from as well as written to. 110 111 It's helpful to trigger discovery after setting the list of allowed 112 interfaces. The aoetools package provides an aoe-discover script 113 for this purpose. You can also directly use the 114 /dev/etherd/discover special file described above. 115 116 DRIVER OPTIONS 117 118 There is a boot option for the built-in aoe driver and a 119 corresponding module parameter, aoe_iflist. Without this option, 120 all network interfaces may be used for ATA over Ethernet. Here is a 121 usage example for the module parameter. 122 123 modprobe aoe_iflist="eth1 eth3" 124 125 The aoe_deadsecs module parameter determines the maximum number of 126 seconds that the driver will wait for an AoE device to provide a 127 response to an AoE command. After aoe_deadsecs seconds have 128 elapsed, the AoE device will be marked as "down". A value of zero 129 is supported for testing purposes and makes the aoe driver keep 130 trying AoE commands forever. 131 132 The aoe_maxout module parameter has a default of 128. This is the 133 maximum number of unresponded packets that will be sent to an AoE 134 target at one time. 135 136 The aoe_dyndevs module parameter defaults to 1, meaning that the 137 driver will assign a block device minor number to a discovered AoE 138 target based on the order of its discovery. With dynamic minor 139 device numbers in use, a greater range of AoE shelf and slot 140 addresses can be supported. Users with udev will never have to 141 think about minor numbers. Using aoe_dyndevs=0 allows device nodes 142 to be pre-created using a static minor-number scheme with the 143 aoe-mkshelf script in the aoetools.