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"POT-Creation-Date: 2010-10-21 23:56+0600\n"
"PO-Revision-Date: 2010-10-21 23:46+0600\n"
"Last-Translator: Automatically generated\n"
"Language-Team: none\n"
"Language: ru\n"
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#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(title):6
msgid "Multipathing for Gentoo"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(author:title):8
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(author:title):11
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(author:title):14
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(author:title):17
msgid "Author"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(mail:link):9
msgid "tsunam"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(mail:link):12
msgid "matthew.summers@liquidustech.com"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(mail):12
msgid "Matthew Summers"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(mail:link):15
msgid "richard.anderson@liquidustech.com"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(mail):15
msgid "Richard Anderson"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(mail:link):18
msgid "steve.rucker@liquidustech.com"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(mail):18
msgid "Steve Rucker"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(author:title):20
msgid "Editor"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(mail:link):21
msgid "nightmorph"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(abstract):24
msgid ""
"This document teaches you how to set up multipathing services for data "
"storage."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(version):32
msgid "1"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(date):33
msgid "2008-09-10"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(title):36
msgid "Introduction"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):40
msgid ""
"Multipathing services, generally deployed in enterprise environments, "
"provide a means for high performance, load-balanced, and fault-tolerant data "
"storage either locally or via a storage area network (SAN). Multipathing "
"facilitates a single storage device to be transparently accessed across one "
"or more paths. For example, if there are two connections from a server Host "
"Bus Adapter (HBA) to two Fibre Channel switches and then to a SAN, when the "
"HBA module loads and scans the bus, it will read four paths to the SAN: the "
"paths from the server HBA to and from each Fibre Channel switch and at the "
"storage device. Taking advantage of this situation, Multipath allows you to "
"make use of each path simultaneously or independently to ensure a constant "
"and reliable connection to the data in storage. Multipath serves as a "
"failover for all connections points in the event of losing one path making "
"critical data always available due to redundancy in the design and "
"implementation."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):56
msgid ""
"In the most basic sense, multipathing is made of two distinct parts: "
"device-mapper and multipath-tools. Device Mapper is the "
"first key element of this application. Administrators are probably familiar "
"with Device Mapper from LVM, EVMS, dm-crypt, or in this case, Multipath. In "
"short, working within the kernel space Device Mapper takes one block device "
"such as /dev/sda (as all SAN based targets will be some type of "
"SCSI device) and maps it to another device."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):66
msgid ""
"On a lower level, Device Mapper creates a virtual block device accepting all "
"of the commands of a regular block device, but passes on the actual data to "
"the real block device. As previously stated, the mapping process is all "
"handled in the kernel space and not in user space."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):73
msgid ""
"Multipath Tools is a set of userspace tools that interacts with the "
"Device Mapper tools and creates structures for device handling, implementing "
"I/O multipathing at the OS level. In a typical SAN environment, you will "
"have multiple paths to the same storage device: a fiber card (or two) on "
"your server that connects to a switch which then connects to the actual "
"storage itself (as in the scenario discussed above). So administrators could "
"possibly see the same device one to four times in such a situation (each "
"card will see the LUN twice, once for each path it has available to it). "
"Thus, a single drive could be recognized as sda, sdb"
"path>, sdc, and sdd. If you were to mount /"
"dev/sda to /san1, for instance, you would be going over "
"the singular path from one fiber card to a switch and then to a port on the "
"same storage device. If any of those points were to fail, you would lose "
"your storage device suddenly and have to unmount and remount with another "
"device (sdb)."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):90
msgid ""
"Consequently, this scenario is not ideal as you are only using one out of "
"the four possible paths. This is where the combination of Multipath tools "
"and Device Mapper are beneficial. As already explained, Device Mapper "
"creates virtual block devices and then passes information to the real block "
"devices."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(title):102
msgid "Installation and Configuration"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(title):104
msgid "Installation and Tools"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):107
msgid ""
"You need to emerge multipath-tools and sg3_utils. On the disk, "
"you want to find the wwid. You can use sq_vpd (provided by "
"sg3_utils) to do this."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre:caption):113
msgid "Installing multipath-tools and initial configuration"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre):113
#, no-wrap
msgid ""
"\n"
"# emerge multipath-tools sg3_utils\n"
"(Replace /dev/DEVICE with your disk to find its wwid)\n"
"# /usr/bin/sq_vpd ?page=di /dev/DEVICE\n"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):119
msgid ""
"Where DEVICE is the sd device, the ID will come back with a 0x6. "
"Replace 0x with 3, and you will have the proper ID that you'll "
"put into the multipath wwid in /etc/multipath.conf. More "
"on this in the next chapter."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(title):129
msgid "Configuring Gentoo for multipathing"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):132
msgid ""
"To configure Gentoo for multipath, your kernel needs the following settings:"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre:caption):136
msgid "Adding multipath support"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre):136
#, no-wrap
msgid ""
"\n"
"Device Drivers --->\n"
" SCSI device support --->\n"
" <*> SCSI target support\n"
" <*> SCSI disk support\n"
" [*] Probe all LUNs on each SCSI device\n"
" [*] Multiple devices driver support (RAID and LVM) --->\n"
" <*> Multipath I/O support\n"
" <*> Device mapper support\n"
" <*> Multipath target\n"
" (Select your device from the list))\n"
" <*> EMC CX/AX multipath support \n"
" <*> LSI/Engenio RDAC multipath support \n"
" <*> HP MSA multipath support\n"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(note):152
msgid ""
"scsi_id is done by targets. IDE drives have two spots to which you "
"can connect. An administrator has the ability to set a drive as a master and "
"another drive as a slave or set to autoselect by changing the dip switches. "
"scsi_id is similar. Each drive or Logical Unit Number (LUN) has a unique ID, "
"which ranges from 0 to 254. A device that has ID 0 will be discovered before "
"a device that has, for example, ID 120, because it performs a LIP (a scan of "
"the SCSI bus for devices that respond) that starts from 0 and works its way "
"upwards."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):162
msgid ""
"In the kernel menu config, make sure CONFIG_SCSI_MULTI_LUN=y is set to "
"ensure the SCSI subsystem is able to probe all Logical Unit Numbers (LUNs) "
"(This is recommended as you'll stop scanning after ID 0 if you have a device "
"on an ID of 0 but not 1 and then on an ID of 2. Simply, "
"you'll get your device for ID 0 but not 2.) or whichever "
"device you need for SCSI, such as a QLogic 2400 card, which is in the SCSI "
"low-level drivers area."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):171
msgid "For a better understanding, consider the following scenarios:"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):175
msgid ""
"There are three drives with IDs of 0,1,2. Without the \"probe all LUNs\" "
"setting, you will see IDs 0,1,2 as sda,sdb,sdc - all devices are seen. If "
"you delete the ID 1 drive. IDs 0,2 will still be seen. It might seem to make "
"sense that you would see sda and sdb now (sdc would move to sdb as there is "
"no device to fill it up). However, if you don't probe all LUNs, it will "
"perform in the following manner:"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):184
msgid ""
"Scenario 1: Without \"probe all LUNs\", the scan will start and ID 0 will be "
"seen. ID 0 will be set to sda and then move to find ID 1. If ID 1 is not "
"detected, scanning will stop and be considered complete having perceived to "
"have scanned all devices even if there is a device on ID 2 or any other "
"subsequent ID. Reboot for scenario two."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):192
msgid ""
"Scenario 2: If you have \"probe all LUNs\", the scan will start and detect "
"ID 0. This ID will be assigned sda and will continue to detect the next "
"device. If ID 1 is not detected, scanning will continue to find more "
"devices. ID 2 will be located and assigned to be sdb. If no devices (IDs) "
"are detected beyond that, scanning will be considered complete."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(note):200
msgid ""
"Although it seems that it is unfeasible or even unnecessary to have devices "
"spaced many LUNs apart, to account for all options it is necessary to still "
"probe all LUNs. An administrator will encounter many reasons (business or "
"personal) for such a setup. Therefore, the second scenario would be optimal "
"to ensure that all devices are recognized and assigned an ID in the "
"multipath setup process."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):209
msgid ""
"So, once you probe all LUNs, all devices will be recognized and assigned an "
"ID in Multipath."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(title):219
msgid "Architectural Overview"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):223
msgid ""
"As part of Multipath Tools, there are priority groups filled with the "
"devices mentioned earlier. After you have configured multipath-tools "
"and started it with /etc/init.d/multipath start, you can list the "
"groups via multipath -l. The output will look like the following:"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre:caption):230
msgid "multipath -l output"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre):230
#, no-wrap
msgid ""
"\n"
"EVA_SAN (3600508b4001044ee00013000031e0000)\n"
"[size=300 GB][features=\"1 queue_if_no_path\"][hwhandler=\"0\"]\n"
"\\_ round-robin 0 [active]\n"
"\\_ 0:0:0:1 sda 8:0 [active]\n"
"\\_ round-robin 0 [enabled]\n"
"\\_ 0:0:1:1 sdb 8:16 [active]\n"
"\n"
"EVA_SAN2 (3600508b4001044ee0001300003880000)\n"
"[size=300 GB][features=\"1 queue_if_no_path\"][hwhandler=\"0\"]\n"
"\\_ round-robin 0 [active]\n"
"\\_ 0:0:0:2 sdc 8:32 [active]\n"
"\\_ round-robin 0 [enabled]\n"
"\\_ 0:0:1:2 sdd 8:48 [active]\n"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):246
msgid ""
"By default, it will pick the first priority group (the first top round-robin "
"for the EVA_SAN2, for instance, being sdc). In this instance, "
"due to round robin it will bounce back and forth. But if one path was to "
"fail, it would push all information to the other path and continue. Only if "
"all the devices in a path fail will it actually fail and go to the secondary "
"priority group."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(title):257
msgid "Typical Configuration"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):260
msgid "A typical Multipath configuration looks like the following:"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre:caption):264
msgid "A typical /etc/multipath.conf file"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre):264
#, no-wrap
msgid ""
"\n"
"defaults {\n"
"udev_dir /dev\n"
"polling_interval 15\n"
"selector \"round-robin 0\"\n"
"path_grouping_policy group_by_prio\n"
"failback 5\n"
"path_checker tur\n"
"prio_callout \"/sbin/mpath_prio_tpc /dev/%n\"\n"
"rr_min_io 100\n"
"rr_weight uniform\n"
"no_path_retry queue\n"
"user_friendly_names yes\n"
"}\n"
"blacklist {\n"
"devnode cciss\n"
"devnode fd\n"
"devnode hd\n"
"devnode md\n"
"devnode sr\n"
"devnode scd\n"
"devnode st\n"
"devnode ram\n"
"devnode raw\n"
"devnode loop\n"
"devnode sda\n"
"}\n"
"\n"
"multipaths {\n"
"multipath {\n"
"wwid\n"
"(To find your wwid, please use /usr/bin/sq_vpd ?page=di /dev/DEVICE.\n"
"The address will be a 0x6. Remove the 0x and replace it with 3.)\n"
"alias DB_SAN\n"
"}\n"
"devices {\n"
"device {\n"
"(White spacing is important on these two items to match the vendor specifications.)\n"
"\"IBM \"\n"
"\"1815 FAStT \"\n"
"}\n"
"}\n"
"}\n"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(impo):309
msgid ""
"On your devices, it is best to cat/sys/block/sd(device)/device/"
"model and cat/sys/block/device/sd(device)/device/vendor"
"path>, placing both directly into your devices section in /etc/"
"multipath.conf. You might not always see the white spacing, and it's "
"part of the name in this case. One reason for the device section is that not "
"every vendor's string is in the kernel convention and naming, and the "
"string, as such, is not always detected as required."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):320
msgid ""
"A typical multipath configuration utilizing an EVA_SAN where the device "
"information is in the kernel information regarding SAN hardware detection "
"would look like:"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre:caption):326
msgid "EVA_SAN configuration"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(pre):326
#, no-wrap
msgid ""
"\n"
"multipaths {\n"
"multipath {\n"
"wwid 3600508b4001044ee00013000031e0000\n"
"alias EVA_SAN\n"
"}\n"
"multipath {\n"
"wwid 3600508b4001044ee0001300003880000\n"
"alias EVA_SAN2\n"
"}\n"
"}\n"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(title):344
msgid "Setting Up Your Own Configuration"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):348
msgid ""
"The multipath configuration is fairly simple to accomplish because the only "
"file that needs modification is /etc/multipath.conf."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):353
msgid ""
"To begin, set the polling interview to how often (in seconds) path "
"checks will be performed to ensure that the path is alive and healthy."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):358
msgid "selector will be set at \"round-robin 0\"."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(note):362
msgid ""
"This round-robin value is the only selector value that will be used in this "
"configuration."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):367
msgid ""
"prio_callout: This one can be quite important, and there are a number "
"of different priorities for different devices, such as:"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(li):373
msgid "mpath_prio_alua"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(li):374
msgid "mpath_prio_emc"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(li):375
msgid "mpath_prio_hds_modular"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(li):376
msgid "mpath_prio_netapp"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(li):377
msgid "mpath_prio_tpc"
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(note):380
msgid ""
"For most people, mpath_prio_tpc will suffice as it's a conservative "
"checker. Other devices like mpath_prio_netapp have special "
"functionality for priority grouping, such as netapps."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):386
msgid ""
"path_grouping_policy has a few different options: failover, multibus, "
"group_by_prio. Failover will only have one disk per priority group. "
"Multibus will put all devices into one priority group. "
"Group_by_prio is done by a \"priority value.\" So routes that have "
"the same priority value will be grouped together, the priority values being "
"determined by the callout."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):395
msgid ""
"no_path_retry is set to queue as most people don't want data "
"to fail to send at all. So, if all paths fail, for instance, the I/Os will "
"queue up until the device returns and then sends everything again. Depending "
"on your transfer, this can cause load issues."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):402
msgid ""
"rr_min_io are the number of I/Os to do per path before switching to "
"the next I/Os in the same group. If sda and sdb "
"were in the same group, rr_min_io would do 100 I/Os to sda then "
"do 100 to sdb, bouncing back and forth. This is a setting to "
"tweak for each instance to maximize performance because the data load and "
"size of transfers/request vary by company. The default in the case is "
"1000, but some may prefer a smaller number in order to switch ports "
"more often, when possible."
msgstr ""
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(p):413
msgid ""
"user_friendly_names make it easier to see which device you are "
"working with. For example, if you set user_friendly_names to no, then "
"you'll see WWID instead of EVA_SAN for your device."
msgstr ""
#. Place here names of translator, one per line. Format should be NAME; ROLE; E-MAIL
#: ../../gentoo/xml/htdocs/doc/en//multipath.xml(None):0
msgid "translator-credits"
msgstr ""