HP 스토리지 장비(HP EVA/MSA/HSV )별 multipath 구성 설정방법

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HP 스토리지 장비별 multipath 구성 설정방법

Multi-path Device Mapper for Linux Software - Software Configuration

	Using /etc/multipath.conf File
	HP Recommended configuration parameters
	Recommended Values for HP Arrays
	Starting HPDM Multipath

Using /etc/multipath.conf File

The first step of configuring HPDM Multipath involves editing the /etc/multipath.conf configuration file, which is distributed as part of the HPDM Multipath tools user space package. This file also enables you to customize HPDM Multipath for a variety of SAN storage subsystems .

The multipath.conf file provides the following options to configure the attributes of a multipath device:

• I/O grouping policy
• Polling interval for subsequent path status verification
• Path selector algorithm
• Program used by multipath to obtain a unique path identifier

The HPDM Multipath package comes with a template file with the recommended configuration for HP supported arrays. To use this template file:

For RHEL systems:

1. Copy the /usr/share/doc/HPDMmultipath-tools-4.0.0/multipath.conf.HPTemplate file as /etc/multipath.conf

For SLES systems:

1. Copy the /usr/share/doc/packages/HPDMmultipath-tools-4.0.0/ multipath.conf.HPTemplate file as /etc/multipath.conf

The /etc/multipath.conf file consists of the following sections, to configure the attributes of a multipath device:

• System defaults (defaults )
• Black-listed devices (devnode_blacklist/blacklist )
• Storage array model settings (devices )
• Multipath device settings (multipaths )
• Blacklist exceptions (blacklist_exceptions )

The defaults section defines default values for attributes which are used whenever required setting is unavailable. The blacklist section defines which devices should be excluded from the multipath topology discovery. The blacklist_exceptions section defines which devices should be included in the multipath topology discovery, despite being listed in the blacklist section. The multipaths section defines the multipath topologies. They are indexed by a World Wide Identifier (wwid). The devices section defines the device-specific settings based on vendor and product values.

HP Recommended configuration parameters

Attribute	Description	Supported values
path_grouping_policy	Used for applying the policy to the multipath device hosted by this storage controller	multibus: All valid paths in one priority group group_by_prio: One priority group per path priority value
path_checker	Used for determining the state of the path	tur
path_selector	Used to select the path selector algorithm to be used for mpath . These algorithms are offered by the kernel mpath target	round-robin 0
failback	Used to manage the time during path group failback	immediate
prio_callout	Executable to obtain a path weight for a block device. Weights are summed for each path group to determine the next path group to be used in case of path failure	/bin/true /sbin/ mpath_prio_alua %n
rr_weight	Used to assign weights to the path	uniform
no_path_retry	(n =12) indicates the number of retries until queuing is disabled (queues till n number of polling), fail indicates immediate failure (no queuing), or queue indicates never stop queuing (queue forever till the path comes alive)	n=12

Recommended Values for HP Arrays

The product string of the storage controller contains 16 characters (including spaces) and the vendor string contains 8 characters (including spaces) in the /etc/multipath.conf file. To ease the task of manually editing the devices section of the multipath.conf file, the wild card, regular expression‎ support for the product and vendor string is provided. For example, in /etc/multipath.conf file, the product string for the HSV101 arrays is given the value of HSV101* , instead of HSV101 \(C\)COMPAQ .

For EVA3000-(HSV101)

For EVA4000/6000 - (HSV200)

For EVA5000-(HSV111)

For EVA8000 (HSV210)

For EVA4400 (HSV300)

For MSA A/A arrays

For MSA2000 Storage Product Family arrays

NOTE:

For MSA 2000 Storage Product Family arrays (MSA2012fc/MSA2212fc/MSA2012i, add the device section in /etc/multipath.conf file.

For XP arrays

NOTE:

In XP arrays, there are different LUNs, such as OPEN- , 3390-3A , 3390-3B , OP-C:3390-3C , 3380KA , 3380-KB , and OP-C:3380-KC where x = {3,8,9,K,T,E,V} . The product strings for XP LUNs are based on these emulation types. A new device section must be added for each emulation type, because each product string requires a new device subsection. OPEN-* is sufficient for the product string for all the XP LUNs with different OPEN emulations, because regular expressions are supported in the /etc/multipath.conf file.

CAUTION:

After editing the /etc/multipath.conf file for HP StorageWorks Arrays, you must restart multipathd daemon and run multipath command.

Starting HPDM Multipath

Whenever an attribute for the LUNs of any of the HP supported storage arrays changes, the multipathd daemon must be restarted and the configuration must be reloaded by executing the following commands:

# /etc/init.d/multipathd restart

# /sbin/multipath

These steps are required only if the attributes are modified.

To view the status of the multipath devices, complete the following steps:

1. Run multipath utility.
2. Use the # /sbin/multipath -ll option.

3. Click here for information on status maps in multipath -ll for HPDM Multipath devices in Chapter 4 - "Using HPDM Multipath".

   Device Mapper Multipath Configuration Guide for HP StorageW.pdf