EMC, HP, DELL 등의 특정한 벤더의 스토리에 맞는 멀티패스는 어떻게 구현할까?
multipath 패키지와 함께 설치되는 multipath.conf.annotated 파일을 참고해서 작업하면 된다.
그렇게 설정되지 않는 경우에는 각 벤더사 사이트에서 제공되는 설정값들을 확인해야 한다.
예 ) HP 스토리지 장비별 multipath 구성 설정방법
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=115&prodSeriesId=3559651&prodTypeId=18964&objectID=c01476873
Multi-path Device Mapper for Linux Software - Software Configuration
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
multipathdevice:
- 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:
- Copy the /usr/share/doc/HPDMmultipath-tools-4.0.0/multipath.conf.HPTemplatefile as /etc/multipath.conf
For SLES systems:
- 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 multipathssection defines the multipath topologies. They are indexed by a World Wide Identifier (wwid). Thedevices 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 kernelmpath 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), failindicates immediate failure (no queuing), or queueindicates 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 thevendor 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 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, themultipathd 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:
- Run multipath utility.
- Use the # /sbin/multipath -ll option.
