mkrecom

Use a profile and the mkrecom command to generate a performance LUN advisor allocation recommendation for ESS volumes and, optionally, to apply the recommendation.
Note:Note: Create a workload profile with the mkprofile command.

Syntax

Read syntax diagramSkip visual syntax diagram>>-perfcli-- --mkrecom-- ---profile--profile_name-- ------------>

>---space--total_space--+----------------+---------------------->
                        +--size--min:max-+
                        '--num--min:max--'

>--+---------------------------+-- --+---------------------+---->
   '--dev----deviceIDs [...]---'     '--hosts--host:device-'

>-- --+---------------------------+-- -------------------------->
      '--exclude-- LUNs--[. . . ]-'

>--+---------------------------+-- --+--------------+-- -------->
   '--include--LUNs-- [. . . ]-'     '--seed--value-'

>--+--------+--------------------------------------------------><
   '--quiet-'

Parameters

-profile profile _name
Specifies the volume advisor workload profile that is to be used during the allocation recommendation process. This profile contains specific performance requirements.
space total_space
Specifies total LUN space required, in GB, as the volume advisor makes an allocation recommendation. The minimum value is 0.1 GB; the maximum value is device dependent.
-size min:max
An optional parameter that specifies the minimum and maximum target LUN sizes to be used, in GB, during LUN allocation. The minimum number and maximum number must be separated by a colon with no space between the numbers. You must specify either -size or -num when using the mkrecom command. However, the -size parameter cannot be used when the -num parameter is used. The minimum value is 0.01 GB and the maximum value is 450 GB.
-dev deviceIDs [...]
An optional parameter that restricts the allocation recommendation to the devices specified. All devices will be included unless otherwise specified.
-num min:max
An optional parameter that specifies the minimum and maximum number of target LUNs to be used, in GB, during LUN allocation. The minimum number and maximum number must be separated by a colon with no space between the numbers. You must specify either -size or -num parameter when using the mkrecom command. However, the -num parameter cannot be used when the -size parameter is used. You must specify a minimum volume size of 0.1 GB.
-hosts host:device
An optional parameter that restricts the volume advisor allocation recommendation to the hosts specified. A fully qualified host ID is required and must include device ID. Separate multiple fully-qualified values with commas and no white space between the values. If a fully qualified ID is not available, then the host name and device ID can be indicated by separating each value with a colon.
-exclude LUNs [ . . . ]
An optional parameter that restricts the volume advisor recommendations from using the LUN or set of LUNs specified for an allocation. The volume advisor considers all available LUNs except those specified with the -exclude parameter. All LUNs must be of the same device type. You can specify LUNs at various device levels, such as clusters, adapters, arrays, nodes, MDisk groups and so forth. The -exclude parameter cannot be used with the -include parameter.
-include LUNs [ . . . ]
An optional parameter that specifies a LUN or set of LUNs that is to be used during the volume advisor recommendation. The volume advisor only considers the LUNs specified with the -include parameter. All LUNs must be of the same device type. You can specify LUNs at various device levels, such as clusters, adapters, arrays, nodes, MDisk groups and so forth. The -include parameter cannot be used with the -exclude parameter.
-seed value
An optional parameter that specifies a seed value for the random number generator. To allow two consecutive mkrecom commands to return the same recommendation when the same mkrecom inputs are provided (assuming that the configuration and I/O behavior has not changed in the time between the two mkrecom invocations), the same seed value needs to be specified
-quiet
An optional parameter that turns off the confirmation prompt for this command.

Description

Use a profile and the mkrecom command to generate a performance LUN advisor allocation recommendation for ESS volumes and, optionally, to apply the recommendation. The mkrecom command generates a list of optimal logical unit numbers (LUNs) that can be used for a given storage request.

Notes:
Notes:
  1. Create a workload profile with the mkprofile command.
  2. Recommendations can apply to either preallocated or nonallocated storage. If the recommendation includes space that is not allocated yet, applying the recommendation automatically creates the LUNs necessary to implement the recommendation.
  3. Use the -seed parameter to specify a seed to initialize the random number generator. This ensures that not all new volumes get added to the same component when multiple components have the same cost factors associated with them. This means that if you run the advisor twice in a row, with identical input, you will probably get different, but equally good, advice. To ensure that you get the same advice both times in a row, you can specify the same seed value to cause selection of the same random numbers both times you invoke the mkrecom command.

Return values

The following message and a table are both returned.

Possible failures

Examples

An invocation example:

perfcli mkrecom -profile profile4 -space 300 GB

The resulting output:

Name      Util  Device Location Vol Size (GB) RAID  Host 
============================================================
profile4   low  ESS6    array4   15     20  RAID-5   HewlttPackard3   

Would you like to apply this recommendation now? y/n
y

15 volumes  created. 

Related topics

(C) Copyright International Business Machines Corporation 2004