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: Create a workload
profile with the mkprofile command. |
Syntax

>>-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:
- Create a workload profile with the mkprofile command.
- 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.
- 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.
- Volumes recommendation: xxx Vdisks or volumes
of 50 GB each. (The value for xxx is the number of
volumes recommended.)
- For each task, the following information is listed in either tabular or
multi-row table format:
Column Label |
Details |
Utilization |
Available capacity, such as low, medium, or high. |
Device |
Device ID (nickname or model-serial-manufacturer) |
Location |
Array ID |
Volume |
Volume ID (if volume reused; else a dash) |
Size (GB) |
Size in GB |
RAID Level |
RAID-X or JBOD |
Possible failures
- Profile profile_name does not exist.
- LUNs are not all of the same device type.
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.