Multiple Tiering policies can be created. It is also possible to define the same Tiering policy to multiple Tier pools.
The items which can be specified as Tiering policy are as follows.
Item | Specification | Explanation |
|---|---|---|
Policy Name | Required | Specify a name (that is unique within the ETERNUS SF system) for the Tiering policy that is being created. Any alphanumeric character (1 - 16 characters), a hyphen (-), an underscore (_), and a pound symbol (#) may be specified. The letters to be specified are not case sensitive. |
Execution Mode | Optional | Specify the execution mode which specifies the method for operation of Automated Storage Tiering.
|
Evaluation Period | Optional | Specify the evaluation range of the performance data for Automated Storage Tiering. Select a number and a unit ("Hour", "Day", or "Week"). The default setting is "1 Day". When the unit is "Hour", 2, 4, 6, 8, or 12 may be specified. The starting point of the evaluation period varies depending on the setting of Execution Mode. If Execution Mode is "Auto" or "Semi-Auto", the starting point of the evaluation period is 0:00. For example, if "6 Hour" is specified, the evaluation is conducted from 0:00 - 6:00, 6:00 - 12:00, 12:00 - 18:00, and 18:00 - 24:00. When the selected unit is "Day", a value within the range of 1 - 31 may be specified. When the selected unit is "Week", 1 may be specified. |
Evaluation Standard | Optional | Specify the standards for the evaluation of the performance for Automated Storage Tiering. From the pull-down list, select either of the following:
|
Evaluation Day | Optional | Specify the day of the week to start evaluation of the access status data. This can be specified only when Execution Mode is set to "Auto" or "Semi-Auto" and the unit of Evaluation Period is set to "Week". When the Evaluated from initial specified day (Evaluated despite insufficient Evaluation Period) checkbox is checked, even if the evaluation period is insufficient, an evaluation is performed using access status data that exists by the specified day of the week for the first time. Check this checkbox when it is desirable to immediately start operation of Automated Storage Tiering. The default setting for this checkbox is not checked (recommended). When this checkbox is not checked, an evaluation is not performed on the specified day of the week for the first time, and from the next specified day of the week, evaluations is always performed using access status data for the evaluation period. |
Automated Storage Tiering Execution Time | Optional | Specify the time, within the range of 0:00 - 23:59, to start collection, evaluation, and relocation of performance data for Automate Storage Tiering. When the unit of Evaluation Period is set to "Hour", the process is executed at the time after the specified number of hours (2, 4, 6, 8, or 12 hours) has elapsed from 0:00. |
Automated Storage Tiering Time Limit | Optional | Specify the time to discontinue the volume relocation as elapsed time from the time specified in Automated Storage Tiering Execution Time. The default setting is "no limit" (process is not discontinued). When the unit of Evaluation Period is "Day" or "Week", a value from 00 through 24 may be specified. |
Days of the Week subject to Evaluation | Optional | Upon execution of relocation, specify the day of the week to collect performance data for Automated Storage Tiering that is subject to evaluation. This can be specified only when the unit of Evaluation Period is set to "Day" or "Week". In the default setting, all days of the week are subject to evaluation. The days of the week that are checked off are excluded from being subject to evaluation. |
Time of the Day subject to Evaluation | Optional | Specify the time of the day to collect and evaluate performance data for Automated Storage Tiering. This can be specified only when the unit of Evaluation Period is set to "Day" or "Week". The default setting is "24 Hours" (the 24 hours from 0:00 to 0:00). For both the starting time and the ending time of evaluation, a value from 0:00 to 23:00 may be specified. |
Configure Evaluation Excluded Day | Optional | Specify the day, with a calendar, to be subject to evaluation of performance data for Automated Storage Tiering. This can be specified only when the unit of Evaluation Period is set to "Day" or "Week". In the default setting, the Enable checkbox is checked on. While in this state, the date to be subject to evaluation may be specified with the calendar that is displayed by clicking Edit Evaluation Excluded Day. When the Enable checkbox is checked off, the configuration of evaluation excluded day becomes void. |
Data Type | Optional | Select the type of performance data used for evaluating Automated Storage Tiering. Only IOPS (read/write operations per second) can be specified. |
Data Range of Layer | Optional | Specify whether to manually configure the data range of each layer or to have the system automatically configure this. In the default setting, the Automatic Configuration checkbox is checked on. When set to automatic configuration, Data Range of Low, Data Range of Middle, and Data Range of High cannot be specified. The system automatically decides relocation standards. When the Automatic Configuration checkbox is checked off, the date range for each layer can be manually configured. |
Data Range of Low | Optional | Specify the range of the IOPS values to use as standards for location to the Low sub-pool of the Tier pool. For this item, specify a maximum value. It is also possible to enter a decimal value. The minimum value is fixed at "0", and a "-" is displayed in the Main pane of the Tiering policy. When this specification has been omitted, a "-:-" is displayed in the Main pane of the Tiering policy. (*2) |
Data Range of Middle | Optional | Specify the range of the IOPS values to use as standards for location to the Middle sub-pool of the Tier pool. For this item, specify a minimum value and a maximum value. It is also possible to enter a decimal value. When this specification has been omitted, a "-:-" is displayed in the Main pane of the Tiering policy. (*2) |
Data Range of High | Optional | Specify the range of the IOPS values to use as standards for location to the High sub-pool of the Tier pool. For this item, specify a minimum value. It is also possible to enter a decimal value. The maximum value is fixed at "2,147,483,647", and a "-" is displayed in the Main pane of the Tiering policies. When this specification has been omitted, a "-:-" is displayed in the Main pane of the Tiering policy. (*2) |
*1: When a specification is omitted for the item of which specification is "Optional", a default value is configured.
*2: In cases when a range has not been specified, relocation is performed automatically by the system.
Refer to "Create Tiering Policy" in the ETERNUS SF Web Console Guide for information on how to create Tiering policies.
Point
When the Execution Mode is set to "Auto" and the Data Range of Layer is set to "Automatic Configuration", the system automatically decides the standards for relocation of data within the volume, and optimally perform the relocation. Normally, specification with this combination is recommended.
When setting the Data Range of Layer to the manual configuration, in order to assess the optimal value for the data range of each sub-pool, it is recommended that the Execution Mode is set to "Semi-Auto" or "Manual" and test runs of evaluation and relocation are performed.
Example
It explains timing from which the evaluation and relocation are executed according to the Tiering policy by using the following examples.
It is an example of executing the Automated Storage Tiering based on the access status at 8:00-17:00 at 18 o'clock every day.
Evaluation Period is set to "1Day", Time of the Day subject to Evaluation is set at 8:00-17:00, and Automated Storage Tiering Execution Time is set to 18:00.
The evaluation to the access situation data of 8:00-17:00 is begun at 18:00 every day.
It is an example of executing the Automated Storage Tiering among one week based on the access status from Monday to Friday at 0 o'clock of Saturday.
Evaluation Period is set to "7Day", Day of the Week subject to Evaluation is set on Monday - Friday, and Automated Storage Tiering Execution Time is set to 0:00.
The evaluation to the access situation data of Monday - Friday is begun at 0:00 the following Saturday on the seventh every week when Automated Storage Tiering to the Tier pool of 0:00 of Saturday begins.
It is an example of executing the Automated Storage Tiering based on the access status of eight hours every eight hours.
Evaluation Period is set to "8Hour".
The evaluation to the access situation data of six hours from 2:00 to 8:00 is begun at 8:00 when Automated Storage Tiering to the Tier pool of 2:00 begins to make 0:00 a starting point for the Evaluation Period. Eight hours until 16:00-24:00 are evaluated to 24:00 for eight hours until 8:00-16:00 at 16:00
after that.
This is an example of executing Automated Storage Tiering at 0:00 on Saturdays based on access status from Monday through Friday.
Specify 1 week for Evaluation Period, Monday through Friday for Days of the Week subject to Evaluation and 0:00 for Automated Storage Tiering Execution Time. Regardless of the date and time that Automated Storage Tiering is started, evaluation is not performed on the first Saturday but started at 0:00 the following Saturday based on the access status for one week from Monday through Friday from the first Saturday.
If Automated Storage Tiering is started on Tier pool at 0:00 of Thursday, the result is as follows:
To use Automated Storage Tiering immediately after starting Automated Storage Tiering, specify Evaluated from initial specified day (Evaluated despite insufficient evaluation period).
If Automated Storage Tiering is started on Tier pool at 0:00 of Thursday, the result is as follows:
Evaluation of access status data for 2 days from when Automated Storage Tiering was started until the first Saturday is started at 0:00 of the first Saturday. The evaluation from the next time on is started at 0:00 of every Saturday for access status data for 5 days from Monday through Friday.
Note
Evaluation Day can be specified only when Execution Mode is Auto or Semi-Auto and the unit of Evaluation Period is Week.
If Evaluated from initial specified day (Evaluated despite insufficient evaluation period) is specified and evaluation is executed in shorter than evaluation period, unintended consequences of evaluation may be output due to a small amount of access status data.
Even if Evaluated from initial specified day (Evaluated despite insufficient evaluation period) is specified to start Automated Storage Tiering, evaluation and relocation are not performed in the following cases:
Access status data is not collected for one or more days (24 hours).
Period of collecting access status data is all specified for Configure Evaluation Excluded Day.
Period of collecting access status data is all specified for Evaluation Day.
