Tier monitoring and relocation cycles
Performance monitoring and tier relocation can be set to execute in one of two execution modes:
Auto and Manual. You can set up execution modes, or switch between modes by using either
Remote Web Console or RAID Manager.
In Auto execution mode, monitoring and relocation are continuous and automatically scheduled.
In Manual execution mode, the following operations are initiated manually.
•
Start monitoring
•
Stop monitoring and recalculate tier range values
•
Start relocation
•
Stop relocation
In both execution modes, relocation of data is automatically determined based on monitoring
results. The settings for these execution modes can be changed nondisruptively while the pool is
in use.
Auto execution mode
Auto execution mode performs monitoring and tier relocation based on information collected by
monitoring at a specified constant frequency: from 0.5, 1, 2, 4, or 8 hours. All Auto execution
mode cycle frequencies have a starting point at midnight (00:00). For example, if you select a 1
hour monitoring period, the starting times would be 00:00, 01:00, 02:00, 03:00, and so on.
As shown in the following table, the 24-hour monitoring cycle allows you to specify the times of
day to start and stop performance monitoring. The 24-hour monitoring cycle does not have to start
at midnight. Tier relocation begins at the end of each cycle. For more information, see
.
Finish Times
Start Times
Monitoring cycle (hours)
0.5 hours after the start time
0.5 hours from 00:00 AM. For example
00:00, 00:30, and 01:00
0.5
1 hour after the start time
1 hour from 00:00 AM. For example
00:00, 01:00, and 02:00
1
2 hours after the start time
2 hours from 00:00 AM. For example
00:00, 02:00, and 04:00
2
4 hours after the start time
4 hours from 00:00 AM. For example
00:00, 04:00, and 08:00
4
8 hours after the start time
8 hours from 00:00 AM. For example
00:00, 08:00, and 16:00
8
Specified time
Specified time
24 (monitoring time period can
be specified)
If the setting of the monitoring cycle is changed, performance monitoring begins at the new start
time. The collection of monitoring information and tier relocation operations already in progress
are not interrupted when the setting is changed.
Example 1: If the monitoring cycle is changed from 1 hour to 4 hours at 01:30 AM, the collection
of monitoring information and tier relocation in progress at 01:30 AM continues. At 02:00 AM
and 03:00 AM, however, monitoring information is not collected and tier relocation is not
performed. From 04:00 AM, the collection of monitoring information and tier relocation operations
are started again. These operations are then performed at 4-hour intervals.
Example 2: If the monitoring cycle is changed from 4 hours to 1 hour at 01:30 AM, the collection
of monitoring information and tier relocation in progress at 01:30 AM continues. From 04:00 AM,
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Configuring thin provisioning