Fujitsu DX440 S2 Computer Drive User Manual


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Chapter 5 Volume Management
5.2 Functions in the Action Area for Volume
ETERNUS Web GUI User’s Guide
Copyright 2013 FUJITSU LIMITED P2X0-1090-10ENZ0
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Multi Writeback Count (MWC)
Specify the number of processes that can be written back at the same time.
Prefetch Sequential Detect Count (PSDC)
Specify the number of times for sequential data detection to determine the sequentiality of data access
(Read IO).
Sequential Dirty Detect Count (SDDC)
Specify the number of times for sequential data detection to determine the sequentiality of data access
(Write I/O).
Sequential Slope (SS)
A parameter to determine the sequentiality of data access (Read I/O). Specify the number of LBAs by which
the previous I/O and the current I/O are considered as sequential data.
Sequential Dirty Slope (SDS)
A parameter to determine the sequentiality of data access (Write I/O). Specify the number of LBAs by which
the previous I/O and the current I/O are considered as sequential data.
The procedure to modify cache parameters is as follows:
Procedure
1 Select which volume to change the cache parameters for (multiple selections can be made)
and click [Modify Cache Parameters] in [Action].
2 Change the cache parameters and click the [Modify] button.
Refer to " Volume types for which Cache Parameters are available" (page 153) for the volume types for
which the parameters can be specified.
Cache Page Capacity
Specify the cache capacity that is used by volumes.
- "-" (hyphen)
- 32.50 MB
- 65.00 MB
- 130.00 MB
- 260.00 MB
- 520.00 MB
- 1040.00 MB
- 2080.00 MB (Not available for the ETERNUS DX80 S2)
For TPVs, specify the MWC for each TPP. Refer to "7.2.8 Modify Cache Parameters (Thin Provisioning Pool)"
(page 241) for details.
Cache parameters cannot be changed when pinned data exists in the ETERNUS DX Disk storage system.
The same cache parameter can be applied for multiple volumes in a single operation.