Hitachi G1000 - Pair condition and recovery: P-VOL failure (LDEV blockade)

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Mode Category Description Default MCU/RCU

Mode 897 = ON:

• SOM 898 is OFF: 110%+0IO

• SOM 898 is ON: 110%+2IO

Mode 897 = OFF (Default)

• SOM 898 is OFF: 110%+5IO (Default)

• SOM 898 is ON: 110%+1IO

By setting the SOM s to ON to lower the upper limit for

each tier, the gray zone between other tiers becomes

narrow and the frequency of page allocation increases.

Notes:

1. Apply the mode when the usage of upper tier is low

and that of lower tier is high.

2. The mode must be used with SOM 898.

3. Narrowing the gray zone increases the number of

pages to migrate between tiers per relocation.

4. When Tier1 is SSD while SOM 901 is set to ON, the

effect of SOM 897 and 898 to the gray zone of Tire1

and Tier2 is disabled and the SOM 901 setting is

enabled instead. In addition, the settings of SOM 897

and 898 are effective for Tire2 and Tier3.

Please also see spreadsheet "SOM 897_898_901" for more

details about the relations between SOM 897, 898 and

901.

898

Dynamic Tiering,

Dynamic Tiering

for Mainframe

I/O value (IOPH) can be changed as follows.

Mode 898 = ON:

• SOM 897 is OFF: 110%+1IO

• SOM 897 is ON: 110%+2IO

Mode 898 = OFF (default):

• SOM 897 is OFF: 110%+5IO (Default)

• SOM 897 is ON: 110%+0IO