Meridian Data Excel / Meridian Data Computer Drive 1 Manual De Usuario
S
ECUR
S
TOR
A
STRA
ES
97
To use LUN Affinity you must:
•
•
Have two controllers in the subsystem
•
Enable LUN Affinity under controller settings.
Disk Array Creation
When you create a logical drive using the Advanced method of disk array creation, you can specify the Preferred
Controller ID:
•
Controller ID:
•
Controller 1
– Assign all logical drives to Controller 1
•
Controller 2
– Assign all logical drives to Controller 2
•
Automatic
– Alternate logical drive assignments between Controllers 1 and 2
Automatic is the default and preferred setting because it will balance the logical drive assignments for you.
When you create a logical drive using the Automatic or Express disk array creation, the logical drives are
assigned alternatively between Controllers 1 and 2 automatically.
assigned alternatively between Controllers 1 and 2 automatically.
Logical Drive Settings
After you have created a logical drive, you can click on the Settings tab and manually change the Preferred
Controller ID between Controller 1 and Controller 2.
Controller ID between Controller 1 and Controller 2.
If you create logical drives with LUN Affinity disabled, the Preferred Controller ID will show N/A, and your logical
drives will be visible to both controllers.
drives will be visible to both controllers.
If you create logical drives with LUN Affinity disabled, and later you enable LUN Affinity, all of your logical drives
will be assigned to Controller 1. To balance the load, you can reassign some of your logical drives to Controller 2
under the Preferred Controller ID in the Settings tab.
will be assigned to Controller 1. To balance the load, you can reassign some of your logical drives to Controller 2
under the Preferred Controller ID in the Settings tab.
When you a delete a logical drive, the remaining logical drives keep the same Controller assignments. If you
want to rebalance controller assignments of the remaining logical drives, change their Preferred Controller IDs in
the Settings tab.
want to rebalance controller assignments of the remaining logical drives, change their Preferred Controller IDs in
the Settings tab.
Failover and Failback
When one controller fails, the surviving controller takes over logical drive access until the failed controller is
brought back online or is replaced. For example, LUN Affinity is enabled and your logical drives are assigned to
Controller 1. The following actions will happen:
•
brought back online or is replaced. For example, LUN Affinity is enabled and your logical drives are assigned to
Controller 1. The following actions will happen:
•
If Controller 1 goes offline, Controller 2 takes over access to the logical drives assigned to Controller 1.
•
If Controller 1 comes back online, Controller 1 takes back access to the logical drives assigned to it.
•
If Controller 1 is replaced, the new controller takes over access to the logical drives assigned to Controller 1.
•
All logical drives assigned to Controller 2 remain accessible by Controller 2. Controller 1 cannot access them
at any time.
at any time.
Capacity Coercion
This feature is designed for fault-tolerant logical drives (RAID 1, 1E, 5, 10, 50, and 60). It is generally
recommended to use physical drives of the same size in your disk arrays. When this is not possible, physical
drives of different sizes will work but the system must adjust for the size differences by reducing or coercing the
capacity of the larger drives to match the smaller ones. With Astra ES, you can choose to enable Capacity
Coercion and any one of four methods.
recommended to use physical drives of the same size in your disk arrays. When this is not possible, physical
drives of different sizes will work but the system must adjust for the size differences by reducing or coercing the
capacity of the larger drives to match the smaller ones. With Astra ES, you can choose to enable Capacity
Coercion and any one of four methods.
Enable Capacity Coercion and select the Method in the Controller Settings menu. The choices are:
•
GB Truncate
– (Default) Reduces the useful capacity to the nearest 1,000,000,000 byte boundary.
•
10GB Truncate
– Reduces the useful capacity to the nearest 10,000,000,000 byte boundary.
•
Group Rounding
– Uses an algorithm to determine how much to truncate. Results in the maximum amount
of usable drive capacity.
•
Table Rounding
– Applies a predefined table to determine how much to truncate.