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Array Candidates |
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Step 2 in creating an array is to select the 'Free' resources which will become the array members, or components.
The attributes chosen in Step 1 are shown, along with a list of suitable candidate disks.
Note: | Candidates are all 'Free' disks which are in the chosen SSA loop. (The Network ID selected in Step 1). |
Note: | If you are creating an array on an adapter that supports Hot Spare Pools, you can assign a pool Id to each of the selected candidates. |
RAID 1/10 - Multiple Domains & Component Order
(IBM Advanced SerialRAID/X Adapter Only)
Terminology:
When you are creating a RAID-1 array, you cannot change the Component Order. The candidate which is closest to the top of the list of candidates will always be the Primary Domain (disk) and the Secondary Domain (disk) will be the next selected candidate.
When you are creating a RAID-10 array, you can also assign the Component Order. This allows you to control which candidates will become mirrored pairs within the array.
RAID 10 uses mirrored stripe sets, where the data is striped across a set of drives (The stripe set). At the same time, the stripe set is mirrored to another set of disks. Using this method of redundancy allows multiple domains to be created within one array.
RSM provides component ordering to allow you to create two domains within an array which has an even number of component disks, or members. Each domain contains a copy of the entire stripe set. One domain is assigned as the Primary, the other being the Secondary. As long as the Primary Domain is accessible, the array can continue to process read and write requests, even if the Secondary Domain has been lost.
Consider when assigning the array component order if multiple domains are to be used. For example, you can physically separate one domain from the other. i.e. in a different enclosure, in a different building and so on. Thus, power failing in one enclosure, or building will not take the array offline.
The secondary domain will be prevented from continuing if it
loses contact with the primary domain and the
Split Resolution attribute is set to 'Off'.
If you do not wish to use multiple domains leave the
component order as 'default'
Note:
Note:
Assigning Component Ordering:
RSM component ordering allows you to pick the candidates that will become members of each domain if the following rule is followed :
The data written to the disk 'X (Primary)' is always mirrored on 'X (Secondary)' - where X is any value between 1 and 8.
For more information regarding RAID10, multiple domains, and Hot-spare pools, read the relevant chapter in your adapter User's Guide See also the RSM Tutorial.
Candidate Attributes:
Check Box: (The button in the first table cell of
each row.) Use these to select the array members.
The correct number must be selected prior to committing the 'Create'
action.
Note:
Disk:1 The name of the physical disk.
Serial Number: The unique identifier for this disk.
Size: The capacity of the disk, in gigabytes.
Status: The resource status, see the status list for a list of valid states.
Network ID: The SSA Loop that the candidates participate in.
Actions:
These drop down boxes contain a list of all the available
Hot-spare Pools on the chosen SSA loop. Select the pool
you wish to use to protect each of the array members. (Default is the Global pool on the chosen loop.) These drop down boxes contain a list of the valid component
ordering for the selected number of array components. Select
the ordering as explained above, if you wish to use multiple
domains, otherwise leave them as 'default'. (The button in the first table cell of
each row.) Use these to select the array members.
The correct number must be selected prior to committing the 'Create'
action. This action submits the chosen candidates and attributes for the
adapter to complete the array creation. If any error occurs, a suitable message
will be displayed in the Information Area. This action displays the RAID-10 Confirmation page. If you have chosen to create your RAID-10 array using multiple domains this page allows you to check that you have assigned the resources to the correct domain. You can flash the indicator lights on either half of the array as part of this confirmation. This action aborts the array creation and returns you to the
Resource List
Related Information
Note:
Pool ID
Component Order
Check Box
Note:
Create
Confirm
Cancel