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SSA RSM Tutorial - Overview


What is RSM?

RSM is an SSA configuration and management tool that allows an administrator to configure and maintain SSA systems safely via a browser. The browser can run on any machine that is networked to the administrator's SSA server. (In this summary, SSA server means either the server that runs the RSM NT Service, or the TME10 Netfinity Web Services)

RSM allows local and remote configuration. You can perform local configuration if you run a browser on the SSA server itself. You can perform remote configuration if you run a browser on any machine that is on the SSA server network. For both conditions, use the following URL used to access RSM :

http://<your tcpip address>:511/ssa (Stand Alone Version)
http://<your tcpip address>:411/ssa (Netfinity Version)
(All future URL references will be made to port 511, if you are running the Netfinity Version, replace with 411 as appropriate)

You can also access RSM, RSM help, this tutorial, readme documents, and other IBM SSA services via URL :

http://<your tcpip address>:511/index.htm

Or you can click on the SSA Tools icon that has been created in your Start Menu.

With RSM, you can perform all the actions that you previously did with the IBM SSA NT Text-based configurator (ISSACFG.EXE ) and many more.

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SSA Terminology

Configurations

You can configure your SSA system in various ways (if your adapter provides support for them). These are :

Resource Characteristics : Type, Usage and State

SSA Resources have a "type", indicated by different resource icons and a "usage", indicated by the colour of these icons.

Types

RAID Array - An array is a resource created from Non-RAID Disk resources. Each IBM SSA adapter supports a different sub-set of the following RAID types. Check the documentation supplied with your adapter(s) for details.
A Non-RAID Disk (or Resource) is a resource which is simply a single SSA disk.

RAID 0 is also known as STRIPING. Such an array will provide a broad bandwidth for processing large data files.
RAID 1 is also known as MIRRORING or DUAL COPY. This provides the highest assurance of data availability but requires real disk capacity of twice the data size.
RAID-5 arrays implement data stripping and provide protection against drive failures (redundancy) by storing parity information. For an array with N+1 components there is one parity strip for every N data strips. The parity strip is calculated by performing an `exclusive or' of the data in all of the associated data strips.The parity and associated data strips are always stored on different components of the array so that in the event of a drive failure which prevents a data strip being read the parity and remaining data strips can still be read from the other components. Using the parity and other data strips the data on the bad drive can be reconstructed by performing an `exclusive or' of the parity with the remaining data strips.

Every time data is written to a RAID-5 array both a data strip and the corresponding parity strip must be updated. If all the parity in an array was stored on one drive this would mean that every write operation would require to write data to the parity drive and consequently performance would be limited by the speed at which the parity data can be written. To prevent this bottleneck RAID-5 arrays distribute parity strips across different components of the array.

RAID 5 provides redundancy with good performance for reading large or small data files. Data can be reconstructed in the event of one member failure. However, due to the "read/modify/write" penalty in updating parity during write operations, the write performance is not as good as with other RAID options.

RAID-10 arrays implement data stripping and mirroring. That is, data is striped across a set of disks, and the same striping is made to a duplicate set of disks. This allows multiple domains to be created within a RAID-10 array in such a way that if one half, or domain, of the array becomes unavailable, the other domain can continue to perform read and write operations. See the RAID10 and Hot-spare Manager Tutorial.
Hot-spare Pools can be used to protect arrays against disk failures. These are only available with the IBM Advanced SerialRAID/X Adapter See the RAID10 and Hot-spare Manager Tutorial.
A Non-RAID Disk
Within RSM, NVRAM entries are also classed as resources, although generally no user configuration is possible, the exception being deleting "dormant" entries. See description in Logical View section for more details.
Again within RSM, Enclosures, and their constituent parts are classed as resources. See Enclosure View section for more details.

Usage

Free
(Blue)
A Free Resource is one which is not currently used for any purpose. It can be assigned a use, or used to construct other types of resource (such as RAID array resources and Fast Write resources).
System (AIX)
(White)
(N.B. The DOS and NT Text-based configurators refer to such resources as "New") A System (AIX) resource is normally one which is new from the factory. It can also be a resource which has been used in a non-PC environment (such as AIX). Also, resources which are members of array types not supported by the current adapter get classified as System (AIX), with the word "Preconfigured" displayed next to them.
Finally, if two System Resources with the same Resource Number are accidentally connected to an adapter, one will be listed as a System (PC) Resource and the other will be listed as a System (AIX) Resource.
System (PC)
(Green)
A System Resource is one which the operating system can access. Every System Resource has a unique Resource Number, which the operating system uses to distinguish between resources. System Resources are presented to the system in ascending order of Resource Number.
Unknown
(Transparent & Blue ?)
The adapter is unable to determine the type or usage of the resource. Consult the Hardware Maintenance Manual supplied with your adapter if you have any Unknown resources.
Rejected
(Red)
A Rejected Resource is one which used to be a member of an array resource, but no longer is. Arrays reject member resources if they fail or are found to contain corrupt data. If an array loses a component, replacing it with a Hot Spare, and the original component returns, it too will be Rejected.
Hot Spare
(Yellow)
A Hot Spare Resource is one which is currently not in any active use. If a (suitably configured) array resource loses one of its component resources, the Hot Spare Resource can be taken and used to replace the failed / missing component.

State

All resources can also be in one of two "states", online and offline.

Offline Non-RAID Disk A Non-RAID Disk will go offline only for a short time if the resource is unavailable but the device driver still has an open handle.
Offline RAID 0 Array An array will go offline if two or more (one or more for RAID 0) of its member resources are unavailable, or if one of its member resources is unavailable during a rebuild process.
Note: Similar icons exist for RAID 1 and RAID 5.

Arrays can also be in two further "states", degraded or exposed.

Degraded / Exposed Free RAID 0 Array An array will first become Degraded if one of its member resources is unavailable. Upon the first attempted write to a Degraded array, the state will change to Exposed. Both of these states are depicted by the same icons (half red, half colour - depends upon array usage - this one is free). You can tell if the array is Degraded or Exposed by looking at either the Resource List or the Resource View.
Note: Similar icons exist for RAID 1 and RAID 5.
Degraded / Exposed System RAID 0 Array As above but this is array has a usage of System (PC).
Note: Similar icons exist for RAID 1 and RAID 5.

Examples
These three classifications, type, usage and status are combined to give the current characteristics of a resource, for example :

would be an online, system (PC) RAID5 array,
would be a degraded / exposed, free RAID 5 array,
would be an online, hot spare Non-RAID Disk, etc...

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Design Concepts

RSM Page Layout:

The RSM page layout is designed around the Netfinity Web Services format.

Page Layout

  1. The left hand frame, the explorer frame, contains an expandable tree of SSA adapters and their resources. The resources are grouped by resource type.

  2. The common navigation frame, above the explorer frame contains links to the RSM functions which are available from every RSM page.

  3.  

    The right hand frame, the configuration frame, contains several sub-areas. The style of each sub-area is constant throughout RSM.

  4. The navigation area contains a links to the main RSM resource views; System View, Logical View, Physical View, and Enclosure View. It also contains a logically back button, and a link to the relevant help page.

    You must first select an adapter from the Adapter List page before you can select any of the Logical, Physical, or Enclosure Views. If you have not yet selected an adapter, the buttons will be greyed out.
    Note:

    Logically back means to go back one logical step. For example, if you are in the middle of creating an array (a procedure that contains several steps), and you select the logically back button, you will return to the page where you selected Create Array.

  5. The information area contains reports of user errors, warnings, and (after some actions) important information . These messages appear only once. For example, if you are in a Resource View, and select FlashOn for the resource, a message appears to verify that the resource if flashing. When you move elsewhere, the message disappears. It does not reappear, although the resource may still be flashing.

  6. The title area contains links to other Views and CheckLevels (where appropriate). The page title contains the name of the resource you are configuring or viewing (for example, an adapter or drive serial number).

  7. The configuration area contains the relevant details for the resource that you are observing. It also contains user input forms (where appropraite).

  8. The actions area contains all the actions you can perform on or with the resource that you are viewing.

There are four main views within RSM.

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Local Configuration

Although some adapters are supplied with the IBM SSA Text-based configurator (ISSACFG), it is recommended that ALL users move to use RSM even for local configuration purposes. ISSACFG does not support the IBM SerialRAID Adapter, and will not support any future IBM SSA products.

Local configuration of SSA resources can be performed by accessing the URL:

http://<your tcpip address>:511/ssa

You must have the correct security access to allow configuration of SSA resources.

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Remote Configuration

RSM provides remote configuration of SSA resources via an Intranet or the Internet, provided the client machine (where the browser is running) is networked to the SSA server.

Remote configuration of SSA resources can be performed by accessing the same URL:

http://<your tcpip address>:511/ssa

You must have the correct security access to allow configuration of SSA resources. Due to the remote nature of RSM, security is of utmost importance. All administrators are advised to remove the default SSA user from RSM as soon as you create a new user with Admin access. If you delete the SSA user first, you will not be able to access the service.

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Help

Within RSM, each page contains a help icon in the navigation area. Simply click this icon to open the RSM Context-sensitive help window. The help will automatically move to the area of the file relevant to the currently viewed RSM resource page / view.

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RSM Code Updates (Check Levels)

For users with access to the Internet, RSM provides various code update / check level functions. Clicking on a Check Level link will open a new browser window.

We strongly recommended you regularly use these functions and also visit the SSA Customer Support Homepage directly for updates and other IBM SSA innovations.

http://www.hursley.ibm.com/ssa/

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