IBM FileNet P8, Version 5.2.1            

IBM Tivoli Storage Manager magnetic tape support

The Content Platform Engine supports writing and retrieving content that is stored on a magnetic tape device within an IBM® Tivoli® Storage Manager server. The Content Platform Engine writes content to the magnetic storage tier in the IBM Tivoli Storage Manager server. At a later time, the IBM Tivoli Storage Manager migrates the content to a tape device.

Magnetic tape is a sequential access medium and as a result, response times for reading the tape can be slow. There can be further delay is the tape is not already mounted.

If the delay is too long, the IBM Tivoli Storage Manager server cancels the request and sends an exception to the Content Platform Engine, which prompts you to retry the retrieval later.

Concurrent tape readers

The Concurrent Tape Readers configuration parameter for the IBM Tivoli Storage Manager fixed content device limits the number of users that can be waiting for a tape to be mounted. The configuration parameter represents the maximum number of concurrent users that are allowed to wait for a tape to be mounted for each Content Platform Engine instance, for each IBM Tivoli Storage Manager fixed content device. If the maximum number of users is already waiting for a tape to be mounted, new requests that require a tape to be mounted are denied. The Content Platform Engine does not limit the number of users that can read from tape, it limits the number of users that can wait for the tape to be mounted.

If your tape library contains multiple tape drives, the minimum value for the Concurrent Tape Readers parameter is the number of drives in the library. You can also increase the Concurrent Tape Readers parameter if the tape is either normally already mounted (that is, you have a small number of tapes) or if the tape can be mounted quickly. Depending on how your data is organized on the tape and the performance of your tape library, you can increase the value of this parameter, especially if you get a high number of retrieval failures for documents on tape and you believe that your tape library can handle more of these requests.

Each waiting user takes up one IBM Tivoli Storage Manager session and one item in the fixed content provider pool. You can adjust the IBM Tivoli Storage Manager MAXSESSIONS parameter and the Content Platform Engine FCP Pool Max In Use parameter to account for users who are waiting for a tape to be mounted.

When you set the Concurrent Tape Readers parameter, follow these guidelines:
  • The Concurrent Tape Readers parameter must be lower than the IBM Tivoli Storage Manager MAXSESSIONS parameter to allow other users to access the IBM Tivoli Storage Manager device.
  • If the Concurrent Tape Readers parameter is set too low, many users might receive unnecessary failure messages when attempting to read from tape.
  • If the Concurrent Tape Readers parameter is set too high, a large number of users might be queued up waiting for tape, consuming all sessions. If sessions are not available, other users cannot read from and new content cannot be migrated to the IBM Tivoli Storage Manager.

Timeout parameters

When you retrieve content that is stored on an IBM Tivoli Storage Manager server, the Content Platform Engine first attempts to obtain the content without waiting for a tape to be mounted. If the content is not stored on tape, it is retrieved and returned to you immediately. If the content is stored on tape, the Content Platform Engine determines whether you can wait for the tape to be mounted, based on the number of concurrent tape readers and the current number of waiting users.

If the number of users that are already waiting is equal to or greater than the number of concurrent tape readers, the Content Platform Engine produces an exception that rejects the read request and asks you to retry the retrieval at a later time. If you are allowed to wait, the Content Platform Engine tries to obtain the content. In this case, the tape is either mounted successfully and the content is returned to you, or the mount request times out.

Disk storage pool

For optimum performance, you can configure the IBM Tivoli Storage Manager server with a disk storage pool in front of the storage pool that is used for tape. Specify a migration policy to migrate items from the disk pool to the tape pool, as required. Configure the IBM Tivoli Storage Manager client node that is used by your fixed content device to use this disk pool as its primary storage pool.

Without a disk storage pool, you risk running out of storage space in the Content Platform Engine staging area of the IBM Tivoli Storage Manager fixed storage area during periods of high content ingestion. Because FileNet® P8 objects are staged locally in the IBM Tivoli Storage Manager fixed storage area before being queued up for migration to the IBM Tivoli Storage Manager server, FileNet P8 must provide enough local storage to accommodate the accumulation of documents before migration. Writing data directly to a sequential storage device such as a tape drive represents a slower migration. Consequently, this process requires a larger storage space requirement in the staging area and a larger the migration queue in the Content Platform Engine object store.

To maximize ingestion performance while ensuring that documents can be transferred fast enough from the staging area before hitting quota limits, configuring Content Platform Engine to write to a disk storage pool is preferable to writing directly to tape.

You can increase your migration rates by expanding your system as follows:
  • Increase the number of migration threads against the IBM Tivoli Storage Manager server.
  • Create multiple IBM Tivoli Storage Manager fixed storage areas that migrate into the same physical IBM Tivoli Storage Manager server.
  • Install multiple Content Platform Engine instances, each with multiple migration queues and a high number of threads, that feed into the same IBM Tivoli Storage Manager system.

Content cache

Using a content cache greatly improves retrieval performance. If the content that is stored on tape will be read multiple times, the content cache copies the content from the IBM Tivoli Storage Manager tape to a shared file system (content cache area) on the first retrieval, and all subsequent retrievals read the content from the file system until the content is aged out of the cache.

The content cache has its own inherent timeout mechanism. If a retrieval from tape times out, the content cache returns a message that instructs you to try your retrieval again later. In the meantime, the content cache continues to try to retrieve the tape content so that the content is available in its cache area the next time you make your retrieval request.

When you create a content cache, increase the Maximum Size and Maximum Number of Elements parameters for your cache area as the default values for these settings are typically too small. After the content cache is created, make sure that you select it in the content cache tab of your site properties. When specifying a content cache for a site, you must select the Override inherited setting check box. Then you can select the cache area to use for your site. See Content cache areas for more details.

The fixed storage areas in the object store that you have associated to IBM Tivoli Storage Manager fixed content devices must be set to value set for the Content Caching Allowed parameter, instead of the Cross-site Only parameter. This setting allows tape content to be cached for your site while it is being retrieved from the IBM Tivoli Storage Manager server.



Last updated: March 2016
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