Use disk volumes to specify where you want to store Essbase index files (essn.ind) and data files (essn.pag).
Files are written to the disk volume in the following directory structure:
.../app/app_name/db_name
If you do not use the disk volumes setting, Essbase stores data only on the volume where the ARBORPATH directory resides. If the ARBORPATH variable is not set, Essbase stores data only on the volume where the server was started.
For new files, changes to the disk volumes setting take effect when you next start the database. Existing files and volumes are not affected.
For information about how to check the size of the index and data files, see Checking Index and Data File Sizes. |
You can specify disk volumes using Administration Services, MaxL, or ESSCMD. When you use disk volumes, Essbase provides the following options for each disk volume:
Maximum space to use on the volume (called Partition Size in Administration Services and Volume Size in ESSCMD)
You can specify index files, data files, or both. The default is index and data files on the same volume.
The default and recommended value is 2,097,152 KB (2 GB). When Essbase reaches the maximum file size, it creates a file and names it incrementally. For example, when ess00001.ind is filled to maximum size, Essbase creates ess00002.ind.
Essbase creates data files and index files in these situations:
If the total sizes of all files reach the maximum size that you specified in the disk volumes setting
By default, the total is the sum of all index and data file sizes. If you specify Index as the file type, the total refers to the sum of all index files on a volume. If you specify Data as the file type, the total refers to the sum of all data files on a volume.
For example, suppose you want to use up to 12 GB for Essbase files on volume E, 16 GB on volume F, and 16 GB on volume G. Essbase creates a file on volume F when, on volume E, the sizes of the index and data files reach 12 GB and more data needs to be written to disk.
If the size of an individual index or data file on any volume reaches 2 GB
Using the previous example (12 GB for volume E; 16 GB for volume F; and 16 GB for volume G), suppose volumes E and F have reached their capacities and Essbase is using volume G. On volume G, Essbase creates ess00001.ind, filling it to the default limit of 2 GB, and creates ess00001.pag, filling it to 1 GB. 3 GB of the 16 GB on volume G have been used. Because ess00001.ind has reached the maximum file size of 2 GB, the next time Essbase needs storage space when writing index files to disk, it creates ess00002.ind. When ess00002.ind reaches the 2 GB limit, Essbase creates ess00003.ind. Essbase follows the same procedures for data files.
Essbase names files consecutively, starting with ess00001.xxx, where xxx is ind for an index file and pag for a data file, and continuing up to ess65535.xxx. This naming convention applies to each volume, so in the above example, volumes E, F, and G each have files named ess00001.pag and ess00001.ind.
Keep in mind the following guidelines when specifying disk volumes:
Specify the disk volumes in the order in which you want the volumes to be used. You do not need to specify the volume on which Essbase is installed as one of the volumes; you can install on one volume and store data on other volumes.
If a volume reaches capacity, Essbase moves to the next volume.
If all specified volumes reach capacity, Essbase stops ongoing database operations, issues an error message, and performs fatal error handling. See Understanding Fatal Error Handling. If these events occur, shut down the database, allocate more disk space, and restart the database.
You can tell Essbase to stop storing files on a volume. Essbase can still access the volume as needed, but it no longer stores additional index and data information on the volume. To stop storing information on a volume, select the volume definition that you want to remove and click Delete.
You set disk volumes on a per-database basis. Multiple databases can use space on the same volume, so allocate space carefully. For example, if you specify 7 GB on Volume A for Database 1 and 7 GB on Volume A for Database 2, you have allocated 14 GB for Essbase files on Volume A.
On Windows, you can use Universal/Uniform Naming Convention (UNC) to specify a disk volume as the location of a network resource, such as a shared directory. Syntax:
\\ComputerName\SharedFolder\Resource