Variable | Default | Functionality |
| Value |
|
|
|
|
HPSS_SM_SRV_MAX_CONNECTIONS |
| Number of HPSS server connections to |
|
| maintain at once. If this number of |
|
| connections is exceeded, then old |
|
| connections will be closed to maintain |
| 50 | this number of connections |
*The SM attempts to throttle the connection attempts to other servers. It will attempt to reconnect to each server every HPSS_SM_SRV_CONNECT_INTERVAL_MIN seconds until the number of failures for that server has reached HPSS_SM_SRV_CONNECT_FAIL_COUNT. After the failure count has been reached the SM will only try to reconnect to the server every HPSS_SM_SRV_CONNECT_INTERVAL_MAX seconds until a successful connection is made at which time the connection interval for the server will be set back to
HPSS_SM_SRV_CONNECT_INTERVAL_MIN.
3.8. Storage Subsystem Considerations
Storage subsystems are provided in HPSS for the purpose of increasing the scalability of the system, particularly with respect to the Core Servers. An HPSS system consists of one or more subsystems, and each subsystem contains its own Core Server. If multiple Core Servers are desired, this is accomplished by configuring multiple subsystems.
Each subsystem uses a separate DB2 database. Adding a subsystem to an HPSS system means adding an additional database that must be maintained and backed up.
3.9. Storage Policy Considerations
This section describes the various policies that control the operation of the HPSS system.
3.9.1. Migration Policy
The migration policy provides the capability for HPSS to copy (migrate) data from one level in a hierarchy to one or more lower levels. The migration policy defines the amount of data and the conditions under which it is migrated; however, the number of copies and the location of those copies is determined by the storage hierarchy definition. The site administrator will need to monitor the usage of the storage classes being migrated and adjust both the migration and purge policies to obtain the desired results.
3.9.1.1. Migration Policy for Disk
Disk migration in HPSS copies (migrates) files from a disk storage class to one or more lower levels in the storage hierarchy. Removing or purging of the files from disk storage class is controlled by the purge policy. The migration and purge policies work in conjunction to maintain sufficient storage space in the disk storage class.
When data is copied from the disk, the copied data will be marked purgeable but will not be deleted. Data is deleted by running purge on the storage class. If duplicate copies are created, the copied data is not marked purgeable until all copies have been successfully created. The migration policy and purge policy associated with a disk storage class must be set up to provide sufficient free space to deal with demand for storage. This involves setting the parameters in the migration policy to migrate a sufficient number of files and setting the purge policy to reclaim enough of this disk space to provide the free space desired for users of the disk storage class.
HPSS Installation Guide | July 2008 |
Release 6.2 (Revision 2.0) | 94 |
