IBM AS/400e User Handbook Manual page 493

• Expert Cache
Expert Cache provides a disk cache tuner option, which allows the AS/400 system to take
advantage of available main storage capacity. It dynamically responds to system jobs to
cache pages of data in main storage to reduce the time to process disk I/O.
• Integrated Hardware Disk Compression
Beginning with OS/400, V4R3 compression of data on disk is supported by OS/400. Data
is dynamically compressed and uncompressed by the DASD controller as data is written
to and read from disk. Disk compression does not effect the main CPU utilization since
this function is performed by the DASD controller IOP.
Support for Integrated Hardware Disk Compression is provided by #2741, #2748,
#4748/#9748 PCI DASD controllers, #6533 and #9754 SPD DASD controllers, and the
#9754 MFIOP with RAID adapter. Compression is limited to the fifteen user ASPs.
The resulting compression ratio varies, with most data compressing at a 20 to 40%
reduction. The compression rates achieved and the subsequent impact on DASD
performance depends on the data.
• Hierarchical Storage Management
OS/400 includes Hierarchical Storage Management (HSM) APIs used by Backup and
Recovery Media Services (BRMS), 5769-BR1, to provide HSM functions. These APIs can
also be used to develop custom HSM applications. The APIs are documented in AS/400
Hierarchical Storage Management , SC41-4450. Refer to the following Web site for more
information on BRMS and HSM:
• Internet PTFs
AS/400 customers can download PTFs over the Internet. The client hardware needed is a
PC with Windows 95 or Windows NT, a TCP connection to the AS/400 system over a
LAN, and access to the Internet. Selected configurations and set up information is
documented on the Web at:
Except for the medium of transport, the functionality of PTF download over the Internet is
the same as the ECS method of transport. The user selects the PTFs and options using a
Web browser and submits the order. At the AS/400 service Web site, the user can also
search for and read PTF cover letters before the order is placed. The same entitlement
rules that apply on the ECS connection are enforced. In other words, if a user can acquire
PTFs electronically with ECS, they can acquire PTFs over the Internet.
• System availability
Various functions are available to help maintain the availability of an AS/400 system.
These include:
– AS/400 systems support an optional Uninterruptable Power Supply (UPS) to maintain
power to the AS/400 system during a site power loss.
http://www.as400.ibm.com/hsmcomp
http://as400service.rochester.ibm.com
Operating System/400, 5769-SS1
Operating System/400, 5769-SS1
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