IBM SG24-4576-00 - Manual (Page 188)

5.3.1 Disk Subsystem
The file server disk subsystem contains the files which are accessed by the LAN
workstations. The efficiency at which access is performed is directly related to
the file server performance. The following section describes some of the
findings of the IBM PC Server performance laboratory on the major factors that
affect hard disk subsystem performance.
5.3.1.1 Block Size and Cache Buffer Size (NetWare 3.12)
NetWare V3.12 allows you to set the cache buffer size in system memory and the
block size on the physical hard disk. Matching these values can help balance
the workload of the CPU and the DASD subsystem, thereby yielding an overall
higher throughput. It also improves file read/write retrieval time for a user on a
LAN workstation.
Block Size: The volume block size can be set when the volume is created using
the INSTALL.NLM facility.
D e f a u l t = 4 K B
Range = 4KB, 8KB, 16KB, 32KB and 64KB (NetWare 3.12)
Cache Buffer Size: The cache buffer size can be set in the STARTUP.NCF file
using the following format:
SET CACHE BUFFER SIZE=VALUE
Default value = 4KB
Range = 4KB - 16KB (NetWare 3.12)
Recommendation: Set the block size to 8192 (8KB). The cache buffer size
should be set to 8192 bytes also. These two values are closely related and
complement each other with respect to performance. Matching their size helps
to match buffer-to-buffer data transfers between disk and disk controller and
NetWare file cache in system memory.
In some cases, the adjusting of the block size parameter to match the cache
buffer size might not be as important as other considerations for the setting of
the block size. For example, a 64KB volume block size might be needed for
installing a multimedia application. This would be more important to users
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overall performance than would the matching of the block size to the cache
buffer size.
In the absence of these kind of requirements, use the values in the following
table to relate volume block size to cache buffer size.
Table 17. Volume Block Size and Cache Buffer Size Recommendations
Volume Block Size in KB Cache Buffer Size in bytes
4 4096
8 8192
16 16384
32 16384
64 16384
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NetWare Integration Guide