HP BA322 90087 - Manual (Page 233)

!
! Note:
! The LAD disk block cache is structured as a number of fixed-size
! buckets. You must specify both the bucket size and the number of
! buckets for the cache.
!
! The LAD cache is allocated from non-paged pool and is in no way
! associated with the XFC cache. The total LAD cache size in bytes
! may be determined by the formula:
!
! cache-bytes = bucket-size-in-blocks * number-of-buckets * 512
!
! Be sure the SYSGEN parameters NPAGDYN/NPAGEVIR are sized appropriately.
!
! The following keywords with values are accepted by this procedure:
!
! BUFFER_SIZE - A number between 3 and 8 denoting the
! bucket size in blocks as follows:
! 3 - 8 blocks
! 4 - 16 blocks
! 5 - 32 blocks
! 6 - 64 blocks
! 7 - 128 blocks
! 8 - 256 blocks
! CACHE_BUCKETS - Number of buckets
! MAXIMUM_SERVICES - Maximum number of services (max=1024)
! WRITE_LIMIT - Server wide count of asynchronous writes
!--
BUFFER_SIZE = 3 ! default (8 block buckets)
CACHE_BUCKETS = 512 ! Default setting
WRITE_LIMIT = 0 ! No async writes
MAXIMUM_SERVICES = 256 ! default (typically more than enough)
The following table provides a short description of each of the parameters:
Description Parameter
The InfoServer block cache is structured as an array of fixed-size buffers (also called
buckets). The BUFFER_SIZE parameter determines the size of each buffer or bucket.
The numeric value of this parameter is an integer in the range 3 through 8,
representing the bucket size in 512-byte blocks as follows. Bucket sizes larger than
32 blocks might not be appropriate for most users. The OpenVMS client segments
I/O requests larger than 31 blocks into 31-block chunks, which could result in
excessive I/O activity to the disk. The cache is allocated from nonpaged pool and
is dedicated solely to the LAD driver. BUFFER_SIZE
8 blocks (default) 3
16 blocks 4
32 blocks 5
64 blocks 6
128 blocks 7
256 blocks 8
Determines the number of buckets in the cache. The default is 512. Numbers larger
than 16384 might adversely affect performance. To reach a desirable cache size,
consider increasing the BUFFER_SIZE parameter. CACHE_BUCKETS
Sets the maximum number of services that can be defined at one time for the server.
The value of this parameter must be a power of 2. The default and minimum value
is 256 (adequate for most circumstances); the maximum value is 1024. Each service
descriptor consumes nonpaged pool; however, unused services consume 4 bytes
each. MAXIMUM_SERVICES
The number of asynchronous write operations that can be outstanding for the
server at any time. The default is 0 (no outstanding asynchronous write operations). WRITE_LIMIT
C.3 Setting Up the InfoServer Server 233