TMF Reference Manual (G06.26+)

TMFCOM Commands
HP NonStop TMF Reference Manual—522418-003
3-104
ALTER PROCESS
You cannot manually adjust the segment size beyond 128 MB; the growth to the
1024-MB upper limit is managed entirely by TMF. You can determine the current
actual segment size by issuing the following command through NSKCOM, the
command interface for monitoring kernel-managed swap space:
STATUS SWAP-USAGE $TMP, DETAIL
For more information about NSKCOM, see Kernel-Managed Swap Facility (KMSF)
Manual.
EXTENDEDSEGSIZE Option Considerations for the
TMFMON
In addition to the considerations common to the TMP and TMFMON described under
EXTENDEDSEGSIZE Option Considerations on page 3-101, the TMFMON’s extended
segment has a relatively fixed component for various TMF Library tables and the
support of disk volumes attached to each CPU. Larger systems, of course, require
more space for these tables. The remainder of the segment involves TCBs and
message buffers in the TMF Library and other dynamic factors. TCB size depends on
the number of files involved in a given transaction and can differ greatly from processor
to processor, and message buffer use is very unpredictable.
Even though very precise estimates are difficult, a general operating guideline is
possible for the TMFMON. First, estimate the number of active transactions in your
system, as reflected by the TRANSCOUNTTHRESH value established by the ALTER
BEGINTRANS command. Next, consult the following table and enter the
corresponding EXTENDEDSEGSIZE value in the ALTER PROCESS command. Later,
if this value proves insufficient, you can raise it further.
TRANSCOUNTTHRESH EXTENDEDSEGSIZE
3000 10
3200 12
4000 16
5000 16
6000 18
7000 20
Note. The values in this table are based on the TRANSPERCPU default value, 1024, which
limits the number of transactions that can be active in a processor. Changing that value would
alter the fixed portion of the TMF library’s extended segment used. Therefore, if you increase
the TRANSPERCPU value, you should also increase the EXTENDEDSEGSIZE value.
Beyond the values shown in this table, assume that for every additional increase of 1000 in
TRANSCOUNTTHRESH, you should increase EXTENDEDSEGSIZE by 2 MB.