SCF Reference Manual for G-Series RVUs (G06.27+)

SCF Commands
SCF Reference Manual for G-Series RVUs—520413-005
5-127
TRACE Command
BULKIO | NOBULKIO
designates whether TRACE should use bulk I/O for tracing. BULKIO (the default)
specifies that the TRACE collector use bulk I/O to write data to the file, thus
reducing the number of missing frame errors reported by PTrace.
A limitation of bulk I/O is that only one user can access the file at a time. If shared
access of the trace file is needed while the trace is active, you must specify
NOBULKIO. Bulk I/O tracing is faster and eliminates most data loss. You cannot
use BULKIO with NOCOLL. You cannot change this attribute during a trace.
COUNT count
specifies the number of trace records to be captured. The count variable is an
integer in the range -1 through 32767. If COUNT is omitted or if count equals -1,
records are accumulated until the trace is stopped, or until the end-of-file is
reached if the WRAP option (described below) is not selected.
NOPREALLOCATE | PREALLOCATE
specifies whether the maximum number of file extents (16) and associated disk
space are set aside at the start of the TRACE operation. PREALLOCATE is the
default action.
If NOPREALLOCATE is specified, file extents are allocated to the TRACE
operation one-by-one, as required, up to the maximum of 16. Use this option if
disk space is limited and the extra time required for segment-by-segment allocation
is an acceptable tradeoff.
RECSIZE size
specifies the length of the data in the trace data records. The size variable is an
integer in the range 16 through 4050 or is equal to 0 (zero). The length of the trace
header, which is 8 bytes, is not included in size. If RECSIZE is omitted or if size
equals 0, the default value of 120 bytes is assumed.
SELECT select-spec
The select-spec variable is one of the following specifications:
{ keyword }
{ ( keyword [ , keyword ]… ) }
{ number }
{ ( number [ , number ]… ) }
keyword
is subsystem-specific.
number
is the numeric value that a keyword represents.