Lustre 1.6 Operations Manual

Parameter
--regioncount_low=RL
--regioncount_high=RH
--regioncount_inc=P
--regionnoise=k
--regionsize=S[,S2,S3...]
--regionsize_low=RL
--regionsize_high=RH
--regionsize_inc=P
--threadcount=T[,T2,T3...]
--threadcount_low=TL
--threadcount_high=TH
--threadcount_inc=TP
--threaddelay=ms
--fpp
--verify-V=timestamp
[,timestamp2,timestamp3]
|--verify|-V
Description
Generate runs with a range of region counts starting at TL,
increasing P% until the thread count exceeds RH. Each of
these arguments is exclusive with the regioncount argument.
When generating the next I/O task, do not select the next
chunk in the next stream, but shift a random number with a
maximum noise of shifting k regions ahead. The run will
complete when all regions are fully written or read. This
merely introduces a randomization of the ordering.
The argument is a byte specifier or a list of byte specifiers.
During the run(s), write S bytes to each region.
The arguments are byte specifiers. Generate runs with a range
of region sizes starting at TL, increasing P% until the region
size exceeds RH. Each argument is exclusive with the
regionsize argument.
PIOS runs with T threads performing I/O. A sequence of
values may be given.
Generate runs with a range of thread counts starting at TL,
increasing TP% until the thread count exceeds TH. Each of
these arguments is exclusive with the threadcount argument.
A random amount of noise not exceeding ms is inserted
between the time that a thread identifies as the next chunk it
needs to read or write and the time it starts the I/O.
Where threads write to files:
• fpp indicates files per process behavior where threads write
to multiple files.
• sff indicates single shared files where all threads write to
the same file.
Verify a written file or set of files. A single timestamp or
sequence of timestamps can be given for each run,
respectively. If no argument is passed, the verification is done
from timestamps read from the first location of files
previously written in the test. If sequence is given, then each
run verifies the timestamp accordingly. If a single timestamp
is given, then it is verified with all files written.
Chapter 19 Lustre I/O Kit 19-15