To troubleshoot some performance issues, we want to do some FS benchmark assessment using bonnie++, but whenever I try to execute, it only prints the usage without actually running. Can anyone please check and see if I missed anything obvious in the syntax?Current RAM for system - 516829 MOS - CentOS 6.8/usr/sbin/bonnie++ -r 516829  -d /opt -s 1033658 -n 1 -f -b -u root:rootIf I intentionally assign less value for -s, it promptly complains, e.g.     /usr/sbin/bonnie++ -r 516829  -d /opt -s 1033 -n 1 -f -b -u root:rootUsing uid:0, gid:0. File size should be double RAM for good results, RAM is 516829M.I have tried compiling bonnie++ from source as well as installing from yum but all showing same behavior.Drive for which we would like to measure I/O performance is /opt which is on a SAN mount.Thanks,~ Abhi
Unable to use bonnie++ for measuring I/O performance
benchmark
When this machine has 504 GB RAM it would need 1008 GB free space for the benchmark file and many many hours (maybe days) for the benchmarking process to complete./opt/ doesn't have enough diskspace thus you need to limit the ramsize and the filesize to something like this:# use only 16G of ram and 32G benchsize. bonnie++ -d /opt/ -r 16G -s 32G -n 1 -f -b -u rootJust in case I got it wrong and you've got 504 MB RAM (you wouldn't need the -r switch)bonnie++ -d /opt/ -s 1G -n 1 -f -b -u rootFrom the man pages - check the bold parts.-s the size of the file(s) for IO performance measures in megabytes. (..) The  chunk-size is measured in bytes and must be a power of two from 256 to  1048576, the default is 8192. NB You can specify the size in  giga-bytes or the chunk-size in kilo-bytes if you add g or k to the  end of the number respectively. If the specified size is 0 then this  test will be skipped.