Filebench - A Model Based File System Workload Generator ======================================================== * Usage filebench binary allows to run individual workload personalities. Below is an example of individual varmail workload run: shell# filebench filebench> load varmail 8395: 3.898: Varmail personality successfully loaded 8395: 3.899: Usage: set $dir=<dir> 8395: 3.900: set $filesize=<size> defaults to 16384 8395: 3.900: set $nfiles=<value> defaults to 1000 8395: 3.901: set $dirwidth=<value> defaults to 20 8395: 3.901: set $nthreads=<value> defaults to 1 8395: 3.902: set $meaniosize=<value> defaults to 16384 8395: 3.902: run <runtime> filebench> set $dir=/tmp filebench> run 10 8395: 14.886: Fileset mailset: 1000 files, avg dir = 20, avg depth = 2.305865, mbytes=15 8395: 15.301: Preallocated fileset mailset in 1 seconds 8395: 15.301: Starting 1 filereader instances 8396: 16.313: Starting 1 filereaderthread threads 8395: 19.323: Running for 10 seconds... 8395: 29.333: Stats period = 10s 8395: 29.347: IO Summary: 21272 iops 2126.0 iops/s, (1063/1063 r/w) 32.1mb/s, 338us cpu/op, 0.3ms latency 8395: 29.348: Shutting down processes filebench> quit * Peculiarities If you get an ENOMEM error on pthread_create() and you use a thread model, there is a chance that Filebench runs out of virtual memory. E.g., under OLTP workload we have more than 400 threads (200 processes, each has 2 threads, where one thread is a control thread). By default NPTL mmaps current stack ulimit bytes for each thread, which is 8MB by default on Linux. So, in total this process uses 400 \* 8MB = 3.2G, which is more than a process can address on Linux. One workaround is to set stack ulimit to unlimited, which will cause NPTL to use only 2MB of mmaped memory for each thread. Notice, that you need to set ulimit in the shell, which invokes the executable. It won't help you doing it in the main() function, because NTPL reads the ulimits before main() is invoked. * New features added to this port You can define position sets: define posset name=myposset,entries=50,type=rnd,max=7516192768,seed=2 This will create a possition set of 50 entries. Each position will be generated using rand() function with seed 2 and will be in the range [0 - 7516192768]. We round every generated position to 512 at the moment. After position set is defined, it can be attributed to a read or write flowop: flowop write name=myfop,filesetname=myfst,possetname=myposset,random,iosize=2k In this case, every write will happen at the position randomly selected from the position set. Important to notice, that both possetname and random attributes must be specified. If only possetname is specified, it is ignored. ===========================================================
