X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=19304aefc87d92bc6fd17a3fd28f6768c79f8550;hp=7a7d14ea0816080d794d25f4d899603e2eee57a8;hb=ea3e51c36e09f9363c983de2ae123f983ee3f25c;hpb=a696fa2a9c2e21a1c88813235d6fc39d267f6155 diff --git a/HOWTO b/HOWTO index 7a7d14ea..19304aef 100644 --- a/HOWTO +++ b/HOWTO @@ -324,6 +324,11 @@ kb_base=int The base unit for a kilobyte. The defacto base is 2^10, 1024. randrepeat=bool For random IO workloads, seed the generator in a predictable way so that results are repeatable across repetitions. +fallocate=bool By default, fio will use fallocate() to advise the system + of the size of the file we are going to write. This can be + turned off with fallocate=0. May not be available on all + supported platforms. + fadvise_hint=bool By default, fio will use fadvise() to advise the kernel on what IO patterns it is likely to issue. Sometimes you want to test specific IO patterns without telling the @@ -561,8 +566,24 @@ fsync=int If writing to a file, issue a sync of the dirty data not sync the file. The exception is the sg io engine, which synchronizes the disk cache anyway. -fsyncdata=int Like fsync= but uses fdatasync() to only sync data and not +fdatasync=int Like fsync= but uses fdatasync() to only sync data and not metadata blocks. + In FreeBSD there is no fdatasync(), this falls back to + using fsync() + +sync_file_range=str:val Use sync_file_range() for every 'val' number of + write operations. Fio will track range of writes that + have happened since the last sync_file_range() call. 'str' + can currently be one or more of: + + wait_before SYNC_FILE_RANGE_WAIT_BEFORE + write SYNC_FILE_RANGE_WRITE + wait_after SYNC_FILE_RANGE_WAIT_AFTER + + So if you do sync_file_range=wait_before,write:8, fio would + use SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE for + every 8 writes. Also see the sync_file_range(2) man page. + This option is Linux specific. overwrite=bool If true, writes to a file will always overwrite existing data. If the file doesn't already exist, it will be @@ -921,7 +942,7 @@ read_iolog=str Open an iolog with the specified file name and replay the to replay a workload captured by blktrace. See blktrace for how to capture such logging data. For blktrace replay, the file needs to be turned into a blkparse binary data - file first (blktrace -d file_for_fio.bin). + file first (blkparse -o /dev/null -d file_for_fio.bin). write_bw_log=str If given, write a bandwidth log of the jobs in this job file. Can be used to store data of the bandwidth of the @@ -1004,22 +1025,28 @@ continue_on_error=bool Normally fio will exit the job on the first observed given in the stats is the first error that was hit during the run. -cgroup_root=str Root of the mounted blkio cgroup file systems. This is a Linux - specific IO controller. If your system doesn't have it mounted, - you can do so with: +cgroup=str Add job to this control group. If it doesn't exist, it will + be created. The system must have a mounted cgroup blkio + mount point for this to work. If your system doesn't have it + mounted, you can do so with: # mount -t cgroup -o blkio none /cgroup - The cgroup_root defaults to /cgroup, if mounted elsewhere - please specify this option. - -cgroup=str Add job to this control group. If it doesn't exist, it will - be created. - cgroup_weight=int Set the weight of the cgroup to this value. See the documentation that comes with the kernel, allowed values are in the range of 100..1000. +cgroup_nodelete=bool Normally fio will delete the cgroups it has created after + the job completion. To override this behavior and to leave + cgroups around after the job completion, set cgroup_nodelete=1. + This can be useful if one wants to inspect various cgroup + files after job completion. Default: false + +uid=int Instead of running as the invoking user, set the user ID to + this value before the thread/process does any work. + +gid=int Set group ID, see uid. + 6.0 Interpreting the output ---------------------------