path: root/HOWTO
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authorJens Axboe <>2009-02-19 21:32:12 +0100
committerJens Axboe <>2009-02-19 21:32:12 +0100
commit8347239af0a361e160293100bfc053f88bbbf737 (patch)
tree79640f7bbcdecc1b27bf5a5eb411e80be4cdd6f0 /HOWTO
parent112b52d9033015ce46506fd05c67c6a537024c59 (diff)
Allow 'norandommap' with verify
We used to turn off verify completely if norandommap was given, since fio does not track block rewrites. But we can easily track rewrites, as long as we don't have to track various extent sizes. So relax the restriction to only cover norandommap with differing block sizes and adapt log_io_piece() to always use rbtree inserts for cases where we do need to check for potential overwrites. Signed-off-by: Jens Axboe <>
Diffstat (limited to 'HOWTO')
1 files changed, 3 insertions, 3 deletions
diff --git a/HOWTO b/HOWTO
index f256f24f..4ff2d929 100644
--- a/HOWTO
+++ b/HOWTO
@@ -532,9 +532,9 @@ norandommap Normally fio will cover every block of the file when doing
new random offset without looking at past io history. This
means that some blocks may not be read or written, and that
some blocks may be read/written more than once. This option
- is mutually exclusive with verify= for that reason, since
- fio doesn't track potential block rewrites which may alter
- the calculated checksum for that block.
+ is mutually exclusive with verify= if and only if multiple
+ blocksizes (via bsrange=) are used, since fio only tracks
+ complete rewrites of blocks.
softrandommap See norandommap. If fio runs with the random block map enabled
and it fails to allocate the map, if this option is set it