As we changed to add a 5% summary cache some time ago, we should also change default read to DIRECTIO.
That was an oversight at the time.
@@ -292,7 +292,7 @@ summary.write.io enum {NORMAL, OSYNC, DIRECTIO} default=DIRECTIO
## Control io options during read of stored documents.
## All summary.read options will take effect immediately on new files written.
## On old files it will take effect either upon compact or on restart.
-summary.read.io enum {NORMAL, DIRECTIO, MMAP } default=MMAP restart
+summary.read.io enum {NORMAL, DIRECTIO, MMAP } default=DIRECTIO restart
## Multiple optional options for use with mmap
summary.read.mmap.options[] enum {MLOCK, POPULATE, HUGETLB} restart
