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mdoc(7) police: Bump document date, removed (again) hard sentence breaks..

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Ruslan Ermilov 2002-08-13 14:37:41 +00:00
parent e316d2deba
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21
share/man/man7/tuning.7
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@ -4,7 +4,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd May 25, 2001
.Dd June 25, 2002
.Dt TUNING 7
.Os
.Sh NAME
@ -416,21 +416,28 @@ wasted memory but you should experiment to find out.
.Pp
The
.Va vfs.write_behind
sysctl defaults to 1 (on). This tells the filesystem to issue media
sysctl defaults to 1 (on).
This tells the filesystem to issue media
writes as full clusters are collected, which typically occurs when writing
large sequential files. The idea is to avoid saturating the buffer
cache with dirty buffers when it would not benefit I/O performance. However,
large sequential files.
The idea is to avoid saturating the buffer
cache with dirty buffers when it would not benefit I/O performance.
However,
this may stall processes and under certain circumstances you may wish to turn
it off.
.Pp
The
.Va vfs.hirunningspace
sysctl determines how much outstanding write I/O may be queued to
disk controllers system wide at any given instance. The default is
disk controllers system-wide at any given instance.
The default is
usually sufficient but on machines with lots of disks you may want to bump
it up to four or five megabytes. Note that setting too high a value
it up to four or five megabytes.
Note that setting too high a value
(exceeding the buffer cache's write threshold) can lead to extremely
bad clustering performance. Do not set this value arbitrarily high! Also,
bad clustering performance.
Do not set this value arbitrarily high!
Also,
higher write queueing values may add latency to reads occuring at the same
time.
.Pp