docs/163527: [patch] Update tuning(7) a bit

Garrett Cooper yanegomi at
Thu Dec 22 11:00:32 UTC 2011

>Number:         163527
>Category:       docs
>Synopsis:       [patch] Update tuning(7) a bit
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-doc
>State:          open
>Class:          doc-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Dec 22 11:00:25 UTC 2011
>Originator:     Garrett Cooper
>Release:        9.0-RC2
FreeBSD bayonetta.local 9.0-RC2 FreeBSD 9.0-RC2 #0: Sun Nov 13 21:17:31 PST 2011     gcooper at bayonetta.local:/usr/obj/store/freebsd/stable/9/sys/BAYONETTA  amd64
- Some of the defaults in tuning(7) haven't been updated following the changes made to the networking stack and UFS in 9.x .
- The manpage still references sysinstall.
- The manpage is lacking a suggestion to increase kern.ipc.nmbclusters, and in fact the recommended defaults are way too low for cxgb(4), igb(4), and a handful of other network cards (the default today on 8.x/9.x is 25600).

The attached patch improves upon those items.


Patch attached with submission follows:

Index: share/man/man7/tuning.7
--- share/man/man7/tuning.7	(revision 228662)
+++ share/man/man7/tuning.7	(working copy)
@@ -101,7 +101,9 @@
 depends on the kind of temporary file usage you think you will need.
 128M is
 the minimum we recommend.
-Also note that sysinstall will create a
+Also note that
+.Xr bsdinstall 8
+will create a
 .Pa /tmp
 Dedicating a partition for temporary file storage is important for
@@ -219,7 +221,7 @@
 performs best when using 8K or 16K file system block sizes.
-The default file system block size is 16K,
+The default file system block size is 32K,
 which provides best performance for most applications,
 with the exception of those that perform random access on large files
 (such as database server software).
@@ -286,7 +288,7 @@
 option to
 .Xr newfs 8 ,
-.Xr sysinstall 8
+.Xr bsdinstall 8
 will typically enable softupdates automatically for non-root file systems).
 Softupdates drastically improves meta-data performance, mainly file
 creation and deletion.
@@ -525,8 +527,8 @@
 to pre-read if the heuristics algorithm decides that the reads are
 issued sequentially.
 It is used by the UFS, ext2fs and msdosfs file systems.
-With the default UFS block size of 16 KiB, a setting of 32 will allow
-speculatively reading up to 512 KiB.
+With the default UFS block size of 32 KiB, a setting of 32 will allow
+speculatively reading up to 1 MiB.
 This setting may be increased to get around disk I/O latencies, especially
 where these latencies are large such as in virtual machine emulated
@@ -566,8 +568,8 @@
 They control the amount of send and receive buffer space
 allowed for any given TCP connection.
-The default sending buffer is 32K; the default receiving buffer
-is 64K.
+The default sending buffer is 128K; the default receiving buffer
+is 256K.
 You can often
 improve bandwidth utilization by increasing the default at the cost of
 eating up more kernel memory for each connection.
@@ -873,6 +875,15 @@
 Under no circumstances
 should you specify an arbitrarily high value for this parameter, it could
 lead to a boot-time crash.
+Please note that some drivers, require larger values, and in some cases the
+interfaces will hang on probe, e.g. dual-port (in some configurations) or
+.Xr igb 4 ,
+or cause system panics, e.g.
+.Xr cxgb 4 ,
+if you set
+.Va kern.ipc.nmbclusters
+to something less than 50000 and 75000, respectively.
 .Fl m
 option to
@@ -1041,6 +1052,7 @@
 .Xr hier 7 ,
 .Xr ports 7 ,
 .Xr boot 8 ,
+.Xr bsdinstall 8 ,
 .Xr bsdlabel 8 ,
 .Xr ccdconfig 8 ,
 .Xr config 8 ,
@@ -1055,7 +1067,6 @@
 .Xr newfs 8 ,
 .Xr route 8 ,
 .Xr sysctl 8 ,
-.Xr sysinstall 8 ,
 .Xr tunefs 8


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