Update the default newfs block and fragment sizes from 8192/1024 to

16384/2048.

Following recent discussions on the -arch mailing list, involving dillon
and mckusick, this change parallels the one made over a decade ago when
the default was bumped up from 4096/512.

This should provide significant performance improvements for most
folks, less significant performance losses for a few folks and
wasted space lost to large fragments for many folks.

For discussion, please see the following thread in the -arch archive:

Subject: Using a larger block size on large filesystems

The discussion ceases to be relevant when the issue of partitioning
schemes is raised.

sbin/newfs/newfs.8

@@ -110,7 +110,7 @@ See
 for more details on how to set this option.
 .It Fl b Ar block-size
 The block size of the file system, in bytes.  It must be a power of 2.  The
-default size is 8192 bytes, and the smallest allowable size is 4096 bytes.
+default size is 16384 bytes, and the smallest allowable size is 4096 bytes.
 The optimal block:fragment ratio is 8:1.
 Other ratios are possible, but are not recommended,
 and may produce unpredictable results.
@@ -141,7 +141,7 @@ ranging in value between
 .Ar blocksize Ns /8
 and
 .Ar blocksize .
-The default is 1024 bytes.
+The default is 2048 bytes.
 .It Fl g Ar avgfilesize
 The expected average file size for the file system.
 .It Fl h Ar avgfpdir
@@ -271,15 +271,19 @@ This option is of historical importance only.  Modern disks perform their own
 bad sector allocation.
 .El
 .Sh EXAMPLES
-.Dl newfs -b 16384 -f 2048 /dev/ad3s1a
+.Dl newfs /dev/ad3s1a
 .Pp
 Creates a new ufs file system on
 .Pa ad3s1a .
 .Nm
 will use a block size of 16384 bytes, a fragment size of 2048 bytes
 and the largest possible number of cylinders per group.
-These values tend to produce better performance than the defaults
-for most applications.
+These values tend to produce better performance for most applications
+than the historical defaults
+(8192 byte block size and 1024 byte fragment size).
+This large fragment size
+may lead to large amounts of wasted space
+on filesystems that contain a large number of small files.
 .Sh SEE ALSO
 .Xr fdformat 1 ,
 .Xr disktab 5 ,

sbin/newfs/newfs.c

@@ -98,8 +98,8 @@ void	fatal();
  *	sectorsize <= DESFRAGSIZE <= DESBLKSIZE
  *	DESBLKSIZE / DESFRAGSIZE <= 8
  */
-#define	DFL_FRAGSIZE	1024
-#define	DFL_BLKSIZE	8192
+#define	DFL_FRAGSIZE	2048
+#define	DFL_BLKSIZE	16384
 
 /*
  * Cylinder groups may have up to many cylinders. The actual

share/man/man7/tuning.7

@@ -199,19 +199,29 @@ and
 .Pp
 .Fx
 performs best when using 8K or 16K filesystem block sizes.
-The default filesystem block size is 8K.
-For larger partitions it is usually a good
-idea to use a 16K block size.
-This also requires you to specify a larger
+The default filesystem block size is 16K,
+which provides best performance for most applications,
+with the exception of those that perform random access on large files
+(such as database server software).
+Such applications tend to perform better with a smaller block size,
+although modern disk characteristics are such that the performance
+gain from using a smaller block size may not be worth consideration.
+Using a block size larger than 16K
+can cause fragmentation of the buffer cache and
+lead to lower performance.
+.Pp
+The defaults may be unsuitable
+for a filesystem that requires a very large number of inodes
+or is intended to hold a large number of very small files.
+Such a filesystem should be created with an 8K or 4K block size.
+This also requires you to specify a smaller
 fragment size.
 We recommend always using a fragment size that is 1/8
 the block size (less testing has been done on other fragment size factors).
 The
 .Xr newfs 8
 options for this would be
-.Dq Li "newfs -f 2048 -b 16384 ..." .
-Using a larger block size can cause fragmentation of the buffer cache and
-lead to lower performance.
+.Dq Li "newfs -f 1024 -b 8192 ..." .
 .Pp
 If a large partition is intended to be used to hold fewer, larger files, such
 as a database files, you can increase the

usr.sbin/sade/install.c

@@ -1121,7 +1121,7 @@ installVarDefaults(dialogMenuItem *self)
 	variable_set2(SYSTEM_STATE,		"update", 0);
     else
 	variable_set2(SYSTEM_STATE,		"init", 0);
-    variable_set2(VAR_NEWFS_ARGS,		"-b 8192 -f 1024", 0);
+    variable_set2(VAR_NEWFS_ARGS,		"-b 16384 -f 2048", 0);
     variable_set2(VAR_CONSTERM,                 "NO", 0);
     return DITEM_SUCCESS;
 }

usr.sbin/sysinstall/install.c

@@ -1121,7 +1121,7 @@ installVarDefaults(dialogMenuItem *self)
 	variable_set2(SYSTEM_STATE,		"update", 0);
     else
 	variable_set2(SYSTEM_STATE,		"init", 0);
-    variable_set2(VAR_NEWFS_ARGS,		"-b 8192 -f 1024", 0);
+    variable_set2(VAR_NEWFS_ARGS,		"-b 16384 -f 2048", 0);
     variable_set2(VAR_CONSTERM,                 "NO", 0);
     return DITEM_SUCCESS;
 }