| tunefs.8 (97478) | tunefs.8 (98542) |
|---|---|
| 1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 16 unchanged lines hidden (view full) --- 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)tunefs.8 8.2 (Berkeley) 12/11/93 | 1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 16 unchanged lines hidden (view full) --- 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)tunefs.8 8.2 (Berkeley) 12/11/93 |
| 33.\" $FreeBSD: head/sbin/tunefs/tunefs.8 97478 2002-05-29 16:55:50Z ru $ | 33.\" $FreeBSD: head/sbin/tunefs/tunefs.8 98542 2002-06-21 06:18:05Z mckusick $ |
| 34.\" | 34.\" |
| 35.Dd December 11, 1993 | 35.Dd May 18, 2002 |
| 36.Dt TUNEFS 8 37.Os 38.Sh NAME 39.Nm tunefs 40.Nd tune up an existing filesystem 41.Sh SYNOPSIS 42.Nm 43.Op Fl A 44.Op Fl a Ar maxcontig | 36.Dt TUNEFS 8 37.Os 38.Sh NAME 39.Nm tunefs 40.Nd tune up an existing filesystem 41.Sh SYNOPSIS 42.Nm 43.Op Fl A 44.Op Fl a Ar maxcontig |
| 45.Op Fl d Ar rotdelay | |
| 46.Op Fl e Ar maxbpg 47.Op Fl f Ar avgfilesize 48.Op Fl m Ar minfree 49.Bk -words 50.Op Fl n Ar enable | disable 51.Op Fl o Ar space | time 52.Op Fl p 53.Op Fl s Ar avgfpdir 54.Ek 55.Ar special | Ar filesystem 56.Sh DESCRIPTION 57.Nm Tunefs 58is designed to change the dynamic parameters of a filesystem 59which affect the layout policies. | 45.Op Fl e Ar maxbpg 46.Op Fl f Ar avgfilesize 47.Op Fl m Ar minfree 48.Bk -words 49.Op Fl n Ar enable | disable 50.Op Fl o Ar space | time 51.Op Fl p 52.Op Fl s Ar avgfpdir 53.Ek 54.Ar special | Ar filesystem 55.Sh DESCRIPTION 56.Nm Tunefs 57is designed to change the dynamic parameters of a filesystem 58which affect the layout policies. |
| 59The 60.Nm 61program cannot be run on an active filesystem. 62To change an active filesystem, 63you must either downgrade the filesystem to read-only 64or unmount it. 65.Pp |
|
| 60The parameters which are to be changed are indicated by the flags 61given below: 62.Bl -tag -width indent 63.It Fl A 64The filesystem has several backups of the super-block. Specifying 65this option will cause all backups to be modified as well as the 66primary super-block. This is potentially dangerous - use with caution. 67.It Fl a Ar maxcontig 68Specify the maximum number of contiguous blocks that will | 66The parameters which are to be changed are indicated by the flags 67given below: 68.Bl -tag -width indent 69.It Fl A 70The filesystem has several backups of the super-block. Specifying 71this option will cause all backups to be modified as well as the 72primary super-block. This is potentially dangerous - use with caution. 73.It Fl a Ar maxcontig 74Specify the maximum number of contiguous blocks that will |
| 69be laid out before forcing a rotational delay (see 70.Fl d 71below). 72The default value is one, since most device drivers require 73an interrupt per disk transfer. 74Device drivers that can chain several buffers together in a single 75transfer should set this to the maximum chain length. 76.It Fl d Ar rotdelay 77Specify the expected time (in milliseconds) 78to service a transfer completion 79interrupt and initiate a new transfer on the same disk. 80It is used to decide how much rotational spacing to place between 81successive blocks in a file. | 75be laid out before allowing a rotational delay. 76The default value is 16. |
| 82.It Fl e Ar maxbpg 83Indicate the maximum number of blocks any single file can 84allocate out of a cylinder group before it is forced to begin 85allocating blocks from another cylinder group. 86Typically this value is set to about one quarter of the total blocks 87in a cylinder group. 88The intent is to prevent any single file from using up all the 89blocks in a single cylinder group, --- 36 unchanged lines hidden (view full) --- 126fragmentation on the disk. 127Optimization for space has much 128higher overhead for file writes. 129The kernel normally changes the preference automatically as 130the percent fragmentation changes on the filesystem. 131.It Fl p 132Show a summary of what the current tunable settings 133are on the selected filesystem. More detailed information can be | 77.It Fl e Ar maxbpg 78Indicate the maximum number of blocks any single file can 79allocate out of a cylinder group before it is forced to begin 80allocating blocks from another cylinder group. 81Typically this value is set to about one quarter of the total blocks 82in a cylinder group. 83The intent is to prevent any single file from using up all the 84blocks in a single cylinder group, --- 36 unchanged lines hidden (view full) --- 121fragmentation on the disk. 122Optimization for space has much 123higher overhead for file writes. 124The kernel normally changes the preference automatically as 125the percent fragmentation changes on the filesystem. 126.It Fl p 127Show a summary of what the current tunable settings 128are on the selected filesystem. More detailed information can be |
| 134obtained in the | 129obtained from the |
| 135.Xr dumpfs 8 | 130.Xr dumpfs 8 |
| 136manual page. | 131or 132.Xr ffsinfo 8 133programs. |
| 137.It Fl s Ar avgfpdir 138Specify the expected number of files per directory. 139.El 140.Pp 141At least one of the above flags is required. 142.Sh FILES 143.Bl -tag -width ".Pa /etc/fstab" 144.It Pa /etc/fstab 145read this to determine the device file for a 146specified mount point. 147.El 148.Sh SEE ALSO 149.Xr fs 5 , 150.Xr dumpfs 8 , | 134.It Fl s Ar avgfpdir 135Specify the expected number of files per directory. 136.El 137.Pp 138At least one of the above flags is required. 139.Sh FILES 140.Bl -tag -width ".Pa /etc/fstab" 141.It Pa /etc/fstab 142read this to determine the device file for a 143specified mount point. 144.El 145.Sh SEE ALSO 146.Xr fs 5 , 147.Xr dumpfs 8 , |
| 148.Xr ffsinfo 8 , |
|
| 151.Xr newfs 8 152.Rs 153.%A M. McKusick 154.%A W. Joy 155.%A S. Leffler 156.%A R. Fabry 157.%T "A Fast File System for UNIX" 158.%J "ACM Transactions on Computer Systems 2" 159.%N 3 160.%P pp 181-197 161.%D August 1984 162.%O "(reprinted in the BSD System Manager's Manual, SMM:5)" 163.Re 164.Sh BUGS | 149.Xr newfs 8 150.Rs 151.%A M. McKusick 152.%A W. Joy 153.%A S. Leffler 154.%A R. Fabry 155.%T "A Fast File System for UNIX" 156.%J "ACM Transactions on Computer Systems 2" 157.%N 3 158.%P pp 181-197 159.%D August 1984 160.%O "(reprinted in the BSD System Manager's Manual, SMM:5)" 161.Re 162.Sh BUGS |
| 165This program should work on mounted and active filesystems. 166Because the super-block is not kept in the buffer cache, 167the changes will only take effect if the program 168is run on dismounted filesystems. 169To change the root filesystem, the system must be rebooted 170after the filesystem is tuned. 171.\" Take this out and a Unix Demon will dog your steps from now until | 163This program should work on active filesystems. 164.\" Take this out and a Unix Daemon will dog your steps from now until |
| 172.\" the time_t's wrap around. 173.Pp 174You can tune a filesystem, but you can't tune a fish. 175.Sh HISTORY 176The 177.Nm 178command appeared in 179.Bx 4.2 . | 165.\" the time_t's wrap around. 166.Pp 167You can tune a filesystem, but you can't tune a fish. 168.Sh HISTORY 169The 170.Nm 171command appeared in 172.Bx 4.2 . |