projects / unix-history / blame
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1 | .\" Copyright (c) 1991, 1993 |
| 2 | .\" The Regents of the University of California. All rights reserved. | |
| 1f137805 | 3 | .\" |
| d4fc960b | 4 | .\" %sccs.include.redist.roff% |
| b42074ab | 5 | .\" |
| 653ba8b6 | 6 | .\" @(#)update.8 8.2 (Berkeley) %G% |
| b42074ab CL |
7 | .\" |
| 8 | .Dd | |
| 9 | .Dt UPDATE 8 | |
| f0e10839 | 10 | .Os |
| b42074ab CL |
11 | .Sh NAME |
| 12 | .Nm update | |
| 13 | .Nd flush internal filesystem caches to disk frequently | |
| 14 | .Sh SYNOPSIS | |
| 15 | .Nm update | |
| 16 | .Sh DESCRIPTION | |
| 17 | The | |
| 18 | .Nm update | |
| 19 | command helps protect the integrity of disk volumes | |
| 20 | by flushing | |
| 653ba8b6 | 21 | volatile cached filesystem data |
| b42074ab CL |
22 | to disk at thirty second intervals. |
| 23 | .Nm Update | |
| 24 | uses the | |
| 25 | .Xr sync 2 | |
| 26 | function call to do the task. | |
| 27 | .Pp | |
| 28 | .Nm Update | |
| 29 | is commonly invoked at startup time by | |
| 30 | .Xr rc 8 | |
| 31 | when the system goes multi-user. | |
| 32 | .Sh SEE ALSO | |
| 33 | .Xr sync 2 , | |
| 34 | .Xr fsck 8 , | |
| 35 | .Xr init 8 , | |
| 36 | .Xr rc 8 , | |
| 37 | .Xr sync 8 | |
| 38 | .Sh BUGS | |
| 653ba8b6 | 39 | It is possible on some systems that a |
| 124881cc | 40 | .Xr sync |
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41 | occuring simultaneously with a crash may cause |
| 42 | file system damage. See | |
| 43 | .Xr fsck 8 . | |
| 44 | .Sh HISTORY | |
| 45 | An | |
| d4fc960b | 46 | .Nm update |
| f0e10839 | 47 | command appeared in |
| d4fc960b | 48 | .At v6 . |