+++ /dev/null
-<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 3//EN">
-<HTML><HEAD>
-<TITLE>Administration Reference</TITLE>
-<!-- Begin Header Records ========================================== -->
-<!-- /tmp/idwt3190/auarf000.scr converted by idb2h R4.2 (359) ID -->
-<!-- Workbench Version (AIX) on 5 Nov 1999 at 13:58:29 -->
-<META HTTP-EQUIV="updated" CONTENT="Fri, 05 Nov 1999 13:58:29">
-<META HTTP-EQUIV="review" CONTENT="Sun, 05 Nov 2000 13:58:29">
-<META HTTP-EQUIV="expires" CONTENT="Mon, 05 Nov 2001 13:58:29">
-</HEAD><BODY>
-<!-- (C) IBM Corporation 2000. All Rights Reserved -->
-<BODY bgcolor="ffffff">
-<!-- End Header Records ============================================ -->
-<A NAME="Top_Of_Page"></A>
-<H1>Administration Reference</H1>
-<HR><P ALIGN="center"> <A HREF="../index.htm"><IMG SRC="../books.gif" BORDER="0" ALT="[Return to Library]"></A> <A HREF="auarf002.htm#ToC"><IMG SRC="../toc.gif" BORDER="0" ALT="[Contents]"></A> <A HREF="auarf163.htm"><IMG SRC="../prev.gif" BORDER="0" ALT="[Previous Topic]"></A> <A HREF="#Bot_Of_Page"><IMG SRC="../bot.gif" BORDER="0" ALT="[Bottom of Topic]"></A> <A HREF="auarf165.htm"><IMG SRC="../next.gif" BORDER="0" ALT="[Next Topic]"></A> <A HREF="auarf284.htm#HDRINDEX"><IMG SRC="../index.gif" BORDER="0" ALT="[Index]"></A> <P>
-<P>
-<H2><A NAME="HDRFS_STOREBEHIND" HREF="auarf002.htm#ToC_178">fs storebehind</A></H2>
-<A NAME="IDX4985"></A>
-<A NAME="IDX4986"></A>
-<P><STRONG>Purpose</STRONG>
-<P>Enables asynchronous writes to the file server
-<P><STRONG>Synopsis</STRONG>
-<PRE><B>fs storebehind</B> [<B>-kbytes</B> <<VAR>asynchrony for specified names</VAR>>]
- [<B>-files</B> <<VAR>specific pathnames</VAR>><SUP>+</SUP>]
- [<B>-allfiles</B> <<VAR>new default (KB)</VAR>>] [<B>-verbose</B>] [<B>-help</B>]
-
-<B>fs st</B> [<B>-k</B> <<VAR>asynchrony for specified names</VAR>>] [<B>-f</B> <<VAR>specific pathnames</VAR>><SUP>+</SUP>]
- [<B>-a</B> <<VAR>new default (KB)</VAR>>] [<B>-v</B>] [<B>-h</B>]
-</PRE>
-<P><STRONG>Description</STRONG>
-<P>The <B>fs storebehind</B> command enables the Cache Manager to perform
-a delayed asynchronous write to the File Server when an application closes a
-file. By default, the Cache Manager writes all data to the File Server
-immediately and synchronously when an application program closes a
-file--that is, the <B>close</B> system call does not return until the
-Cache Manager has actually transferred the final chunk of the file to the File
-Server. This command specifies the number of kilobytes of a file that
-can still remain to be written to the File Server when the Cache Manager
-returns control to the application. It is useful if users working on
-the machine commonly work with very large files, but also introduces the
-complications discussed in the <B>Cautions</B> section.
-<P>Set either or both of the following in a single command:
-<UL>
-<P><LI>To set a value that applies to all AFS files manipulated by applications
-running on the machine, use the <B>-allfiles</B> argument. This
-value is termed the <I>default store asynchrony</I> for the machine, and
-persists until the machine reboots. If it is not set, the default value
-is zero, indicating that the Cache Manager performs synchronous writes.
-<P>
-<P>As an example, the following setting means that when an application closes
-a file, the Cache Manager can return control to the application as soon as no
-more than 10 kilobytes of the file remain to be written to the File
-Server.
-<PRE> <B>-allfiles 10</B>
-
-</PRE>
-<P><LI>To set a value that applies to one or more individual files, and overrides
-the value of the <B>-allfiles</B> argument for them, combine the
-<B>-kbytes</B> and <B>-files</B> arguments. The setting
-persists as long as there is an entry for the file in the kernel table that
-the Cache Manager uses to track certain information about files. In
-general, such an entry persists at least until an application closes the file
-or exits, but the Cache Manager is free to recycle the entry if the file is
-inactive and it needs to free up slots in the table. To increase the
-certainty that there is an entry for the file in the table, issue the <B>fs
-storebehind</B> command shortly before closing the file.
-<P>As an example, the following setting means that when an application closes
-either of the files <B>bigfile</B> and <B>biggerfile</B>, the Cache
-Manager can return control to the application as soon as no more than a
-megabyte of the file remains to be written to the File Server.
-<PRE> <B>-kbytes 1024 -files bigfile biggerfile</B>
-
-</PRE>
-<P>Note that once an explicit value has been set for a file, the only way to
-make it subject to the default store asynchrony once again is to set
-<B>-kbytes</B> to that value. In other words, there is no
-combination of arguments that automatically makes a file subject to the
-default store asynchrony once another value has been set for the file.
-</UL>
-<P>To display the settings that currently apply to individual files or to all
-files, provide the command's arguments in certain combinations as
-specified in the <B>Output</B> section of this reference page.
-<P><STRONG>Cautions</STRONG>
-<P>For the following reasons, use of this command is not recommended in most
-cases.
-<P>In normal circumstances, an asynchronous setting results in the Cache
-Manager returning control to applications earlier than it otherwise does, but
-this is not guaranteed.
-<P>If a delayed write fails, there is no way to notify the application, since
-the <B>close</B> system call has already returned with a code indicating
-success.
-<P>Writing asynchronously increases the possibility that the user will not
-notice if a write operation makes the volume that houses the file exceed its
-quota. As always, the portion of the file that exceeds the
-volume's quota is lost, which prompts a message such as the
-following:
-<PRE> No space left on device
-
-</PRE>
-<P>To avoid losing data, it is advisable to verify that the volume housing the
-file has space available for the amount of data anticipated to be
-written.
-<P><STRONG>Options</STRONG>
-<DL>
-<P><DT><B>-kbytes
-</B><DD>Specifies the number of kilobytes of data from each file named by the
-<B>-files</B> argument that can remain to be written to the file server
-when the Cache Manager returns control to an application program that closed
-the file. The <B>-files</B> argument is required along with this
-argument. Provide an integer from the range <B>0</B> (which
-reinstates the Cache Manager's default behavior or writing synchronously)
-to the maximum AFS file size.
-<P><DT><B>-files
-</B><DD>Names each file to which the value set with the <B>-kbytes</B>
-argument applies. The setting persists as long as there is an entry for
-the file in the kernel table that the Cache Manager uses to track certain
-information about files. Because closing a file generally erases the
-entry, when reopening a file the only way to guarantee that the setting still
-applies is to reissue the command. If this argument is provided without
-the <B>-kbytes</B> argument, the command reports the current setting for
-the specified files, and the default store asynchrony.
-<P><DT><B>-allfiles
-</B><DD>Sets the default store asynchrony for the local machine, which is the
-number of kilobytes of data that can remain to be written to the file server
-when the Cache Manager returns control to the application program that closed
-a file. The value applies to all AFS files manipulated by applications
-running on the machine, except those for which settings have been made with
-the <B>-kbytes</B> and <B>-files</B> arguments. Provide an
-integer from the range <B>0</B> (which indicates the default of
-synchronous writes) to the maximum AFS file size.
-<P><DT><B>-verbose
-</B><DD>Produces output confirming the settings made with the accompanying
-<B>-kbytes</B> and <B>-files</B> arguments, the <B>-allfiles</B>
-argument, or all three. If provided by itself, reports the current
-default store asynchrony.
-<P><DT><B>-help
-</B><DD>Prints the online help for this command. All other valid options
-are ignored.
-</DL>
-<P><STRONG>Output</STRONG>
-<P>If none of the command's options are included, or if only the
-<B>-verbose</B> flag is included, the following message reports the
-default store asynchrony (the setting that applies to all files manipulated by
-applications running on the local machine and for which not more specific
-asynchrony is set).
-<PRE> Default store asynchrony is <VAR>x</VAR> kbytes.
-
-</PRE>
-<P>A value of <TT>0</TT> (zero) indicates synchronous writes and is the
-default if no one has included the <B>-allfiles</B> argument on this
-command since the machine last rebooted.
-<P>If the <B>-files</B> argument is provided without the
-<B>-kbytes</B> argument, the output reports the value that applies to each
-specified file along with the default store asynchrony. If a particular
-value has previously been set for a file, the following message reports
-it:
-<PRE> Will store up to <VAR>y</VAR> kbytes of <VAR>file</VAR> asynchronously.
- Default store asynchrony is <VAR>x</VAR> kbytes.
-
-</PRE>
-<P>If the default store asynchrony applies to a file because no explicit
-<B>-kbytes</B> value has been set for it, the message is instead as
-follows:
-<PRE> Will store <VAR>file</VAR> according to default.
- Default store asynchrony is <VAR>x</VAR> kbytes.
-
-</PRE>
-<P>If the <B>-verbose</B> flag is combined with arguments that set values
-(<B>-files</B> and <B>-kbytes</B>, or <B>-allfiles</B>, or all
-three), there is a message that confirms immediately that the setting has
-taken effect. When included without other arguments or flags, the
-<B>-verbose</B> flag reports the default store asynchrony only.
-<P><STRONG>Examples</STRONG>
-<P>The following command enables the Cache Manager to return control to the
-application program that closed the file <B>test.data</B> when 100
-kilobytes still remain to be written to the File Server. The
-<B>-verbose</B> flag produces output that confirms the new setting, and
-that the default store asynchrony is zero.
-<PRE> % <B>fs storebehind -kbytes 100 -files test.data -verbose</B>
- Will store up to 100 kbytes of test.data asynchronously.
- Default store asynchrony is 0 kbytes.
-
-</PRE>
-<P><STRONG>Privilege Required</STRONG>
-<P>To include the <B>-allfiles</B> argument, the issuer must be logged in
-as the local superuser <B>root</B>.
-<P>To include the <B>-kbytes</B> and <B>-files</B> arguments, the
-issuer must either be logged in as the local superuser <B>root</B> or have
-the <B>w</B> (<B>write</B>) permission on the ACL of each file's
-directory.
-<P>To view the current settings (by including no arguments, the
-<B>-file</B> argument alone, or the <B>-verbose</B> argument alone),
-no privilege is required.
-<P><STRONG>Related Information</STRONG>
-<P><A HREF="auarf058.htm#HDRAFSD">afsd</A>
-<P>
-<HR><P ALIGN="center"> <A HREF="../index.htm"><IMG SRC="../books.gif" BORDER="0" ALT="[Return to Library]"></A> <A HREF="auarf002.htm#ToC"><IMG SRC="../toc.gif" BORDER="0" ALT="[Contents]"></A> <A HREF="auarf163.htm"><IMG SRC="../prev.gif" BORDER="0" ALT="[Previous Topic]"></A> <A HREF="#Top_Of_Page"><IMG SRC="../top.gif" BORDER="0" ALT="[Top of Topic]"></A> <A HREF="auarf165.htm"><IMG SRC="../next.gif" BORDER="0" ALT="[Next Topic]"></A> <A HREF="auarf284.htm#HDRINDEX"><IMG SRC="../index.gif" BORDER="0" ALT="[Index]"></A> <P>
-<!-- Begin Footer Records ========================================== -->
-<P><HR><B>
-<br>© <A HREF="http://www.ibm.com/">IBM Corporation 2000.</A> All Rights Reserved
-</B>
-<!-- End Footer Records ============================================ -->
-<A NAME="Bot_Of_Page"></A>
-</BODY></HTML>
git://git.openafs.org / openafs.git / blobdiff