NAME

viceup - backup facility (AFS only)

SYNOPSIS

viceup [ -o ] [ -v ] sourcedirectory targetdirectory

DESCRIPTION

Viceup is a program that will selectively copy files from one directory to another.  That is, used more than once, it only copies files which have changed. 

OPTIONS

-o Copies the files but does not copy the Vice access list information. 

-v Turns on verbose output. 

NOTES

Like the cp(1) -p, viceup preserves the date on any file it copies.  This feature is useful if you have programs which assume that two files with the same date have the same contents; you can move files around without changing their dates.  In addition, some programs like the make(1) program compare dates of files to see whether one was made out of another.  In some cases you can save unnecessary recompiling by using viceup if you want to copy a whole directory. 

Viceup is often used by people who want to copy files to their local disk so they can work apart from AFS.   More information on that, including some important warnings, is in the section of this text called "Maintaining files locally."

Viceup will copy a file from the source directory to the target directory if 1) the file isn’t already in the target directory; 2) the write date on the two versions differ; or 3) the lengths of the two versions differ. 

Viceup is designed to preserve AFS access list information.  When you viceup files from the local disk, none of them will have this information and you will see an error message.  You can ignore it. 

If a file in the target directory has write permission for the owner turned off (e.g. chmod 400 filename), viceup will not overwrite that file. 

MAINTAINING FILES LOCALLY

Maintaining files locally (that is, apart from the Andrew file system) should only be done on a machine owned by the user, not a public machine.  Even if you own the machine, this use of the local disk is not recommended as a standard practice because of the potential problems listed below. 

Pros and Cons of maintaining files locally

Pros:  Why you might wish to maintain files locally

1.  You will have access to them even when the network or a file server is down. 
2.  You may think the response time will be better, but since any file that you are using which is stored in the Vice file system is cached on your disk automatically and some programs tend to remain in the cache for some time, this effect should be marginal.
3.  The information that you are storing must be very private (e.g., an exam you’re preparing).  The file system protections provided by the Andrew file system approximate those of a time-sharing system.
4.   If the file system destroys your files, you still have copies of them.

Cons:  Why you might not wish to maintain files locally

1.  You can get at them only from the particular machine they are on. 
2.  No one will back up the files.  If the local disk develops problems, you may lose work.
3.  If the files are system functions (e.g., Edittext) which may be updated ocassionally, you will not see those changes.
4.  Unless you clearly understand the entire set of files you need for a particular activity, you will often find that you can’t work without the Andrew file system anyway because you have forgotten a few files.
5.  If you only have 40 or 70 mb of disk space, you’ll be unable to store many large programs or files.
6.  If others have access to the machine on which the files are stored, they will have access to those files, unless you take alternate steps.  You will have only the IBM/4.3 security mechanisms available to you.
7.  The organization of the local disk essential to full operation of the Andrew file system is not bullet-proof.  Experimentation could seriously compromise the full functionality of the machine as a client of the Andrew file system.

When you maintain files locally, use viceup to backup your files into the Andrew file system in case your local disk becomes corrupted.  If that happens, you can get copies back from the Andrew file system (at least, copies from the last time you viceup’d the files).  For users of private machines, here is the recommended procedure for maintaining files locally. 

1.  Create a subdirectory under /user with the name "stuff:"

mkdir /user/stuff

2.  Put whatever files you want there. 

3.  Create a corresponding "backup" directory in the Andrew File System, "~/stuff", and whenever you have work you don’t want to lose, copy /user/stuff to it:

cp -r /user/stuff ~

This will copy the directory /user/stuff, with all its contents, including subdirectories, into a subdirectory of the same name in your home directory. 

Or, you can selectively backup /user/stuff by typing

viceup /user/stuff ~/stuff This page intentionally left blank. 

PRPQs 5799-WZQ/5799-PFF: IBM/4.3  —  Sept 1988