Scratch partition...

Robert G. Brown rgb at phy.duke.edu
Fri Dec 7 14:15:15 PST 2001


On Fri, 7 Dec 2001, Joel Jaeggli wrote:

> > 
> > Ok, but in my case, must i create this partition in the linux instalation?
> 
> nope...

Unless you want it to survive a reinstall.  That is, you can create a
scratch directory inside your basic root partition and give it the
permissions of /tmp (we often call scratch /xtmp, for example).
However, /xtmp will then get recreated if you do a full reinstall of /,
and any data stored there will be lost.

If you create an actual partition for /xtmp, you can easily arrange for
it to be skipped in subsequent e.g. kickstart reinstalls.  That way if
you for any reason (say a version upgrade, a corrupted library) need to
reinstall the root partition you can do so without worrying about
preserving anything a user may have written to /xtmp.

Another thing to worry about is whether or not you back up "scratch".
We don't (and I'd say that traditionally one doesn't) -- anything in
/xtmp won't be cleaned out except on a FIFO basis when it fills and will
likely survive a reinstall or upgrade, but neither will it be backed up.
People use it for files that they CAN recreate by e.g. rerunning a
numerical application but that they would RATHER stick around, or for
particularly large initialization files.

   rgb

>  
> > Thanks,
> > 
> > Geraldo Pereira de Souza (geraldo at cic.unb.br)
> > Laboratório de Sistemas Integrados e Concorrentes - LAICO
> > Universidade de Brasília - UNB
> > 
> > ----- Original Message -----
> > From: "Joel Jaeggli" <joelja at darkwing.uoregon.edu>
> > To: "Geraldo Pereira de Souza" <geraldo at cic.unb.br>
> > Cc: <beowulf at beowulf.org>
> > Sent: Friday, December 07, 2001 6:11 PM
> > Subject: Re: Scratch partition...
> > 
> > 
> > > scratch is an old unix convention for a storage space which nobody owns
> > > (so using it doesn't affect anyone's quota) but which is more stable than
> > > /tmp (ie. it won't get flushed every day, or after reboots, or if it runs
> > > out of space)...
> > >
> > > joelja
> > >
> > > On Fri, 7 Dec 2001, Geraldo Pereira de Souza wrote:
> > >
> > > > People,
> > > >
> > > > In http://www.cacr.caltech.edu/research/beowulf/tutorial/beosoft/
> > > > Starling describe how to build a beowulf system using some PC´s.
> > > > I´m based in the tutorial to construct a beowulf system with 8 Pcs.
> > Starling describe in the tutorial the the configuration of the nodes to
> > export the filesytem.
> > > > In a point he say:
> > > >
> > > > "We decided to export scratch partition from all nodes and use autofs to
> > mount these from any node upon rquest. Our exports file looks like:
> > > > /scratch n???.cacr.caltech.edu(rw,no_root_squash)"
> > > >
> > > > I´m new with administration of linux, but my question is: What is
> > scratch partition?
> > > > Must i create the directory /scratch ?
> > > >
> > > >
> > > > Thanks,
> > > >
> > > >
> > > > Geraldo Pereira de Souza (geraldo at cic.unb.br)
> > > > Laboratório de Sistemas Integrados e Concorrentes - LAICO
> > > > Universidade de Brasília - UNB
> > > >
> > >
> > > --
> > > --------------------------------------------------------------------------
> > > Joel Jaeggli       Academic User Services   joelja at darkwing.uoregon.edu
> > > --    PGP Key Fingerprint: 1DE9 8FCA 51FB 4195 B42A 9C32 A30D 121E      --
> > > The accumulation of all powers, legislative, executive, and judiciary, in
> > > the same hands, whether of one, a few, or many, and whether hereditary,
> > > selfappointed, or elective, may justly be pronounced the very definition
> > of
> > > tyranny. - James Madison, Federalist Papers 47 -  Feb 1, 1788
> > >
> > >
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> 
> 

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu






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