SUM: Swap space & hard drives

From: Colin Brooks <cbrooks_at_nature.berkeley.edu>
Date: Wed, 10 Jul 1996 11:22:16 -0700

Thank you to the following people for responding:

alan_at_nabeth.cxo.dec.com
Gyula Szokoly <szgyula_at_skysrv.Pha.Jhu.EDU>
rbae_at_esri.com (Ryan Bae [ESRI-Redlands])
Dale Cook <cdm_at_hyperk.com>
Roddy McColl <roddy_at_visual-ra.swmed.edu>
"Martyn Brown, Lincoln University" <brown_at_whio.lincoln.ac.nz>
"Jeffrey C. Ollie" <jeff_at_ollie.clive.ia.us>
Craig Makin <Craig_Makin.DOLA_at_notes.dola.wa.gov.au>
Dougal Scott <dwagon_at_aaii.oz.au>
bremner_at_cs.mcgill.ca
Clifford Krieger <ckrieger_at_psi.prc.com>
"Dr. Tom Blinn, 603-881-0646" <tpb_at_zk3.dec.com>
Hellebo Knut <Knut.Hellebo_at_nho.hydro.com>
bouchard_l_at_decus.fr (Louis Bouchard - Bouygues Telecom)

----
Most people had the same response - I would need to back up my data currently
on rz3c, and then repartition the hard drive so that I would have several
partitions 
to choose from.  I would then reload the data on one of the partitions
(probably rz3g), 
and use a remaining one (probably rz3b) for swamp space.  One person mentioned
using a swap file, but Digital UNIX 3.2c doesn't support this yet, according
to "man swapon".  I've also considered adding a 3rd hard disk to use mostly
as swap.
Here are 3 representative examples of the responses that I got:
--------- (1) ----------
NO! Don't even think about that. Instead: go to single user mode,
back up /big to tape/nfsmounted partition/whatever, change the partition table,
create new file systems, restore the backup. You can't change the partition
size of a file system...
---------- (2) -----------
1. backup rz3c (/big filesystem)
2. zero the disklabel for rz3c
3. rewrite the disklabel as you wish, either std DEC or your requirements
4. mount /big on which ever partition you require
5. restore /big
6. add rz3b to fstab indicating it is another swap partition.
----------- (3) -------------
Be careful ! The partition table is on the first block of your disk. 
If you use partition a for swapping, you might end up with a funny looking disk
whenever your system start swapping.
	It would be better to use partition "a" as a file system and push your
swap area on another partition.  It is not without a reason that DEC is using
partition "a" for root and "b" for primary swap on a standard installation.  If
the partition "a" is used for swap, the partition table will be overwritten as
swap starts filling up (the swap space being "raw device" disk space).
-----------------------------
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*Colin Brooks                       						    *
*GIS Program Analyst                   Also at:					    *
*Hopland Research & Extension Center | Integrated Hardwood Range Management
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*4070 University Rd.                 | ESPM at UC-Berkeley			    *
*Hopland, CA  95449                  | 160 Mulford Hall			      	    *
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*cbrooks_at_nature.berkeley.edu         | TEL: 510-643-1136  FAX: 510-643-5438
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Received on Wed Jul 10 1996 - 21:05:09 NZST