[comp.sys.sgi] swap space

"0000-Admin@UCBVAX.BERKELEY.EDU (10/21/90)

I'm trying to build GNU EMACS on a PI.  I have successfully built it before
on a 4D80, but here I've not been able to successfully do the final temacs
statement -- which the PROBLEMS file tells me is because I have insufficient
swap space.  This seems very possible to me, but I don't know how to increase
the amount of swap space I have to complete the compilation.
Any descriptions of how swap space works would be appreciated.
Thanks,
Eugene Gholz
(eugholz@athena.mit.edu)

dabay@BRL.MIL ("Dave M. Dabay", SGI|stay) (11/20/90)

Also swap needs to be at least as large as your real memory so that any
system core dumps would be complete... Nice to have to analyze....

mcdonald@AEDC-VAX.AF.MIL (04/17/91)

I am posting this for an associate:

He has a 4D25 PI, and he needs to reconfigure the amount of swap space it has
available in order to run some image processing software.  He told me that
his manual said it need 150 Megabytes of swap space.

What are the steps in reconfiguring the amount of swap space available on a PI?


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olson@anchor.esd.sgi.com (Dave Olson) (04/17/91)

In <9104161701.AA06206@ccfiris.aedc> mcdonald@AEDC-VAX.AF.MIL writes:

| I am posting this for an associate:
| 
| He has a 4D25 PI, and he needs to reconfigure the amount of swap space it has
| available in order to run some image processing software.  He told me that
| his manual said it need 150 Megabytes of swap space.
| 
| What are the steps in reconfiguring the amount of swap space available on a PI?

Completely back up the system (you could get buy with just /usr, but that
is risky).  VERIFY that your backups are valid!

Halt the system, and boot the standalone fx via 'boot dksc(0,1)stand/fx --x'
Press return for the first 3 prompts, then type "label/set/part".
Change the size of the swap partition (partition 1), and then change
partition 6 to match (i.e., increase the start of partition 6 and decrease
the size).  Then type "../sho/part" to make sure it is correct.  If so, type
"../sync", then "/exit".  You are now back at the PROM monitor.

If done correctly, partition 0 (the root partition) is still valid, so type:
"boot dksc(0,1)unix initstate=s". Once you are up in single user mode,
do "mkfs /dev/dsk/dks0d1s6" to create a new (much smaller!) /usr
filesystem, mount it, and then restore the files.  Hopefully they will all
still fit.

If you have no files at all on the system, and haven't configured it,
you could just completely reinstall the system instead of backing up
and restoring /usr, but most people have already got the system running
when they find they need more swap space.
--

	Dave Olson

Life would be so much easier if we could just look at the source code.

lara@sgi.com (Lara J Allen) (04/18/91)

In article <1991Apr17.031917.15633@odin.corp.sgi.com> olson@anchor.esd.sgi.com (Dave Olson) writes:
>In <9104161701.AA06206@ccfiris.aedc> mcdonald@AEDC-VAX.AF.MIL writes:
>
>| I am posting this for an associate:

might want to see if your company gets _Pipeline_  
  This is CSD's 'newsletter' to the world.  people
  under support should get it.  there was a fantastic
  article on how to redo swap space.
if not, email pipeline@sgi.com

>Completely back up the system (you could get buy with just /usr, but that
>is risky).  VERIFY that your backups are valid!
i too, cannot stress this enough.
please make certain you backed up what you thought you did.

i usually tell people to make two sets of backups.  one complete
  and one specific (/usr/people/$USER and /etc)

>Press return for the first 3 prompts, then type "label/set/part".
>Change the size of the swap partition (partition 1), and then change
>partition 6 to match (i.e., increase the start of partition 6 and decrease
>the size).  Then type "../sho/part" to make sure it is correct.  If so, type
>"../sync", then "/exit".  You are now back at the PROM monitor.

to determine how to change the size, you're going to need
  to look at the label and find out how many sectors/trac and
  how many tracks/cylinder.
The best way is: before bringing down the system, do a
  prtvtoc and print it out.  keep it next to you at all
  times.    

then, the magic equation is:

Total # of Cylinders = (Desired Size of Swap in Mbytes)/{(# bytes/sector)x
				 (# sectors/track)x(#tracks/cylinder)}

so, if a machine had 512 bytes/sector, 45 sectors/track and
  9 tracks/cylinder, and in this case, wanted 150M of swap,
Total # of Cylinders = 150000000/(512x45x9)
	   	     = 723.38
   		     = 724 cylinders

thus, the root would probably be 3 + 82
then the swap would be 85 + 725
then user would be 810 + whatever

you get the picture.

and like dave said, don't forget to rerun mkfs on the new user
  partition.  (i've seen a lot of problems where this was
  the cause)

lastly, please...once you've repartitioned...please don't
  reformat.


good luck!
if something i said doesn't make sense, let me know and i'll
  either put my foot in my mouth or clear up the mud

thanks!
lara

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