[CUWiN-Dev] min RAM required for upgrade?

[David Young]

On Wed, Jan 04, 2006 at 04:34:34PM -0600, Bill Comisky wrote:
> I was trying to upgrade an older soekris board that had only 32 MB of RAM 
> compared to 64 for most of our boards.  tmpfs reserves 4MB for the system, 
> so if the memory use during the upgrade gets to high then $tmpdir becomes 
> unwritable if it is on /mfs.  This kills the script as it attempts to 
> write the fstab file to $tmpdir (looks like it would affect the signal 
> handling too since $abort is written to $tmpdir).
> 
> I feel like I've upgraded this node in the past, but it could have been 
> before switching to tmpfs or perhaps with an older upgrade script that 
> didn't write to tmp files?
> 
> Any ideas?  Maybe:
> Free memory by stopping some things before starting the 
> upgrade?
> Compile tmpfs to have a lower reserved memory limit? 

I can make that configurable through sysctl(8), but you suggest some
less expensive workarounds:

> Unmount/remount after untar'ing the archive (see memory use below)? 

I do not expect that to help unless the node runs a kernel that pre-dates
some changes to tmpfs that make it reclaim pages from the file cache.

> Use $tmpdir on mounted partition instead of /mfs?

That is a good bet.

Dave

-- 
David Young             OJC Technologies
dyoung at ojctech.com      Urbana, IL * (217) 278-3933