Memory for -B using SCO Unixware 7.1.4

ron

ron

Member
I've used Progress on Solaris for a long time. Now I'm dealing with a large number of small servers running Progress 9.1D on Unixware.

I'm trying to get a handle on how to manage memory. The servers have different memory sizes - some with 256 Mb and others range up to 2 Gb. Existing scripts determine a value for -B using:

/sbin/memsize -g -f8192 | /bin/awk '{print $1}'

I haven't come across "memsize" before. <memsize -g> seems to show the total amount of installed RAM - not what's available. Thus it seems that the value determined for -B will be too great.

Anyone know about Unixware who could comment?

Thanks,
Ron.
 
That sounds like a bad idea to me.

I could see using something like 80% of memsize as an upper limit on the total of -B for all databases started on the system. But if the script is using that as the value of -B for any and all databases being started that's just crazy.

Oh and 9.1D is, of course, ancient, obsolete and unsupported. I'll refrain from commenting about the OS.
 
Ha, ha! I would have been disappointed, Tom, if you hadn't commented about using an old version of Progress!! However - I am not "in charge" and have only just arrived as a contractor. They do have plans to move away from Unixware - and to move up to Progress 10. I have no control over that.

However - I guess you are agreeing with me that using 100% of memsize for -B is pretty crazy. Since I'm new to Unixware and the <memsize> command - I just wanted some confirmation.

Thanks,
Ron.
 
Thanks for that - but unfortunately the one question that I still can't find an answer to is: how much memory is UNUSED (ie, "available") at this moment?
 
If that means that you're hoping to get something useful in this endeavour from sar -r then I am afraid you do not have what you need. sar -r is useless.
 
Thanks <sboarduk> for the link to get top - I now have it.

Tom: sar -r gives the same value for "available unused memory" as top - and the value does look "reasonable". Are you sure sar -r is no good? What would you suggest instead?
 
Top and sar are both reporting on VM not "physical RAM". Modern operating systems use all available RAM all the time -- so for all intents and purposes there is no "unused memory".

SFAIK there is no simple command which will tell you what you want to know -- you have to sit down and put together a "memory budget". Figure out how much RAM the various bits of your system are going to require and make sure you have it. Then you have to monitor things like page-outs, process deactivation and swapping to make sure that you haven't exceeded your budget.

"Top" varies from OS to OS and release to release but if yours shows something like "buffers" that is probably as close as you can get to a simple view of how much "available" RAM your system has. This is showing filesystem buffers. The OS uses any RAM that it hasn't got a better use for for these buffers. If there is lots of free RAM in that category then you probably have enough to do something with it. (You shouldn't need more than 2% to 5% of your RAM for filesystem buffers -- but there is often a lot more than that being used...)
 
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