Sudden Reboots

[Doug Ambrisko]

Jim Durham writes:
[ Charset ISO-8859-1 unsupported, converting... ]
| On Friday 01 October 2004 12:36 pm, Doug Ambrisko wrote:
| > Jim Durham writes:
| > | I have had this problem now with at least 3 FreeBSD servers over a period
| > | of about 2 years. I had put it down to some hardware problem but it seems
| > | to be too much of a coincidence with 3 different machines doing the same
| > | thing.
|
| > How much memory are in these system?. 
| The Dell is a Dual Xeon 2650 with 2gb or Ram. The ISP's box has only 256 megs 
| or ram and the business customer's box has 512.

That shouldn't be much of an issue then
 
| > If you have 3G or more you end 
| > up with very little left for the kernel in the 2G space
| 
| Can you elaborate on why this is?

I did somewhat here:

| > If you only have a few meg. left it doesn't take many processes to
| > fork etc. then you machine blows up.  The bge driver for example takes
| > 4M each for the jumbo packet handling.  You can recover some of this
| > memory via loader.conf tunables or bump KVA_PAGES in your kernel
| > config file.  Still once this memory is put into the zone allocator
| > (vmstat -z) in -stable it is gone from the system even if that bucket
| > isn't fully used or needed :-(

Most of these zones scale based on total memory which.

| What would you expect to see in the logs on such a scenario? I'm surprised to 
| see nothing.

Unless you have kernel dumps and savecore settup you will miss the panic.
When a system panics it can't right our to /var/log/*

| > Ironically the more memory you put in a system the less you can do with
| > the system!
| >
| > A lot of people are starting to run into this problem since large memory
| > machines are cheap.
| 
| Well, I don't think 2gb is large by your standards?

No it isn't.  3-4G machines start to hit this.  Also if you bump up things 
like mbufs and cluster you start to hit this limit.

Doug A.