From: Herbert Poetzl (herbert_at_13thfloor.at)
Date: Mon 30 Dec 2002 - 06:16:55 GMT
On Sun, Dec 29, 2002 at 11:29:44PM -0500, Dinesh Mistry wrote:
> Ok so..
> 
> I checked the reverse DNS on each of the vserver's and they have no problems
> performing reverse DNS, they respond back pretty quickly in fact.
although you could not verify ns (or similar)
timeouts I would check /etc/nsswitch.conf for
entries like ...
passwd:     files nisplus nis
shadow:     files nisplus nis
group:      files nisplus nis
hosts:      files nisplus nis dns
and remove any evidence of nisplus and nis
if you do not have/use it (which is very unlikely
inside a virtual server ;)
> Maybe it's a memory or file handles thing like you suggest I guess I have a
> 2 fold question, where would I look for such things and how. Linux pretty
> much uses all the memory you throw at it so top is not very helpful.
cat /proc/meminfo
MemTotal:       904776 kB	(* what you have - kernel *)
MemFree:          4340 kB	(* what is unused *)
MemShared:           0 kB
Buffers:        436644 kB	(* page/filesystem caches as
Cached:         134904 kB	   well as inode/dentry and
SwapCached:      63852 kB	   swapped out pages *)
Active:         386504 kB	(* active memory pages *)
Inactive:       293704 kB	(* swapped out memory pages *)
SwapTotal:     2576312 kB	(* swap space total *)
SwapFree:      2333236 kB	(* swap space available *)
or use 'free' for a quick overview ...
> Secondly is there some sort of 'rule of thumb' to figure out how many VPS's
> you can run on a specific type of server CPU/MEM type calculation?
a 2CPU SMP machine can take 2-4 times more vservers
than a single CPU machine before it becomes unresponsive
about 25-30 average to low load vservers (~ 1000 processes)
almost fill up 512MB ram ...
best,
Herbert
> Any suggestions would be greatly appreciated.
> 
> --------------------------------------------
> Dinesh Mistry
> 
> YourHostDirect
> Better, Faster and more Reliable Hosting
> http://www.yourhostdirect.com
> --------------------------------------------
> 
> 
> -----Original Message-----
> From: Paul Sladen [mailto:vserver_at_paul.sladen.org] 
> Sent: Sunday, December 29, 2002 2:33 PM
> To: VServer Patch List
> Subject: Re: [vserver] Socket Timeout's SMTP DNS POP IMAP
> 
> On Sun, 29 Dec 2002, Dinesh Mistry wrote:
> > This is where it hangs, is this just a 'feature' of the vserver or am I
> 
> This isn't a feature.  You have a problem;  I occasionally see this on one
> box, often when it is under heavy load (or even just before it is about to
> `hang' in the way that everyone else describes. ;-)
> 
> Check file-handles, check out-of-memory, check if the box is actually doing
> some work;  in a similar but different problem, check whether any of the
> daemons are trying to do reverse lookups.
> 
> 	-Paul
> -- 
> Nottingham, GB
> 
>