topic Re: vhand in Operating System - HP-UX

vhand

jim bidebo — Tue, 04 Dec 2001 13:16:27 GMT

running hp-ux 10.20

occationaly a process called vhand takes 110% of the CPU, and it leads to that the mashine locks up.
ive tried to locate the file with find / -name vhand -print.. but it doesnt find anything..
does anyone know where this process comes from???

Re: vhand

Duncan Edmonstone — Tue, 04 Dec 2001 13:20:03 GMT

vhand is the daemon responsible for paging data out of memory into swap.

Take a llok at the output of swapinfo -t
this will tell you about the current state of your swap utilisation.

IF vhand is taking up all your CPU time then there's a very high chance your machine is thrashing - take a look at the out
you probably need more memory, or need to look at the memory utilisation of your application(s)

HTH

Duncan

Re: vhand

harry d brown jr — Tue, 04 Dec 2001 13:21:56 GMT

vhand is the virtal io handler. What does your swap and memory look like (use glance)?

live free or die
harry

Re: vhand

Mike Hassell — Tue, 04 Dec 2001 13:48:58 GMT

Jim,

Sounds like your in need of more physical memory as 'vhand' daemon is overloaded with moving data to and from the swap space.
As the others have mentioned above, this is considered "trashing". This can be overcome if you can decrease the number of running processes or increasing the amount of physical memory on the box. Hope that helps.

-Mike

Re: vhand

Anthony deRito — Tue, 04 Dec 2001 13:50:10 GMT

If vhand is doing a lot of work then you have too little swap space. Run swapinfo -tma and check out the values of "PCT USED" column. If these numbers are high (70 - 100) then adding swap should fix your problem. Disk is cheap... add swap using the swapon command. Paging out to disk is normal, however, as one post already mentioned, it is counter productive if you are swapping to the point where you are thrashing. HP-UX is a virtual memory operating system so the memory management subsystem will do its best to manage memory resources by paging... but there has to be enough of swap.

Hope this helps.

Tony