Showing results for 
Search instead for 
Did you mean: 

Increase maxfiles and maxusers

Go to solution

Increase maxfiles and maxusers

Hi admins.
I've an Oracle DB (880 Mb of SGA)(running on a V-class server (4 CPU, 4 Gb RAM, HP-UX 11.00). We have to migrate this DB on an L1000 (2 CPU and 2 Gb RAM; HP-UX 11.00). There are many kernel parameters that are different: for example, maxusers is 32 on l1000 and 400 on the V-class and maxfiles is 60 on l1000 and 2048 on the V-class. I've read that maxusers depends on the physical memory, so how much can I increase it? Up to 1024 or up to 2048?

Thanks in advance for your help.

Stefan Farrelly
Honored Contributor

Re: Increase maxfiles and maxusers

Maxusers doesnt really depend on the physical memory, just as a guideline you should set it depending on how much RAM you have.

For the important parameters I would simply copy them over to the L - set them to the same as on the V (maxusers, nproc, nfile, maxdsiz, maxtsiz, maxssiz, dbc_max & min etc.) With your SGA only being 880Mb on a 2Gb L class you should be fine memory wise with the kernel.
Im from Palmerston North, New Zealand, but somehow ended up in London...
Tom Geudens
Honored Contributor

Re: Increase maxfiles and maxusers

Hi Francesca,
I keep posting the following document in the forums ... but it is a very good one :-). It explains the kernelparameters (and their impact) in detail :

In short, I think (verify this) maxusers is ok at 32, but maxfiles will probably have to be raised to 2048 (well, maybe not that high, but 60 is definitely way to small) otherwise the database will not open.

Hope it helps,
A life ? Cool ! Where can I download one of those from ?
Honored Contributor

Re: Increase maxfiles and maxusers


Number of users are not depend on RAM.
what is present in the L-1000 is defaults.
while installing orcale we need to change some kernel parameters ( maxusers,maxfiles, shared memory, semaphores et all) change the parameters values to that of your V-class machine and proceed with migration
never give up
James R. Ferguson
Acclaimed Contributor

Re: Increase maxfiles and maxusers


'maxusers' controls the default values of 'nclist', 'nproc', 'nfile' and 'ninode'. That is, the value of 'maxusers' is employed to calculate other tunable values and has no other direct use. Increasing 'maxusers' increases memory consumption by growing the other tunable tables. It is a convenient way to tune several parameters in concert. For more information, see:



Re: Increase maxfiles and maxusers

Thanks for all your suggestions. I think I'll increase maxusers up to 128 (the recommended value in the HP-UX Performance Cookbook) and maxfiles up to 1024. I think I'll increase also maxuprc up to 523(actually it's 75) because all the connections (100- 150 simultaneously) are made "under" oracle user.