Re: RES: RES: Bug on cp

[David T-G]

Jenner --

...and then Borges, Jenner Gigante (BR-Paulista Seguros) said...
% 
% Hello David!

Hi again!


% I have RAID 0+1.

OK...


% How can I see the inodes and increase them ?

Hmmm...  I forget for ext2, but it is probably in the mount or mkfs or
tunefs commands.  Check your man pages.  I don't think you can increase
inodes without destroying and recreating the filesystem :-(


% Yes, I am going from ext2 to ext2.

OK.


% Last night I follow the steps from backup and I think because we didn´t run 
% a update procedure , the datafiles were not accessed and the backup finished
% succesfull, but the messages :

Hmmm...


% Dec 31 01:00:22 dtmart kernel: __alloc_pages: 0-order allocation failed.
% Dec 31 01:00:40 dtmart last message repeated 826 times
% Dec 31 01:00:40 dtmart kernel: failed.

That can't be good!

I forgot to ask: how much RAM and swap do you have in the system, and
what does top say?

I searched google for 'kernel: __alloc_pages: 0-order allocation failed'
and found numerous mailing list post, most relating to bigmem.  I think
that we can safely say that this is not a problem for cp.


%  
% still  appear on my /var/log/messages.
% During the cp process the top command showed me that the kswapd and bdflush
% and 
% cp were consuming a lot of CPU.

Makes sense; you were shoveling a lot of data through the system.


% 
% Do you know if my kernel parameters were well tuned for these copy process ?
% 
% # Disables packet forwarding
% net.ipv4.ip_forward = 0
% # Enables source route verification
% net.ipv4.conf.all.rp_filter = 1
% # Disables the magic-sysrq key
% kernel.sysrq = 0
% * Shared and Semaphores Parameters
% kernel.shmmax=2059460000
% kernel.shmall=2059460000
% kernel.shmmni=100
% kernel.shmseg=20
% kernel.shmmin=1
% kernel.semmni=500
% kernel.semmns=1500
% kernel.semmsl=200

I'm not absolutely sure, but all of the shared memory and semaphore
settings are just going to be for ordinary DB processes and not pertinent
to a cp like this.  I don't think that there are any knobs to bump up
disk-to-disk performance, like maybe a buffer allocation size; I think
that the system handles that on its own based on what resources it has.


% 
% Thanks again and happy new year !!!

And to you :-)  Good luck!


:-D
-- 
David T-G                      * There is too much animal courage in 
(play) address@hidden * society and not sufficient moral courage.
(work) address@hidden  -- Mary Baker Eddy, "Science and Health"
http://www.justpickone.org/davidtg/    Shpx gur Pbzzhavpngvbaf Qrprapl Npg!

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