The immortal aioserver Post: 302958331

Sponsored Content

Operating Systems AIX The immortal aioserver Post 302958331 by bakunin on Wednesday 21st of October 2015 10:29:56 AM

10-21-2015

Registered User

Quote:

Originally Posted by agent.kgb

if you want to see them dead, try to change some parameters in the system ;-)

While this is very true - in fact, the "aio" stands for "Asynchronous I/O" and the processes are controlled by tuning parameters - it is most probably a bad idea to do so on a database system. If memory serves correctly Oracle always requested to have asynchronous I/o switched on during the installation and the performance of the db-writer process greatly suffered when it was switched off.

Anyways, the "aioserver" processes are definitely not reponsible for preventing the unmount of the filesystems, so it won't have any positive effect even if it succeeds (although this, given that they are kernel processes is highly unlikely).

The number, btw., of the main processes is dependent on the number of LCPUs the system has. I suppose your system has 8 CPUs configured and this is why you always see a minimum of 8 processes running.

I hope this helps understanding these processes.

bakunin

bakunin

View Public Profile for bakunin

Find all posts by bakunin

2 More Discussions You Might Find Interesting

1. AIX

AIOServer process question

Hi I've been trying to learn a bit more about AIOServer processes and how my company administers them, one question i have is, while checking, most of my servers show a memory overhead of about 448 k per aioserver process (nmon -A) however i have found a few with figures of 67 or 56k. Most...

2. AIX

aioserver query

Hi Gurus, What is the recommended value for aioserver in aix 5.3 current value is 16384 And used is ps -k|wc -l 4768 We usauslly get issues like slow server performance and query waiting time more etc. Regards newaix

LEARN ABOUT HPUX

aio_max_ops

aio_max_ops(5)							File Formats Manual						    aio_max_ops(5)

NAME

       aio_max_ops - maximum number of POSIX async I/O operations that can be queued at any time

VALUES

   Failsafe
   Default
   Allowed values
       The minimum value allowed is The maximum value allowed is The value is further constrained in that it must be greater than or equal to

       Specify a positive integer value.

DESCRIPTION

       This parameter places a limit on the system resources that can be consumed if large numbers of POSIX asynchronous I/O operations are queued
       on the system at the same time.	This parameter limits the ability of competing processes to overwhelm the system  with	large  numbers	of
       asynchronous I/O operations and the memory they require.

       Each enqueued asynchronous operation requires allocation of system memory for its internal control structure, thus making this limit neces-
       sary.  In addition to the system-wide limit, there is a per-process limit that is controlled using the argument to and calls.

       limits the number of operations that can be contained in a single call from a given process, and the value of must be  sufficient  to  meet
       the  reasonable	needs  of all processes that are making simultaneous or nearly simultaneous calls without jeopardizing overall system bal-
       ance.

   Who Is Expected to Change This Tunable?
       System administrators that run applications requiring heavy usage of POSIX AIO to file systems.

   Restrictions on Changing
       This tunable is dynamic (tuning will take effect immediately on the running system).

   What Other Tunables Should Be Changed at the Same Time as This One?
       The value assigned to must be greater than or equal to

WARNINGS

       All HP-UX kernel tunable parameters are release specific.  This parameter may be removed or have its meaning changed in future releases	of
       HP-UX.

       Installation  of  optional  kernel  software, from HP or other vendors, may cause changes to tunable parameter values.  After installation,
       some tunable parameters may no longer be at the default or recommended values.  For information about the effects of installation  on  tun-
       able  values,  consult  the documentation for the kernel software being installed.  For information about optional kernel software that was
       factory installed on your system, see at

AUTHOR

       was developed by HP.

SEE ALSO

       kctune(1M), sam(1M), gettune(2), settune(2), getrlimit(2), setrlimit(2), aio(5), aio_listio_max(5).

							     Tunable Kernel Parameters						    aio_max_ops(5)