[Summary] KAIO:out of OS resources

From: Mukesh Soni <MSONI_at_tuc.com>
Date: Tue, 27 Jan 1998 16:34:45 -0600

My original problem was:
-------------------------------
We have 4100 server, 4 CPU, 1.5 GB, running DU4.0B (including
Patches) / informix 7.23FCI / PeopleSoft 6.1

1. Informix suggests to use Kernel aio for better performance. But
when we use kernel aio, informix gives me error

KAIO: out of OS resources, errno = 35, pid = 13964

sysconfig command gives me following result.
# sysconfig -q kio
kio : function not implemented

It is advertised that Digital Unix 4.0B supports kernel async io. We are
using advfs for filesystem, raw partitions for informix and raid 5.

#sysconfig -q rt
rt:
aio-max-num = 716
aio-task-max-num = 333
aio-max-percent = 1
aio-max-retry = 0
aio-retry-scale = 4
sigqueue-max-num = 64
 
                                     -------****-------

Thanks a lot to George Guethlein<GGuethlein_at_GiantOfMaryland.com>
for the notes on configuring informix for DEC Alpha environment. Please
respond if anybody needs them.

                                    ---------***--------

Thanks a lot to Dr. Tom Blinn. He responded ..
The file /usr/include/errno.h lists the kernel error numbers. If you look
at the file you'll see that for a V4.0x system, error number 35 is this:

/* non-blocking and interrupt i/o */
#define EWOULDBLOCK 35 /* Operation would block */
#define EAGAIN EWOULDBLOCK /* ditto */
#define EINPROGRESS 36 /* Operation now in progress */
#define EALREADY 37 /* Operation already in progress */

that is, "operation would block". EAGAIN is an instruction to the process
to try the operation again; EWOULDBLOCK or EAGAIN is generally
returned when
the process tries to do an operation that might block, and doesn't want to
wait in a blocked state, so uses function codes that say to return an
error
if the operation would block. It is an EXPECTED error code when you are
using asynchronous (non-blocking) I/O.

                                        --------***-------

The same thing was posted to Informix and a very useful help came from
Auston Bouska <abouska_at_informix.com> to set following

aio-max-num = 4096
aio-task-max = 2048

I have changed the parameters and observing the system since the error
comes only once or twice a day when system load is more.

Thanks and regards,
Mukesh Soni
msoni_at_tuc.com
Received on Tue Jan 27 1998 - 23:35:52 NZDT

This archive was generated by hypermail 2.4.0 : Wed Nov 08 2023 - 11:53:37 NZDT