Re: raw devices in linux (O_DIRECT)

Hi, in your Machine Specific Notes you should see something like this: ------------------------------------------------------- 3. Kernel Asynchronous I/O (KAIO) Asynchronous I/O is supported by the official Linux kernel since version 2.6.x. IBM Informix Dynamic Server supports Kernel Asynchronous I/O (KAIO) on character devices (a.k.a. raw devices) and block devices. It is enabled by default, and can be disabled by setting the environment variable KAIOOFF=1 in the environment of the process that brings up the server. ... Note that the libaio.so library is required, regardless of the distribution or kernel level. At the time of writing, IBM Informix Dynamic Server requires a minimum of libaio 0.3.96-3. ------------------------------------------------------- Where the last paragraph is exactly what Sandor has pasted into the e-mail before. Which information do you think is missing ? Can you be more specific ? Regards, Martin -- Martin Fuerderer IBM Informix Development Munich, Germany Information Management owner-informix-list@iiug.org wrote on 04.03.2005 16:22:59: > Hi Sandor: > > Without the library libaio I got > > 08:32:46 libaio.so.1: cannot open shared object file: No such file or> directory > 08:32:46 Please install libaio package. See machine notes. > 08:32:46 Warning: Kernel Asynchronous I/O is disabled.> > After installing the library and leaving raw devices disabled in kernel > (default), IDS 10 uses KAIO. > > [root@tina 0333]# cat /proc/sys/fs/aio-nr > 32768 > [root@tina ~]# onstat -g iov > IBM Informix Dynamic Server Version 10.00.UC1 -- On-Line -- Up 01:21:20 --> 1799820 Kbytes > > AIO I/O vps: > class/vp s io/s totalops dskread dskwrite dskcopy wakeups io/wup errors > kio 0 i 0.0 119 119 0 0 275 0.4 0 > kio 1 i 0.0 195 185 10 0 502 0.4 0 > kio 2 i 0.0 40 23 17 0 170 0.2 0 > msc 0 i 0.0 13 0 0 0 14 0.9 0 > aio 0 i 0.0 161 16 8 0 161 1.0 0 > aio 1 i 0.0 2 0 0 0 3 0.7 0 > aio 2 i 0.0 0 0 0 0 1 0.0 0 > pio 0 i 0.0 1 0 0 0 2 0.5 0 > pio 1 i 0.0 0 0 0 0 1 0.0 0 > lio 0 i 0.0 0 0 0 0 1 0.0 0 > > There is no more information on release notes but machine notes mention > the support of KAIO in kernel 2.6 but BOT the automagically activation. > > Thanks > > > > Sandor Szabo escribi': > > Hi Fernando, > > > > I have some information regarding the O_DIRECT flag. > > > > IDS V10 detects automatically that it runs on Linux Kernel 2.6 and if KAIO > > is enabled then it turns on the O_DIRECT flag! > > > > To enable KAIO: > > > > The libaio.so library is required, regardless of the distribution > > or kernel level. At the time of writing, IBM Informix Dynamic Server V10.0 > > requires a minimum of libaio 0.3.96-3. > > > > Please also read the release notes for more information! > > bye > > Sandor > > > > IBM Informix Development Munich > > Information Management > > Hollerithstra'e 1 > > 81829 Munich Germany > > > > > sending to informix-list sending to informix-list