Yanking power on QNX4

Can anyone tell me if there is a problem with simply
turning off power to a QNX4.25, Photon 1.13 machine
without doing a graceful shutdown of the OS?

I have an application that, once running, makes no use
of the hard disk (e.g. no file I/O at all). Yet this machine is
in an environment where power may be unceremoniously
“yanked”. Will repeated power yanks eventually lead to
a corrupted file system or other OS problems?

Thanks,
Jay


Jay D. Marchetti
President
Pittsburgh Firmware, Inc.
4068 Mount Royal Blvd., Suite 100
Allison Park, PA, USA 15101
Tel / Fax : 412-487-6640
Web: www.pittsburghfirmware.com
Email: marchetti@pittsburghfirmware.com

From experience (i.e. not an official answer)
as long as all you did was load QNX/Photon/Your Ap then it should be
safe to just yank power. If you’ve written ANYTHING to the hard
drive, then all bets are off. Then there’s always the philosophy,
“If I didn’t write it, I don’t care about it.” ;~} Just kidding.
But make sure you know what the OS started benieth your feet.

So, if you ever do any config changes, make them and shut
down gracefully. Then power up again and you safe to go.



Jay Marchetti <jmarchetti@carco-east.com> wrote:
JM > Can anyone tell me if there is a problem with simply
JM > turning off power to a QNX4.25, Photon 1.13 machine
JM > without doing a graceful shutdown of the OS?

JM > I have an application that, once running, makes no use
JM > of the hard disk (e.g. no file I/O at all). Yet this machine is
JM > in an environment where power may be unceremoniously
JM > “yanked”. Will repeated power yanks eventually lead to
JM > a corrupted file system or other OS problems?

JM > Thanks,
JM > Jay

Jay Marchetti wrote:

Can anyone tell me if there is a problem with simply
turning off power to a QNX4.25, Photon 1.13 machine
without doing a graceful shutdown of the OS?

I have an application that, once running, makes no use
of the hard disk (e.g. no file I/O at all). Yet this machine is
in an environment where power may be unceremoniously
“yanked”. Will repeated power yanks eventually lead to
a corrupted file system or other OS problems?

Various things can be done to improve reliability (reduce the chance of
corruption). At the most extreme you can turn async writes off on the file
system (note, that this improved fault tolerance is not free, you’ll pay a
severe performance penalty).

Rennie