Hi,
I make system on flash disk and qnx4.25 these days. I have one problem that
I want my system not to be corrupted when emergency power off…
However this behavior will be very often occrurred.
I have had the file system corrupted, so I want to get my system robust to
power down…
Please answer my question…
Ji, Sang Hoon <shji@iae.re.kr> wrote:
: Hi,
: I make system on flash disk and qnx4.25 these days. I have one problem that
: I want my system not to be corrupted when emergency power off…
: However this behavior will be very often occrurred.
: I have had the file system corrupted, so I want to get my system robust to
: power down…
: Please answer my question…
Sure thing.
You may want to adjust the cache size to a smaller value when
loading Fsys (-c option) the larger the number the more amount
of data that can be lost during a loss of power.
Of course adjusting this value from the default of 1/8 of your
system memory to a smaller value will result in slower disk
access.
Mike Shane
QA, QNX
mshane@qnx.com
Ensure you have the following line for each QNX Partition
early in your sysinit to correct any filesystem problems…
echo “Checking Disk Partition: /dev/hd0.0t77”
chkfsys -urqsP /dev/hd0.0t77
You could also get a UPS , write a process to detect the power fail,
and have that process execute:
system(“shutdown”);
Ji, Sang Hoon <shji@iae.re.kr> wrote in message
news:8rj76m$pbg$1@inn.qnx.com…
Hi,
I make system on flash disk and qnx4.25 these days. I have one problem
that
I want my system not to be corrupted when emergency power off…
However this behavior will be very often occrurred.
I have had the file system corrupted, so I want to get my system robust to
power down…
Please answer my question…
If the driver is using Fsys, then using a smaller than default
value for the -d option will also help. Of course this too
can degrade performance.
Previously, Michael Shane wrote in comp.os.qnx:
Ji, Sang Hoon <> shji@iae.re.kr> > wrote:
: Hi,
: I make system on flash disk and qnx4.25 these days. I have one problem that
: I want my system not to be corrupted when emergency power off…
: However this behavior will be very often occrurred.
: I have had the file system corrupted, so I want to get my system robust to
: power down…
: Please answer my question…Sure thing.
You may want to adjust the cache size to a smaller value when
loading Fsys (-c option) the larger the number the more amount
of data that can be lost during a loss of power.Of course adjusting this value from the default of 1/8 of your
system memory to a smaller value will result in slower disk
access.Mike Shane
QA, QNX
mshane@qnx.com
–
Mitchell Schoenbrun --------- maschoen@pobox.com
You may also want to consider an uninterruptible power supply -
Siemens makes a small battery backed 24V DC unit.