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Community/Discussion/QNX Momentics Community Support/OS corruption/List of Posts
Forum Topic - OS corruption: (4 Items)
   
Update
Lakshminarayanan R
06/29/2009 7:58 AM
post32687
OS corruption   
I have a QNX 4 file system in CF in a partition. While working with it, if abruptly power is removed, is there a chance 
for OS to get corrupted and thus the system is prevented from booting?
Jeevan Mathew(deleted)
06/29/2009 10:50 AM
post32731
Re: OS corruption   
> I have a QNX 4 file system in CF in a partition. While working with it, if 
> abruptly power is removed, is there a chance for OS to get corrupted and thus 
> the system is prevented from booting?
> 
> 


I wouldn't exclude this possibility.
Jeevan
Lakshminarayanan R
06/29/2009 11:03 AM
post32734
RE: OS corruption   
Is there a way by which this can be avoided so that I can use CF with QNX4 file sytem and can turn the power off 
abruptly even every single time??
________________________________________
From: Jeevan Mathew [community-noreply@qnx.com]
Sent: Monday, June 29, 2009 8:20 PM
To: momentics-community
Subject: Re: OS corruption

> I have a QNX 4 file system in CF in a partition. While working with it, if
> abruptly power is removed, is there a chance for OS to get corrupted and thus
> the system is prevented from booting?
>
>


I wouldn't exclude this possibility.
Jeevan


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QNX Momentics Community Support
http://community.qnx.com/sf/go/post32731
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Jeevan Mathew(deleted)
06/30/2009 3:06 AM
post32796
Re: RE: OS corruption   
> Is there a way by which this can be avoided so that I can use CF with QNX4 
> file sytem and can turn the power off abruptly even every single time??

If a write is occurring and the power is removed, corruption can happen.

There are some things that can be done to minimize the problem like:

mount filesytem read-only if/when possible (stops access time update)
open the files synch or use the "blk commit=high" option
umount the filesystem before the power is removed
decrease delayed write time with the "blk delwri" option
create a separate partition for writable files
do not put put writable files in the root directory
pre-grow files after creation
balance directory tree. ie limit directory levels and number of files
One other thing to note is that if power is removed during a write,
subsequent reads will fail until it is written.

Hope this helps.
Jeevan
For more info please post to the experts in the filesystem forum.

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