db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mike Matrigali <mikem_...@sbcglobal.net>
Subject Re: Any problems to run derby in USB drive ?
Date Tue, 10 Jul 2007 18:38:50 GMT
This leads me to believe that these drives are not correctly supporting
sync to disk as required by derby.  Derby uses java to sync the data and
log files when necessary.  If the devices don't correctly respond to
these requests then a number of different types of corruption:
checksum errors
mismatched index/base tables because log and data syncing not correctly 

My guess is that device driver for the usb device responds to a write
sync immediately before actually forcing the data to the device.  This
is similar to the problem of setting "write cache enabled" on windows.
Derby can not guarantee a consistent database under these conditions.


Francois Orsini wrote:
> Ivan,
> If you decide to run your application from an USB drive, try to make 
> sure it is *unmount'ed* (on Unix) or software-safely removed on Windows 
> properly, to ensure all data has been flushed to the USB drive. I have 
> seen file checksum/corruption issues occasionally where removing a drive 
> right after completing writes on it...Maybe something you can test as 
> part of your application and on the targeted platforms.
> --francois
> On 7/6/07, *Ivan Ooi* <olibralo@gmail.com <mailto:olibralo@gmail.com>> 
> wrote:
>     Hi all,
>        I wanted to deploy my App with Derby in USB drive but I'm not
>     sure is there any restrictions or not ? or problems ?
>     Thanks

View raw message