----- Original Message -----
From: "Lester Caine" <lester@...>
To: <firebird-support@yahoogroups.com>
Sent: Sunday, March 14, 2004 10:38 PM
Subject: Re: [firebird-support] Embedded server database easily corrupted


> Da Jiao wrote:
>
> >>Having had fun in the past with power out problems, even
> >>before switching to Interbase, I can say it is not an easy
> >>problem to solve in software. Some sort of UPS is a must to
> >>ensure that power-outs can be managed.
> >
> > But this application is a small one running on ordinary customers'
desktops.
> > Cannot force them to use UPS.
>
> Always a problem area, which is why I always save the
> important data on a separate network machine. You never know
> what an 'ordinary customer' will do on theirs.
>
> >>You do not say, but for windows we had great fun at one time
> >>when a whole days work could be lost, simply because the OS
> >>was caching the information and totally ignoring the flush
> >>to disk!
> >
> > IB or FB?
>
> This predates my use of IB. Early 1990's we were running
> dBase and Codebase. It took a year, but we got the desktop
> software to the point that you could unplug the machine,
> plug it in again, and carry on (W3.1 and W98SE). WINDOWS
> 2k/XP fails that test today, which is the first problem!
>
> >>Things are a little better now, but since vital information
> >>may well be held in RAM, and not get copied to disk
> >>corruption's are difficult to avoid if you simply switch of
> >>the power.
> >>There are a few cache settings that will make things better,
> >
> > What are them, please give details.
>
> The obvious one is 'Forced Writes' ON in the database. (
> That is one that the earlier Windows caching used to ignore :) )
>
> Make sure windows is set 'Optimized for Background
> Services', that way the 'server threads' will be completed
> faster. ( Anyone - Does that apply with embedded - it does
> affect SuperServer I believe )
>
> Switch any 'Write Cache' off on the disk drive or disk
> server ( Hardware settings - this will ensure that essential
> pages are not sitting in the hardware cache when the power
> goes out )
>
> As I say, it has been a while since I've worried about any
> of this. My customers tend to accept that the starting point
> is a UPS now.
>
> --
> Lester Caine
> -----------------------------
> L.S.Caine Electronic Services
>
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