Subject Re: [ib-support] When do FB/IB 'flush' to disk?
Author Phil Shrimpton
On Thursday 29 November 2001 23:20, you wrote:


> And I thought the discussion is about how to eat cake and have it,
> i.e. how to ensure that data are written to disk like with forced writes
> on, with actually setting forced writes off to increase speed.

I think it is very important that at some point data is written to the disk
files <g>

> > - I imported 200Mb of data in to a blank database
> > - Left the server and client app idle for 4 hours
> > - Pulled the power cord
> >
> > ...the database was blank after boot up
> Even if Windows flush data sooner than after 4 hours, there is still chance
> that you pull power cord right in the middle of write; if in that time
> pages written were reordered by OS, you get corrupted database. Period.

Pulling the power cord was an example (the server in question has UPS), my
main point is, is that Windows seams never to flush the data until you
disconnect, which in a 24/7 environment is a worry.

I am running a test at the momement, (with forced writes off), I have
inserted approx 1.5 GB into an empty database (and rising), and the GDB file
is still only 3MB (I know about the explorer display issue). If I pull the
cord, the database will be empty, but I am kepping the import going to see if
Windows will eventually flush the data, or something blows.


Linux 2.4.4-4GB
12:32am up 1 day, 7:22, 1 user, load average: 0.69, 0.38, 0.33