Thanks nige !

so it's mean that my single file (the .gbd) will be split across all the hard drive in raid0

But (speaking about read) is it not the same for RAID 1 ?
my data will be share across 2 disks, so to read it i can read simultaneous in the disk 1 and in the disk 2 ? for write off course it's will be more slower than raid 0 ?

also when we read the file, we read it mostly sequentially, bytes by bytes, so doesn't really matter how many disk they are... no ?

thanks for all
stephane

--- In firebird-support@yahoogroups.com, "Nigel Weeks" <nweeks@...> wrote:
>
> Raid 0 is called striping. The '0' means it provides no redundancy or fault
> tolerance.
>
> It divides the filesystem and files into blocks that you define when
> building the array, and then stores those blocks on consecutive hard drives.
>
> Thusly, if you stored your 20GB file on a single SATA100 drive, you will get
> a theoretical speed of 100MB/s data throughput
>
>
>
> Now, if you use RAID0 across multiple drives, say 6 * SATA100, and depending
> on the interconnect you use (PCI, PCI-X, PCI-EX, PCI-EX4, PCI-EX8) you can
> then get speeds nearing the throughput of your interconnect / bus system.
> This is because you essentially multiply the speed of each device by the
> number of devices you have (6 * 100MB/s = 600MB/s).
>
> Naturally, having 50 SATA drives hanging off one PCI slot will only get you
> ~160MB/s, as that's the limit of the old style PCI bus.
>
>
>
> Here's one comparison of Interconnect methods
>
> http://www.computerworld.com/computerworld/records/images/chart/pci_pcix.gif
>
>
>
> There may be inaccuracies in the above posting - I haven't had coffee yet...
>
>
>
> Nige.
>
>
>
>
>
> From: firebird-support@yahoogroups.com
> [mailto:firebird-support@yahoogroups.com] On Behalf Of svanderclock
> Sent: Wednesday, 18 November 2009 8:36 AM
> To: firebird-support@yahoogroups.com
> Subject: [firebird-support] Re: Raid 0 or not ?
>
>
>
>
>
> I know but we are only looking for performance !
>
> For a Database of 20 GB, regarding the speed, is it better to use RAID 0 or
> not ? I read that read 0 is twice more faster BUT is it true when we speak
> about only one file (the .GDB) ?
>
> Thanks you by advance
> stephane
>
> --- In firebird-support@yahoogroups.com
> <mailto:firebird-support%40yahoogroups.com> , "Anderson Farias"
> <peixedragao@> wrote:
> >
> > Hi,
> >
> > |For a Database of 20 GB, regarding the speed, is it better to use RAID 0
> or
> > not ? I read that read 0 is twice more faster BUT is
> > |it true when we speak about only one file (the .GDB) ?
> >
> > I wouldn't use RAID 0 !! It would not be safe for your Database.
> >
> > RAID 1 is simple (cheap), safe and will also improve speed for your reads.
>
> > I've been using it with great results.
> >
> > Also, If you can afford and need something even more "secure" than you may
>
> > want to try RAID 10.
> >
> >
> > Regards,
> > Anderson
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>