Re: hard drive fry and upcoming show, and APIS!!!

From: Michael Koch-Schulte ^lt;[email protected]>
Date: 07/04/05-02:39:29 PM Z
Message-id: <003001c580d8$7a4bb3c0$a600a8c0@Sweetwood>

Don Bryant wrote:
> Michael,
>
>> It also increases
>> the
>> "read" performance of the system overall, things tend to load super
>> fast because the computer can read data "across" the drives.
>
> A Raid 1 configuration has the same read time as a single drive. It
> is the writes that take longer since the second drive is being
> mirrored.
>
> With a Raid 0 configuration multiple physical drives are striped to
> present 1 (or more) logical drives to the OS. When reads occur on a
> Raid 0 configured drive (logical) then there is the possibility that
> data will be fetched from more than one drive which will result in
> longer read times. Raid 0 configurations can use multiple drives of
> different sizes. Raid 1 requires identical drives for mirroring where
> Raid 0 can use different sized drives of different specs as long as
> the drives are compatible with the drive controller.
>
> Just my 2 cents to clarify,
>
> Don Bryant

Actually not quite. Overall RAID 1 reads are generally significantly faster
than single drives because modern controllers can assign a second read task
to the second drive. Writes are on par or insignificantly less than single
drives. RAID 0 (a favourite with gamers and video editors) if done correctly
using drives with identical geometry, sees a significant overall performance
increase for both reads and writes, but you don't get any fault tolerance,
one drive goes and you're fishing around looking for your back up tapes.
Mileage may vary with onboard RAID motherboards true, but for the most part
you never see a performance decrease only increases with both RAID 1 and 0.
If you want to get serious with RAID use a dedicated card from a company
like Promise or Adaptec. In the end harddrives are like lightbulbs, when
they decide it's time to go there's not much you can do about it so you'd
better have a plan and that's what this thread is about. RAID 1 isn't a
substitute for doing backups, it isn't going to protect you from viruses or
lightning strikes but it does buy you "up time". It gives you precious
moments to keep working or the extra time needed get files off your system
while waiting for the new drive to arrive. All that for a $100 -- a bargain
in my books.

~m
Received on Mon Jul 4 14:40:15 2005

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