[dba-Tech] Petulant PC

Arthur,

Just go for it.  For about $500 you can get a dedicated raid controller that
will handle 8 SATA 2 hard drives.  

http://www.newegg.com/Product/Product.aspx?Item=N82E16816131004


You can now purchase 750g hard drives for ~$240.

http://www.newegg.com/Product/Product.aspx?Item=N82E16822148134

So for somewhere in the neighborhood of $750 you have the start of a kickass
raid system. That is EXPANDABLE.


Now add two more of these same drives in a few months.  Dedicate one to the
RAID5 redundancy, and another to data storage.  Now any disk can fail
without endangering your data.

A few months later add another, and another and another.  Eventually
dedicate another drive to raid 6.  You now have a raid array where any TWO
disks can fail without endangering your data.

You can end up with 6 x 700 (real) or 4.2 terabytes of raid 6 storage.  That
should handle your issues with saving your backed up images for quite awhile
I would think.

BTW, that controller card is wicked fast, real life read data streaming of
>400 mbyte / second when fully implemented.  Reads can stream data off of
all available drives so the read speed is cumulative, as you add more disks,
the streaming read rises.  Writes OTOH are at slightly less than a single
drive.  This kind of performance is great for a data warehouse kind of
system where data rarely changes.

I have two of these systems.  One has 8x 320 drives (300 real) in Raid 6
with 6 of those drives actually available for storage.  I went with 320s for
the first set because at that time (about a year ago) that was the sweet
spot.

The second one I am still building out.  It currently has 6x 500gb drives
(~470 real) in raid 5 with 5 drives available for storage, and when I add
the final two drives one will go to raid 6 and the other for storage so I
will have 6 x 470g of storage.    ATM 500g is the sweet spot, but the 750g
drives are dropping like a rock so they will hit the sweet spot within a few
months I think.

The second system I actually built from the ground up using the raid
controller such that it actually boots off the raid, with a 200 gb partition
for the boot disk.  The rest of the space is available for storage

This fall I will probably build a system with two quad core processors on a
single motherboard, and for that system I will build out a raid system
around the 750gb disks, booting off the raid array like I do with the second
system I built.

Yes, I know that it is not cheap to get in to, but the redundancy is great
peace of mind, and it is expandable so that you can do it a piece at a time.
The nice thing about a dedicated controller is that it is portable.  If the
system fails, the whole shootin match can just be dropped into another
system.  With a raid based on a motherboard, this won't work unless you get
another of the exact same board.

John W. Colby
Colby Consulting
www.ColbyConsulting.com 
-----Original Message-----
From: dba-tech-bounces at databaseadvisors.com
[mailto:dba-tech-bounces at databaseadvisors.com] On Behalf Of Arthur Fuller
Sent: Sunday, June 03, 2007 4:40 PM
To: Discussion of Hardware and Software issues
Subject: Re: [dba-Tech] Petulant PC

The following is no help at all to your current situation, but since you
have used Ghost for a while, and I never have, even though I had it included
in a previous version of Norton, I thought I would ask:

Let's say your current boot drive has 250GB capacity and 150GB is occupied
when you Ghost. How big is the Ghost file? Do you need another HD upon which
to plant said file?

The reason I ask is this: a bare-bones installation already comes with my HP
computer. (This is achieved by partititioning the HD, creating a read-only
partition with the initial image on it, then allowing you to start over
anytme by re-initializing drive c: from the r-o drive d:. However, even
though I love this ability, it still means after re-initializing I have to
spend the better part of a day reinstalling Office, Office Developer,
SP1...n, NoteTab, winRAR, VS.NET, SQL 2005 and so on. So even though I can
reinit the original, I still lose a day implanting the rest.

So let's assume that the total install that satisfies me is > 50% of the
disk. Does Ghost compress it? Even if it does, I think there is no
alternative but a pair of disks of whatever size in the machine of interest.
Ok. Given that if I'm talking about a box with a 500GB disk, therefore I
need a pair, in fact three (the third on another box, so I can copy the
Ghost file to safety).

This sounds:
a) like a recursive problem;
b) reminiscent of the days of FastBack, when I needed 50 3.5 disks to back
up my HD (currently the number of dual-layer DVDs is smaller, let's see
250GB / 4.7 GB = 50 + single-layer DVDs. That assumes the drive is full. I
never let a drive get even 50% before I think it's time for another.
Fortunately prices plummet in relatively direct proportion with my
compulsive need to install more software and create new data.

Either way, it seems that backup has been momentarily possible and then
suddenly impossible, then possible, then impossible, then possible, then
impossible (repeat until exhausted). Hofstadter, so to speak.

Even the alleged massive storage of Blue-Ray apparently leaves us in the
FastBack situation of multiple disks. 200GB to back up, 50GB on a Blue-Ray.
Back in the FastBack situation. If disk 3 has a problem, I have a BIG
problem.

A.