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RAID question

PostPosted: Fri Apr 21, 2006 7:07 am
by chuckcrc
Hi
I have a question about setting up a RAID 1 Mirror array.
The pc that the family uses for the net, photos etc has a Sata1 80 gb drive in it that is connected to port 0 of the raid controller. This drive is not set up in any RAID array, it is just set up as a serial hard drive that the system boots from.

What I want to do is use this disk to combine with another identical disk to configure these into a RAID 1 array.

Can I do this without having to reformat the original disk. I don't want to lose all the data  photos etc on this disk.

I installed the second disk and rebooted the pc but it wouldn't boot correctly because it said it didn't know what device to boot from. It promted me to enter the RAID utility but when I tried to everything was greyed out.

Any ideas please ?

thanks
chuck

Re: RAID question

PostPosted: Fri Apr 21, 2006 9:48 am
by congo
You will lose your data if you create a raid array, you need a third disk to move the data to.

Re: RAID question

PostPosted: Fri Apr 21, 2006 12:15 pm
by NicksFXHouse
[quote]Hi
I have a question about setting up a RAID 1 Mirror array.
The pc that the family uses for the net, photos etc has a Sata1 80 gb drive in it that is connected to port 0 of the raid controller. This drive is not set up in any RAID array, it is just set up as a serial hard drive that the system boots from.

What I want to do is use this disk to combine with another identical disk to configure these into a RAID 1 array.

Can I do this without having to reformat the original disk. I don't want to lose all the data

Re: RAID question

PostPosted: Fri Apr 21, 2006 5:21 pm
by congo
And keep in mind that you've gotta use exactly the same disks : same capacity but same model from the same constructor too ;).



Are you sure about this or did you just make it up as you went along?

I believe what you said is the preferred configuration, as it will be more efficient, however, from everything I've read on the subject, RAID is not too fussy about what drives are in the array.

Re: RAID question

PostPosted: Fri Apr 21, 2006 5:24 pm
by chuckcrc
Thanks for the reply.
I will have to re think how I'm going to do this.

Do the disks have to be the same make and model ?

The original disk is a Seagate which I can't get another like it as they are out of stock/discontinued so I bought a Western Digitial Sata 1 drive of the same capacity. Will these work together?

thanks
chuck  

Re: RAID question

PostPosted: Fri Apr 21, 2006 5:25 pm
by legoalex2000
And keep in mind that you've gotta use exactly the same disks : same capacity but same model from the same constructor too ;).



thats not entirely true, im in the process of setting up a RAID 0 from a 30gb and a 40gb.

:)ramos

Re: RAID question

PostPosted: Fri Apr 21, 2006 5:28 pm
by congo
chuckcrc,

If they are both SATA drives I don't see a problem.

Not sure if you can mix ATA with SATA on a RAID controller, or which controller you need.

Re: RAID question

PostPosted: Fri Apr 21, 2006 9:40 pm
by NicksFXHouse
For maximum efficiency you want to use identical drives, capacity, manufacture, type and speed for RAID. It is not required but if you have 2 drives of different size and specification it will have negative influence on RAID performance.

Many RAID controllers will allow you to add a drive to the array in Windows, both SATA or IDE, however, doing that will usually remove the higher performance ability of the array. That type of hot-swap is not for RAID-0. It can be done in RAID-1, etc but even so, adding a slow ATA drive to an SATA array will pull performance down.

Re: RAID question

PostPosted: Sat Apr 22, 2006 3:44 am
by Politically Incorrect
My understanding is that if you were to set up a RAID on lets say a 30Gb and 80Gb drive, it would make the 80Gb drive a 30 Gb giving you 60Gb overall. So you would loose 50Gb.

Or in Ramos's case he would in the end he would have RAID on two 30Gb drives, loosing 10Gb.

I could be wrong about this but I think this is why it is recommneded to have two or more drives of the same capacity.

Re: RAID question

PostPosted: Sat Apr 22, 2006 4:02 am
by congo
Yes, that's correct, but if you already have the drives, why not?

The speed of the array is determined by the HDD with the lowest speed as well.

Using older drives in a raid 0 array must increase the risk of failure of the array due to the reduced reliability of older drives.

Re: RAID question

PostPosted: Mon Apr 24, 2006 9:42 pm
by chuckcrc
Well here are the results I got from setting up the Mirror array.

First I bought another 80Gb Sata hard drive which was not the same manufactuer as the original. The capacity was slightly more as well (original 78.50Gb . new 78.53Gb).
When I installed this into the PC and rebooted I said the system had an error message saying it didn't know what drive to boot from.
This turned out to be a setting on the new drive. The new drive I was told by the seller was a Sata 1. It was in fact a Sata 2- and the bios wouldn't detect it. I had to set a jumper between pins 5 & 6 to lock the drive into Sata 1 mode. (I only discovered this after I had bought another drive of the same manufactuer that had a label on the drive explaining what the jumper pins did.

Re: RAID question

PostPosted: Tue Apr 25, 2006 12:10 pm
by NicksFXHouse
[quote]Well here are the results I got from setting up the Mirror array.

First I bought another 80Gb Sata hard drive which was not the same manufactuer as the original. The capacity was slightly more as well (original 78.50Gb . new 78.53Gb).
When I installed this into the PC and rebooted I said the system had an error message saying it didn't know what drive to boot from.
This turned out to be a setting on the new drive. The new drive I was told by the seller was a Sata 1. It was in fact a Sata 2- and the bios wouldn't detect it. I had to set a jumper between pins 5 & 6 to lock the drive into Sata 1 mode. (I only discovered this after I had bought another drive of the same manufactuer that had a label on the drive explaining what the jumper pins did.