RAID mirroring question/frustration.

[mr tanooki]

So I am installing this $300 RAID card to mirror two HDDs.

The primary function of mirroring is to duplicate the data between two or more HDDs.

Shouldn't I be able to put one HDD with data in with another HDD without data, and let the RAID software 'rebuild' the blank HDD with the data from the other?

This RAID card does not offer that feature - It instead wants to wipe both of the disks.

1> Is it too much to say that a $300 RAID card should have this feature?

2> Is there a RAID card that DOES have this feature?

3> Or is there something that I am not understanding about how RAID mirroring works?

3.5> IS IT INHERENTLY IMPOSSIBLE FOR A RAID CARD TO DUPLICATE DATA FROM ONE DISK TO ANOTHER BEFORE BUILDING THE ARRAY? IF SO, WHY?

Advanced thanks for your input. PLEASE ANSWER THE QUESTIONS AND DON'T MAKE SILLY ASSUMPTIONS ABOUT ME OR WHAT I NEED TO DO.

 

[Dangman]

1) Yes
2) No
3) Yes. As far as I know, all RAID cards and integrated solutions will wipe out the data during the initial building of the array. However once the RAID setup is completed and if the card supports OCE (Online Capacity Expansion), then you can expand the size of the array without losing the data or reformating.

So, backup the data somewhere else, setup and build the array, and then move the data back onto the array. Though for a RAID1 setup, which I think you're trying to go for), a $300 RAID card was overkill. Most mobo's onboard RAID chips are enough for a RAID1 setup. However if you want a RAID5 setup, you might want to get a third drive and added it in from the get-go. AFAIK, you can't go from RAID1 to RAID5 on many RAID cards out there.

 

[mr tanooki]

1) Yes
As far as I know, all RAID cards and integrated solutions will wipe out the data during the initial building of the array. However once the RAID setup is completed and if the card supports OCE (Online Capacity Expansion), then you can expand the size of the array without losing the data or reformating.

This does not explain why it cannot be done. You merely say that all other cards are set up the same.

So, backup the data somewhere else, setup and build the array, and then move the data back onto the array. Though for a RAID1 setup, which I think you're trying to go for), a $300 RAID card was overkill. Most mobo's onboard RAID chips are enough for a RAID1 setup. However if you want a RAID5 setup, you might want to get a third drive and added it in from the get-go. AFAIK, you can't go from RAID1 to RAID5 on many RAID cards out there.

I did not need an explanation on how to set up the RAID. $300 dollars is not overkill for a RAID card that is going into a large business server. I did not need information about RAID 5.

 

[MaStaFLaSH]

lol you don't know how raid works. Don't thumb down Danny's post he gives all the right data. When you build a new raid array it always wipes the data. That's how it works period.

 

[mr tanooki]

lol you don't know how raid works.

You have made an accusation (based on a false assumption - presumably that I am frustrated that I cannot get the RAID working) in an attempt to mock me. This is known as 'flaming' and is not allowed on this forum. Please read http://www.hardforum.com/showthread.php?t=760666 rule number one and don't do it again.

Don't thumb down Danny's post he gives all the right data.

Please read my prior post.

When you build a new raid array it always wipes the data. That's how it works period.

Your post contributed nothing to the thread and answered no questions.

 

[MaStaFLaSH]

 

[maven]

I haven't looked at the various available RAID cards, but in general the RAID controller requires certain addresses on each disk to be free where it writes information regarding, status, number of disks in the array, etc.

 

[Lazn_Work]

I haven't looked at the various available RAID cards, but in general the RAID controller requires certain addresses on each disk to be free where it writes information regarding, status, number of disks in the array, etc.

And we have a winner.. The RAID card needs to be in control of the Data because it will use some of it for it's own purpose (partition marking, RAID configuration, etc).. Thus it can't integrate existing data because those sectors (think boot sector on stand alone disk) might be used by your existing data.

This usually isn't a big deal, because most people don't install their OS before buying all their hardware.

What you want to do should be possible with Software RAID.. If you are in windows, convert the disk to dynamic, add the 2nd drive, mirror it, wait for it to finish replicating, then you can remove the 2nd drive and replace it, rebuild etc and end up with bunch of copies of that drive.

However I'd just use Acronis or some other drive imaging software to do this.

 

[mr tanooki]

I haven't looked at the various available RAID cards, but in general the RAID controller requires certain addresses on each disk to be free where it writes information regarding, status, number of disks in the array, etc.

That makes a great deal of sense. Thank you very much!

 

[mr tanooki]

This usually isn't a big deal, because most people don't install their OS before buying all their hardware.

What you want to do should be possible with Software RAID.. If you are in windows, convert the disk to dynamic, add the 2nd drive, mirror it, wait for it to finish replicating, then you can remove the 2nd drive and replace it, rebuild etc and end up with bunch of copies of that drive.

However I'd just use Acronis or some other drive imaging software to do this.

I did not need any of this information. Please reread my original post.

Since many of you have made the assumption that I had difficulty setting up this RAID array I will tell you what I did (well before I even started the thread):

I simply set up the empty RAID array and cloned the original disk over.

Thanks to maven for responding with the answer to my question.

 

[alamone]

Actually, if you used the bog standard ICH that comes with every motherboard these days, the Intel Matrix Storage Manager lets you create a mirror out of an existing JBOD disk, I think even the system disk. However, I don't trust the ICH very much to my data so I wouldn't suggest it.

So yes, most hardware raid cards need to initialize your raid, and you can't just convert a JBOD into a RAID1. There needs to be some space for the RAID metadata, which isnt reserved in a JBOD.

 

[Lazn_Work]

I did not need any of this information. Please reread my original post.

Please to realize this is the internet, and you don't own this thread.

You have been quite rude in this post when people were just trying to help just because you didn't like their tone of voice, or that they posted info that you "already knew" how are they to know what you know?? We can't read your mind, and it's best to start with basic help first rather than assume a high level problem.. (eg: check your power cord first)

 

[DonDon]

Hey Dudes, settle down.

If a person appears to be rude in a Forum response, it is best to ignore them. Many times one person being rude is another person being terse. I personally think the first response, while a bit more to the point than I am, was perfectly appropriate for the information given. Trying to get in their face and challenge them will just start a flame war, and the Thread will die a quick death without the original question being answered.

OP, please, take a deep breath, and please do not be so quick to get on someone who was only trying to help. A simple, " could you go into more detail about that?" may have gotten a much better response. [H]ardOCP and the [H]ardForums takes pride in showing a little irreverence at times. Please do not take it personal. We are all (mostly) friends here.

Don

 

[mr tanooki]

Please to realize this is the internet, and you don't own this thread.

You have been quite rude in this post when people were just trying to help just because you didn't like their tone of voice, or that they posted info that you "already knew" how are they to know what you know?? We can't read your mind, and it's best to start with basic help first rather than assume a high level problem.. (eg: check your power cord first)

ha ha ha