Raid 1 ?

24c · 21 Jul 2010

I want to set up 2 WD 640 GB spinners in a RAID 1 array for storage, my 1st attempt at a RAID 1 array. As I understand it, RAID 1 writes the same data to each HD, therefore creating 2 identical drives. 2X safety for files.

I am wondering:

1. could each drive be removed from the array and used separately?
2. if 1 fails, the other is still readable in the array?

My purpose for this is to have 2 copies of my files on separate drives for obvious safety reasons. I currently copy from one drive to another, not good if I forget to copy something and a drive fails.

ETA - title of post should be RAID 1 ?, not Raid i ?

I picked a heck of a month to give up coffee................

Kirsch · 21 Jul 2010

24c said:

1. could each drive be removed from the array and used separately?
2. if 1 fails, the other is still readable in the array?

1. Absolutely
2. There wouldn't be much use of RAID 1 if it wouldn't be, eh?

24c · 21 Jul 2010

Kirsch said:

24c said:

1. could each drive be removed from the array and used separately?
2. if 1 fails, the other is still readable in the array?

1. Absolutely
2. There wouldn't be much use of RAID 1 if it wouldn't be, eh?

Thanks, just checking. Sometimes I don't know what I think I know, and what I think I know is just plain wrong.

pparks1 · 21 Jul 2010

Keep in mind with RAID 1 that while you do have 2 copies of the data...in the event that you accidentally delete a file or get a virus and it corrupts a file that it's going to corrupt both copies of the file at the same time.

I prefer having data redundancy on an external hard drive that I can keep offsite. This way if somebody steals the computer or my house burns down...I don't lose my backup copy at the exact same time.

24c · 21 Jul 2010

@paprks1

I wanted to make the RAID 1 include 1 internal, 1 external drive, but I can't do that unless I get a real long SATA cable so I can connect the external drive to an internal SATA port. I think this correct anyway.

I do have an external drive case I'm using now, and after I get the RAID 1 set up, I may be able to copy to the external drive once a week or so for just such situations as you mentioned.

pparks1 · 21 Jul 2010

Sure, just wanted to make it clear that RAID was not a substitute for backup. So many people forget that and are left with a bad taste in their mouth when they lose their data and thought they were protected.

Kirsch · 21 Jul 2010

pparks1 said:

Sure, just wanted to make it clear that RAID was not a substitute for backup. So many people forget that and are left with a bad taste in their mouth when they lose their data and through they were protected.

Correct, and incorrect. I like your wording in your previous post.

It DOES backup against failed hard-drives (unless, obviously, both fail).

So.. RAID 1 can be considered a backup for faulty hardware.. how does that sound? :)

pparks1 · 21 Jul 2010

Kirsch said:

pparks1 said:

Sure, just wanted to make it clear that RAID was not a substitute for backup. So many people forget that and are left with a bad taste in their mouth when they lose their data and through they were protected.

Correct, and incorrect. I like your wording in your previous post.

It DOES backup against failed hard-drives (unless, obviously, both fail).

So.. RAID 1 can be considered a backup for faulty hardware.. how does that sound? :)

RAID is never a backup....it's redundancy....they are 2 different things. For example, get a virus on your machine. Then try to use your "backup" drive from your RAID set to see if things are fine.

RAID 1 is really necessary when uptime is critical. Suffice it to say that nothing in my home "has" to be up and operational. I can suffer from some downtime if my server crashes and I have to reload the OS. However, I cannot recover very easily if I don't have a backup of my data.

Kirsch · 21 Jul 2010

RAID 1 can be considered a backup against a faulty hard drive, that's all I am saying.

pparks1 · 21 Jul 2010

Kirsch said:

RAID 1 can be considered a backup against a faulty hard drive, that's all I am saying.

RAID 1 can save you in the 1 and only 1 instance that a hard drive fails. That is true. As a server admin for a living, I never utilize the terms RAID and backup to be interchangeable in any way. They are very different concepts. While you do understand this...other's don't.