RAID 1 or two seperate units

[bshphotography]

Hi all,

 

I am about to buy an external hard drive but I am not sure which one. Now, I am looking into 750GB up to 1 TB units.

I am buying exterrnal drives for first time and I do not have any experiense with them so any idea is welcome.

 

Which one is better one unit with RAID (at least 1TB, 1.5TB better) or 2 separate ones(750GB to 1TB each)?

 

I know that backing up to RAID is much easier, but is it safer? I want to move all my images to external drives so I

do not want to risk to much. Moreover I need an unit that would work on 110 and 240 VAC. My budget is about $400-

450

 

Thanks

[RobertChura]

I would use 2 separate drives. I had 2 drives crash at once one time and luckily I had another external drive .

[patricklavoie]

I know that backing up to RAID is much easier, but is it safer?.."

 

how? its the same as 1 drive if set to 0, and same as 2 drive if set to 1..its not more or less easy to backup on it.

 

The only thing is its more dangerous if you use them as raid 0, and for that you also need to backup this drive to another 1..so for that it look more complicated : )

 

I would use 2 big external drive personnaly, one to backp up the internal, one to backup the 1 external, and you bring this one with you or put it in a real safe place.

[mendel_leisk]

I also just rely on separate drives, and prefer *internal*, for speed and cost. I recently put a couple of fresh 500 gig drives in, to replace 250 gig drives. I keep the content of the two drives identical, via a small freeware command line utility. Only *one* of the old drives was apparently ailing (sometimes clicking). I opted to replace both: my (canadian) cost per drive was $72. These were Seagate Barracuda SATA2 7200 rpm.

 

Maybe ignorance is bliss, but I've never undertood the RAID concept, and seem to get on fine without it.

[brian_osterhout1]

If you are looking for safe storage, do not use RAID 0. RAID 0 is striping, and so files are split between the

two drives, so if one fails, you loose the data on both. RAID 0 is used to speed things up, not for backup.

RAID 1 is mirroring, so when you write to the volume identical information goes to both drives, so if one fails

then your data should be safe on the other drive. There are other, more exotic, RAID levels, but I doubt you'll

find them in consumer priced products. I have been successfully using the Dlink DNS-323. It is a NAS box

(connects to your computer via the network connection), which can be a bit slower than USB or firewire depending

on the speed of your network adapter, but it is easier to access from other computers. I have three places I

store files: my local hard drive, the NAS box, and DVD. I try to keep a file in at least two places at the same

time. So before I delete a file, I burn a DVD and copy it to the NAS box. Not very automated, but I feel better.

 

Depending on how concerned you are, you may also consider some scheme that stores a copy off site (at a a family

members or friend or safe deposit box)

 

Good luck!

[mendel_leisk]

So with RAID1, if you inadvertantly delete files from the first drive, they would be immediately deleted from the second drive?

[kelly_flanigan1]

RAID 1 is a mirrored system; both drives are mirrored and appear as one logical drive after bootup. <BR><BR>

[bshphotography]

wow Brian I like the idea of putting some of the file in a safe box :)

 

Ok , so is it possible to do RAID 1 (mirroring system) if I am using to separate drivers? Software?

 

I do not want to manualy copy/paste every new file 1st to one of the drives then to the other one because I may miss some. I know I should put more time probably in developing workflow rather than waiting a program to do it all by itself.

 

Thank you all your opinions really helped me

[brian_osterhout1]

Yep, the data is mirrored, so if you delete the file it is removed from both drives. When you set up a RAID 1 volume, you format it and it appears like a single volume ... just like the drive in your computer. But when data is written to (or removed from) the volume, it is sent to both drives. If one drive fails you should still be able to get to your data.

 

You can do RAID in the hardware via a RAID controller or in a separate device that does it for you like the DNS-323. Or you can do it in software. Depending on what operating system you are using you may be able to set up a RAID 1 volume without adding any software. Search the web and see what turns up.

[waltflanagan]

RAID stands for Redundant Array of Inexpensive Disks. Let's ignore RAID 0 since it decreases reliability. The point of RAID is that if one drive dies you don't have to spend an hour restoring your data from backups. A good RAID system automatically detects the drive failure and keeps on giving you the data from the other drive(s) It should also alert the user/sysadmin of a problem saying "drive #4 is dead" A high end RAID system is hot swappable, you remove dead drive #4 and replace it and the system automatically starts putting data on the new drive 4. Higher end RAID systems aren't a 1 for 1 copy but split the data up over 5 or more drives with parity information to reconstruct the data after a drive failure.

 

RAID is NOT a backup method to recover an accidentally deleted file. Delete a file and it's gone. The RAID system automatically deletes it from all of the drives. RAID is about having no downtime. Many businesses cannot afford to stop work for an hour or two when a drive dies while someone restores the data. RAID is about 24/7 uptime.

 

Backups should be done separately from RAID. Many NAS systems contain multiple drives and use RAID internally. Some also support "snapshots" which are automatic backups once a day or every hour etc. so if you accidentally delete a file you can find it in an earlier snapshot but even those are not full backups. The snapshots are usually configured to keep stuff back to a week or month but probably haven't been configured to keep 2 year old snapshots.

[bshphotography]

Thank you Walt and Brian , a lot of useful info

[pierre_c1]

I use a Linux PC with linux software RAID. So I have one RAID1 with 2x 250GB for the OS, and one RAID5 with 3x1TB for data storage. This gives 2.25TB total. It's about half full.

 

This linux box is very nice as a desktop too, to browse the web without getting virussed.

 

The windows PC is connected to this box via gigabit ethernet. While the RAID in the linux box reaches 200 MB/s, windows file sharing only reaches 60-70 MB/s but that's OK.

 

In the last years I lost a few harddisks, no data loss though.