Raid 1 or Raid 5?

Toggle sidebar Toggle sidebar
ricehoshi

ricehoshi

Distinguished
Nov 9, 2007
63
0
18,630
I have ruled out RAID 0 and RAID 1+0 as possibilities for my new RAID setup, and am looking towards RAID 1 or RAID 5 for my new setup. For those that have had experience with both or either, which is more secure in terms of security and data loss probability especially with a single RAID setup which also exists for boot?

I assume that RAID 1 would be more secure since your drives are basically just clones of each other, but RAID 5 you can replace a failed drive and let it rebuild. Performance-wise it doesn't really matter to me, but I would like all my files in tact if anything goes wrong. Any light on this would be great.
 
Oh, also, how does this limit the storage space? RAID 1 with two 500GB drives would simply be 500GB, but RAID 5 with three 500GB drives? Would that make it 500GB as well or would it be something more like 750GB?
 
Well, raid actually just prevents disk failure, so, If you want to be safe from viruses, malware and such you just need a drive for backup, not raid, also backup will also safeguard your data in case of drive failure so thats two pros for backup (perhaps a NAS).
If you insist in raid go for Raid 1, it's less expensive and simpler.
 
Wait... I keep hearing people say that, but what do you mean not a substitute for backup? The only time I lose files is due to drive failure. I guess a virus would probably take me out, but I don't think having a network attached storage devise would be cost effective for me.

I have 3 drives each 250GB. What would give me the best capacity and security? Would I just have a drive on my computer dedicated to storage? Or is there some other way I am not thinking of? Thanks.
 
If you are looking for the best combination of speed, size and data security, then your are actually on the mark by choosing RAID 1+0 or RAID 5, whereas RAID 5 is probably the better choice. In either case you need a minimum of four (4) identical hard disk drives.

Like RAID 1+0, a RAID 5 configuration is a hybrid combination of data safekeeping as well as speed. But unlike the former, RAID 5 doesn’t rely on mirroring (e.g., RAID1 or RAID 1+0) to preserve your data and information. It instead uses an alternative method of data redundancy found in RAID setups, namely “Parity.” To get into the fine nuances of how parity works, would require a lengthy white paper. As a general rule, however, the mathematics of parity dictates that if you have four drives in an array, the RAID control will split each piece of data into three stripes. Each stripe will go to a single hard disk drive as it would in a RAID 0 configuration. The controller then creates a parity stripe based on the three stripes of data and adds it to the data stripe contents on each disk.

A parity stripe is a logical calculation that allows the controller to re-create any individual stripe that becomes corrupt (or in the case of a drive failure, nonexistent). So, if you are faced with such a failure (it’s actually not a question of IF, but WHEN), then similarly to mirroring, the lost data is made available to the host computer almost instantaneously.

Yet, the loss of a single drive puts the entire array at risk. This failure mode should be addressed immediately by replacing the defective drive. If Murphy’s Law should strike and an additional drive fails (e.g., two out of four drives giving up the ghost), then all data on the array will be lost.

Corollary: Parity stripe works really well, it just can’t perform miracles.

And, by the way, most external drives for data backup and archival storage contain multiple hard disk drives as well. For instance, a 1 TB external drive more often than not contains two 500 MB drives running under hardware implemented RAID 0 controls.
 
RAID 5 only requires 3 hard disk drives.

In any case, I guess my real question is if I plan on being secure and having two copies of my files (i.e. RAID 1) or would it be just as secure with the ability of having a rebuildable hard disk (i.e. RAID 5) or would I be better off just running two hard disk drives and having an idle drive in my build to just serve as a backup. If not RAID, what would be the best way to make sure that all files are in tact in the case of a hard disk failure?

NAS is out of the question for me, I don't have that kind of money to spend nor the space.
 
If you already have 3 250GB drives and can buy another, AND if you have an Intel board with an ICH8/9-R southbridge, you are in luck.

Do what I did:

Make 2 arrays out of your 4 drives. One is a RAID10 drive, put your OS on it. Turn the rest over to RAID5, put all your stuff there.

With just 3 drives, you need RAID5. If one drive fails, I suggest you replace it before using the array.
 
personally for home use - RAID1 has too high a cost, 1 drive for each one you RAID. RAID5 gets cheaper the more drives you add, with cappacity being # of drives in array - 1. Performance should also be better with RAID5.... moving to new hardware in the future would, in general be easier with the RAID1 setup unless you have a dedicated card for doing the RADI5.

Still backups are the best solution.... one good power surge and you could lose more than 1 drive and both RAID solutions are useless to you at that point...
 


Both are RAID, thus RAID 1 & RAID 5 will continue to operate with the loss of 1 drive and both arrays will need rebuilt once the failed drive is replaced.
 
RAID is not meant for the desktop. It only protects against drive failure, meaning it's for systems that need to keep running 24/7 even in the event of a drive failure. I've been running computers for 14 years now, and never once lost data to drive failure, but I can think of many instances where I lost it due to other random things. RAID is NOT a substitute for a backup, it is only for uptime.

RAID 5 without a dedicated controller is definitely not a good idea(poor I/O performance and will eat up your CPU cycles)

RAID 1 is not cost effective and I guarantee you will end up losing data one way or another if you use that as your only method of "backup" (virus, filesystem error, RAID controller going haywire(had that one before), power surge, etc)

In your case I would recommend one of the disks be your OS drive, one be a data/pagefile, and get a cheap hot swap backplane to pop that 3rd drive in for backups only, I forgot the model but there's a kingwin one for about $15 that works nicely.
 


If you don't care about performance, then you should just buy Acronis True Image 11 Home, setup the second drive as a backup partition, then setup Acronis to backup daily. Done.

If you don't stash every movie on the planet, and MP3 on your system, you should be able to backup months worth on the second drive.

If your backup drive dies, you buy another one, and start over. If your regular drive dies, you replace it and restore.

If you like to keep your downloaded installers, CD images for Linux, trial versions of games, or some other non-critical files, just get a third drive, and set it as your download location, but do not include it in your backups.

RAID has a lot of caveats for a home system. I use it regularly on servers, and my desktop, but I'm a software developer who spends way too much time and money on his computer efforts.

You also get the added benefit if you ever accidentally mess up your computer or lose your documents, you can at worst reinstall yesterday's backup, using the Acronis recovery CD. Additionally, your backups can be mounted as a temporary read only drive letter to pull files off a few at a time.

John
 
Answer to OP question is raid 5. It isn't inherently more or less secure than raid 1, but you get more capacity out of the system. Drives don't have to be identical, but the raid will only stripe to the size of the smallest drive. (2 300g and an 18g =36G raid 5)

Use a dedicated controller or (as many have said) you'll loose some processing power...somebodies gotta do the parity math, ya know?

I agree with jt001 though, raid just isn't designed for desktop use. I use raid on all my servers (work and home), and have built many desktops with raid subsystems in them - but only because I wasn't ready to throw the controller and drives away yet.

Raid provides a level of fault tolerance, not file security, etc. If your system gets infected/corrupted (or just plain stupid) raid won't help you. WHEN one of the drives fails, raid lets you put another drive in it's place and move on with your life.
 
Well, if I rule out RAID then since it is a desktop computer. What is the backup setup then if all 3 drives are hooked up internally? I mean, it is kind of inconvenient to be sticking in a harddrive to do a backup. I do have an external 250GB HD and a smaller 80GB HD as well that I am currently using for photo and image backups.
 
Well if I was going to do that I'd probably be just as secure (and get an edded performance value) if I went with RAID 0 and then backup the RAID to the third drive. Right?
 
I hate when people say RAID is not for the desktop. I know this is an enthusiast forum so most of you assume desktop = gaming rig. I have a computer for gaming and one for work (at home). RAID 1 has saved my butt more than once on my work computer which requires no down time. I also use Acronis to backup my array since we all know RAID is not a substitute for backups.

Also, those of you that say you don't need RAID because I've been using a computer for XX years and never had a drive fail... all I can say is you are fortunate. Some drives last longer than others, but they all fail eventually.

To the OP, if this is a gaming rig with no critical data, just get a secondary drive, internal or external, and use Acronis, Ghost, or your favorite backup software to backup your data up.
 
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom