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View Full Version : Setting up Raid as easy as 1,2,3?




eosman
Nov 21, 2008, 01:30 PM
I'm thinking about getting a Mac Pro tower from apple, and then buying two 500gb hard drives to place them in a raid 0 config. My question is, is setting up raid as easy as taking out the existing hard drive, placing both the new drives into the mac pro, and selecting raid 0 from OSX when I reinstall the operating system?? Or does the Mac have something similar to a Bios setup where I select that?



andrewag
Nov 21, 2008, 06:18 PM
If you're after a software based solution, it's all done in Disk Utility. If you get the Apple hardware solution you use RAID utility.

nanofrog
Nov 21, 2008, 07:56 PM
I'm thinking about getting a Mac Pro tower from apple, and then buying two 500gb hard drives to place them in a raid 0 config. My question is, is setting up raid as easy as taking out the existing hard drive, placing both the new drives into the mac pro, and selecting raid 0 from OSX when I reinstall the operating system?? Or does the Mac have something similar to a Bios setup where I select that?
RAID in general can have it's challenges, but it shouldn't be too bad. :)
I'll presume you are aware of the dangers of RAID 0, and don't have a problem with using it. :D
If you're after a software based solution, it's all done in Disk Utility. If you get the Apple hardware solution you use RAID utility.
I wouldn't ever use Apple's RAID card. Too expensive, slow, there's issues with the battery, and it can't handle multiple OS's.

Just a bad idea. Other solutions exist, that have various advantages, depending on specific needs. ;)

scottlinux
Nov 22, 2008, 02:09 PM
RAID 0 sees no significant performance increase unless you are using a pair of 10,000 rpm drives, IMO.

Lots of people these days are doing a three drive setup:

1 drive: OS drive
2 drives: in RAID 1 for documents, data, etc.

That way, all data and documents are redundant. And performance is pretty good as the OS drive is separate.

YMMV :cool:

Semiopaque
Nov 22, 2008, 03:33 PM
RAID 0 sees no significant performance increase unless you are using a pair of 10,000 rpm drives, IMO.

Lots of people these days are doing a three drive setup:

1 drive: OS drive
2 drives: in RAID 1 for documents, data, etc.

That way, all data and documents are redundant. And performance is pretty good as the OS drive is separate.

YMMV :cool:

With 3 striped drives I see some noticeable performance increases, however, they are minimal for most things and I'm not sure it's really worth it for me at the moment. I'm probably going to drop my current 3 disk setup and go with something similar to what you mentioned:

1st drive : OS and apps
2nd and 3rd drives: 2 partitions on each, partition 1 in a striped set for scratch and second partitions mirrored for data.

Will see if I notice any real difference in that setup at all.

nanofrog
Nov 22, 2008, 08:44 PM
With 3 striped drives I see some noticeable performance increases, however, they are minimal for most things and I'm not sure it's really worth it for me at the moment. I'm probably going to drop my current 3 disk setup and go with something similar to what you mentioned:

1st drive : OS and apps
2nd and 3rd drives: 2 partitions on each, partition 1 in a striped set for scratch and second partitions mirrored for data.

Will see if I notice any real difference in that setup at all.
Are you running software RAID?

Semiopaque
Nov 22, 2008, 11:25 PM
Are you running software RAID?

Yep.

m1stake
Nov 23, 2008, 01:16 AM
RAID 0 sees no significant performance increase unless you are using a pair of 10,000 rpm drives, IMO.

My boot times are about the same, but my write has REALLY improved.

Are you running software RAID?

Why do people run soft raid? I just don't understand it at all. Saying it undermines the performance gain is a hyperbole, but it's just a silly thing to do when far better hardware solutions exist.

Semiopaque
Nov 23, 2008, 01:37 AM
My boot times are about the same, but my write has REALLY improved.



Why do people run soft raid? I just don't understand it at all. Saying it undermines the performance gain is a hyperbole, but it's just a silly thing to do when far better hardware solutions exist.

Additional hardware costs more. The software RAID is free.

I won't argue the fact that hardware RAID is definitely better, or even the fact that software RAID detracts from potential overall performance, however, if you are not utilizing all your processing resources anyhow, I'm not sure it hurts. I can only speak from what I have observed, so no hard facts really, but I will probably try some tests before I pull this RAID down at some point in the near future and compare it to how things work w/o it.

m1stake
Nov 23, 2008, 09:04 AM
Good point - can't complain about free :p

nanofrog
Nov 23, 2008, 10:19 AM
My boot times are about the same, but my write has REALLY improved.

Why do people run soft raid? I just don't understand it at all. Saying it undermines the performance gain is a hyperbole, but it's just a silly thing to do when far better hardware solutions exist.
I've observed much better performance using hardware based solutions. They do a little more IMO than just reduce the load on the CPU/s with the additional features. Cache helps the speed immensely, and of course the additional RAID types. ;)

But the FREE aspect of software RAID is difficult to turn down for many it seems. :p And I can't blame anyone for that one. ;)
Additional hardware costs more. The software RAID is free.

I won't argue the fact that hardware RAID is definitely better, or even the fact that software RAID detracts from potential overall performance, however, if you are not utilizing all your processing resources anyhow, I'm not sure it hurts. I can only speak from what I have observed, so no hard facts really, but I will probably try some tests before I pull this RAID down at some point in the near future and compare it to how things work w/o it.
In general, your assumptions are correct. :) But the additional capabilities do make a difference in my experience. There is certainly the built-in cache, and RAID types, but there's also other things. For example one I like is the backup copy of the partition tables stored on the RAID card. It can make life much easier if something goes wrong. There's a few others, but it all comes down to specific needs. Some cards (less expensive) will eliminate some of the advanced features, and others (more expensive ~$800+) throw in everything but the kitchen sink. :p

supajay
Nov 23, 2008, 06:26 PM
Ok... so i recently bought a mac pro from someone second hand and i'm thinking of putting some new disks in it.

I'dd love to do it
disk 1 = os + aps
disk 2 + 3 = raid 1 data (mainly itunes)
disk 4 = scratch for logic and such


My question is... When disk 2 or 3 fails, can you read the other disk without any problems or does it need to build up first? I had an external raid enclosure of iomega and when one of the disks fell out. I could use it externally, but i couldn't pop the hd it in the mac for reading of it. But seeing as we are allready in the mac pro, the are just formatted both in hfs or something like that?

belvdr
Nov 23, 2008, 06:39 PM
RAID 1 means both disks have the same copy of the data. So, if one of those disks fails, you can still read the data. Of course, if that second drive fails, you're toast, but I figured you knew that.

I'm guessing that external closure was doing something proprietary, or the array controller handling those disks refused to do things the normal way.

supajay
Nov 23, 2008, 07:10 PM
Ok... i understand that one.

But say, i pull the remaning (working) drive out of the mac pro. Will it just be readable in another mac pro? Will it show as a regular drive? That's what i'm the most curious about actually.

belvdr
Nov 23, 2008, 07:26 PM
Ok... i understand that one.

But say, i pull the remaning (working) drive out of the mac pro. Will it just be readable in another mac pro? Will it show as a regular drive? That's what i'm the most curious about actually.

I think it should. It may have headers on the disk saying it is part of a mirror, but I see no reason why it shouldn't be readable.

Munix88
Nov 24, 2008, 03:47 AM
@eosman:

I recently just did something like what you're talking about and it really is quite easy. First I booted up on the default drive to make sure it worked of course. Then just install the drives (with the comp off obviously) and hold down the C key after the *booong* start-up sound and it will start into where you can select Disk Utilities. I erased my old drive to get rid of the Leopard install then added the new drives to a soft-RAID 0, this together took only a few minutes at most. Finally I installed Leopard to the newly RAIDed drives.

Don't worry about the order the drives are in Disk Util because I noticed after booting several times to it they show up in different orders so I guess it just depends on when it detects them.

thereur
Nov 24, 2008, 12:40 PM
Would it be preferable to set up software RAID 1, or to use a backup utility? Assuming the only goal is to create a backup.

m1stake
Nov 24, 2008, 01:17 PM
RAID1 > backups. Why take time to back something up or have time machine do it once an hour when a raid1 array can back up your data as you create it?

belvdr
Nov 24, 2008, 01:18 PM
RAID1 > backups. Why take time to back something up or have time machine do it once an hour when a raid1 array can back up your data as you create it?

Because if a mistake happens (no pun intended), and someone deletes a file, it is gone off both drives and not easily recoverable, whereas you could recover with a backup. RAID 1 is meant to cover you from disk failure. Backups are meant to cover you from data loss.

Thus, backups > RAID of any type.

Semiopaque
Nov 24, 2008, 02:30 PM
Because if a mistake happens (no pun intended), and someone deletes a file, it is gone off both drives and not easily recoverable, whereas you could recover with a backup. RAID 1 is meant to cover you from disk failure. Backups are meant to cover you from data loss.

Thus, backups > RAID of any type.

Ideally, you would want a mirrored RAID with another utility backup solution. Can get a bit expensive, though. I forgo the mirroring and just use SuperDuper to clone certain partitions once I get to a point where I'm afraid to lose any of the data on those. That could also be automated with software as well, though, depending on how it is set-up, you could find yourself in the same situation as listed above - you clone a partition that you deleted something from unintentionally and now it's gone on both current disk and backup.

I'm pretty scared of losing some of my data so I have one drive with initial data and a cloned drive of same data. The cloned drive is only attached to my PC when performing cloning - otherwise it is in an antistatic bag in a plastic case in a locked box (I may get a fireproof, waterproof safe for it at some point - yeah I'm paranoid).

I'm not as scared of losing my system info because I could always reinstall, but I have a few different OS partition clones (including an old Tiger clone) just in case I need to go back for some reason. That drive fills my fourth slot in my MacPro.

m1stake
Nov 24, 2008, 02:46 PM
Because if a mistake happens (no pun intended), and someone deletes a file, it is gone off both drives and not easily recoverable, whereas you could recover with a backup. RAID 1 is meant to cover you from disk failure. Backups are meant to cover you from data loss.

Thus, backups > RAID of any type.

It's not as if whatever you delete is actually gone. But you're right, a mirrored array and a regular backup disk is simpler.

I'm pretty scared of losing some of my data so I have one drive with initial data and a cloned drive of same data. The cloned drive is only attached to my PC when performing cloning - otherwise it is in an antistatic bag in a plastic case in a locked box (I may get a fireproof, waterproof safe for it at some point - yeah I'm paranoid).

LOL

One computer, with 4 internal drives in RAID1, 12 time capsule wireless backups, and 25 generic external hard drives. THERE'S YOUR REDUNDANCY.

Semiopaque
Nov 24, 2008, 02:57 PM
One computer, with 4 internal drives in RAID1, 12 time capsule wireless backups, and 25 generic external hard drives. THERE'S YOUR REDUNDANCY.

Hehe. Need to add some offsite backup too. For only $24,000/month I could protect my 4TBs here. http://www.usdatatrust.com/service/pricing.asp :eek:

nanofrog
Nov 24, 2008, 03:52 PM
It's not as if whatever you delete is actually gone. But you're right, a mirrored array and a regular backup disk is simpler.
Assuming you have RAID, loose the Partition Tables, and see what happens. :eek: You learn really quickly the PITA backups are really needed. ;) :p

One computer, with 4 internal drives in RAID1, 12 time capsule wireless backups, and 25 generic external hard drives. THERE'S YOUR REDUNDANCY.
Not enough! :eek: :D
Hehe. Need to add some offsite backup too. For only $24,000/month I could protect my 4TBs here. http://www.usdatatrust.com/service/pricing.asp :eek:
And the truly paranoid use multiple off site backup locations (3+) just in case the other two burned down, fell into a volcano,... :D :p

m1stake
Nov 24, 2008, 06:46 PM
What happens when the earth is destroyed by meteors? How dumb would you have to be to keep all your backups on earth? Pretty dumb, that's how dumb.

nanofrog
Nov 25, 2008, 12:20 AM
What happens when the earth is destroyed by meteors? How dumb would you have to be to keep all your backups on earth? Pretty dumb, that's how dumb.
True. :D
But what options do we actually have ATM?
C'mon NASA, our computers need planetary colonization for backups. NOW! :p

Semiopaque
Nov 25, 2008, 01:08 AM
True. :D
But what options do we actually have ATM?
C'mon NASA, our computers need planetary colonization for backups. NOW! :p

I am working on a product that offers extraterrestrial backup storage solutions on the habitable planet of your choice. Due to the nature of the product, however, your data will only be recoverable in the event of an cataclysmic, planetary disaster (1). For an additional fee, we will name that planet after you and register that name with the U.S. Coyright Office (2).

1)Cataclysmic, planetary disaster is defined as an event which destroys all lifeforms on the planet.2)Your planetary name will not be recognized by the scientific community, or by anyone for that matter, and no one will care.

PS Where's the OP? I think we're getting a little far from the topic. :p

nanofrog
Nov 25, 2008, 10:31 PM
I am working on a product that offers extraterrestrial backup storage solutions on the habitable planet of your choice. Due to the nature of the product, however, your data will only be recoverable in the event of an cataclysmic, planetary disaster (1). For an additional fee, we will name that planet after you and register that name with the U.S. Coyright Office (2).
LOL! :D
Taking marketing cues from Apple? :eek: :p

PS Where's the OP? I think we're getting a little far from the topic. :p
Ahh... But it's so much fun. :p