I'm building a new machine and I ordered two, 1tb drives.
What would be the best way to set these up, right now I'm thinking RAID 1.
Reason being for its very low "failure rate" and its read speed increase.

I would do raid 0, but the fact that according to Wikipedia a failure rate of ~%10 throws me off.

Along with the internal hard drives I ordered (the two 1tb ones) I also currently have an external 500gb and 200gb.

What would YOU do?

RAID 0 is not really an option as if either drive fails, you lost all data. It's simply not meant for anything other than speed.

RAID 1 is fine but it can only save you from a drive failure. Since anything you do to one drive is copied at the same time to the other, any human errors (file deletion, windows corruption, etc) will be carried across both drives. However, it's better than nothing.

RAID 5 or 6 would be preferable if you had $$ for another drive, and if your controller supports it. If not, a good controller will set you back $300-500.

I should mention this will be a software raid.

www.drobo.com

martines34 that was irrelevant to my question
this is an internal setup, and the speeds with firewire/usb 2.0 are not what I want.

so what is your purpose in building the raid setup?

the Drobo is fully capable of streaming video and working images at the same time. as a redundant system it is an easy and very caspable turnkey system. i currently have 370GB of images in there out of currently 1.3TB of usable space. this is the first time i have felt more at ease with the assets i have in the little black box.

What is the noise like on the drobo... i know my western digital external is quite noisy.

i have 3 seagate ES2 500GB drives installed along with 1 400GB ES drive. FW800 thru a Belkin FW800 PCIe card. it real quiet. the only real sound is the cooling fan at various levels but only just. my video card makes all the noise on my system.

Adam Svoboda wrote:
I should mention this will be a software raid.

Stick with hardware RAID. If your OS gets corrupted say goodbye to your data. With hardware RAID you will still be able to get that data off the drive even if the OS does not boot up.

Also software RAID has a lot of processing overhead and will slow down the system. I would rather have a RAID card doing the work.

Adam Svoboda wrote:
martines34 that was irrelevant to my question
this is an internal setup, and the speeds with firewire/usb 2.0 are not what I want.

If you don't have room in your case you should consider an E-Sata Raid box.


Rosewill 2 bay Raid box $99

E-sata will provide you with the same speed as an internal drive. Thats up to 3gbit/sec if your using SATA-II drives.

I would go for RAID5 with a dedicated raid card (adaptec esata with hot plug), and even better, on a dedicated server which do only this. Put 5drives, one as spare in case one fail so it will automatically reconstruct itself and you can just swap the failed one in hotplug without rebooting anything. Put the server on a gigabyte network (rj=45 cat6) and just share the units on the network. I've set this on our 10 co workers network, run like a dream. We had raid 1 mirroring before but cost more when you need more space (2n for raid1, n-1 for raid5). Avoid raid0, it is for speed only and is le less secured one.

Nic

dan727 wrote:
Adam Svoboda wrote:
I should mention this will be a software raid.

Stick with hardware RAID. If your OS gets corrupted say goodbye to your data. With hardware RAID you will still be able to get that data off the drive even if the OS does not boot up.

Also software RAID has a lot of processing overhead and will slow down the system. I would rather have a RAID card doing the work.

Adam Svoboda wrote:
martines34 that was irrelevant to my question
this is an internal setup, and the speeds with firewire/usb 2.0 are not what I want.

If you don't have room in your case you should consider an E-Sata Raid box.


Rosewill 2 bay Raid box $99

E-sata will provide you with the same speed as an internal drive. Thats up to 3gbit/sec if your using SATA-II drives.

Thats a lot like what I have:
http://www.newegg.com/Product/Product.aspx?Item=N82E16822155003&Tpk=dns323

I have run raid off those crappy mobo chip sets and both pooped the bed and I ended up restoring. I dont find that they are reliable. Its worth googling to see how folks liked the RAID chipset on your motherboard before going that route.

I use the device above on my network with 2 500s in raid 1. My machine used to be a Raptor boot drive and everything else on 2 250s in RAID 0. Now after my last drive failure I just went to one 500 and I still boot off the Raptor.
I havent had any problems with my DNS323. I think it runs Linux

Keep us posted on what you end up with and good luck

sticking to shat you asked - if it's going to be a software RAID then RAID 1 is the only one worth bothering with. However, I would highly recommend buying at least an inexpensive hardware RAID controller.

I ran 2 x 320GB drives in a RAID 1 for photographs stored on my previous AMD A64 X2 system for internal drive mirroring - it performed well even though it was a SW RAID and gave me the confidence that if one drive failed, I'd still have the other alive.

I upgraded my system earlier this year to a quad-core Intel CPU with P35 chipset and added a third 320GB drive to run the three drives as a larger 640GB RAID 5 configuration. However after seeing how poor the write performance was of these drives (about 1/4 the write throughput of my previous RAID 1) I gave up on RAID 5 and added a fourth 320GB drive to create a RAID 10 configuration (mirrored stripes).

RAID 10 doesn't use disk capacity as efficiently as RAID 5 as RAID 10's full mirroring needs twice the installed drive capacity of your desired storage capacity with 4 320GB drives to provide 640 GB of storage capacity. Once the additional workload of writing the RAID 5 parity data is factored in, RAID 10 provides much higher write data transfer rates than RAID 5 via SW.

the drobo has some distinct advantages over all these. though slower in nature in shear thruput (that is i/o and system dependent) it is a simple non intensive self setup that is up and running in about 10 minutes including removing from its box and reading the instructions it is also on the fly expandible. in addition it is PORTABLE. you can if needed/wanted move everything to another system PnP. you can't do this with the others w/o way too much work.

in my current config i have 1.26TB of redundant space. that is the ability to protect 1.26TB of images that are redundantly spread over 4 drives and not even exactly the same sizes too. that are hot swapable and self healing. best thing about it is i don't need to even think about them.

I have 2 1Tb drives in my Mac Pro configured as software RAID 1. That way I am protected if 1 spindle fails and I have a 1Tb FW800 drive for Time Machine backups, plus another 1Tb located somewhere safe which contains a bootable system backup plus a full backup of my data drive.

Adam Svoboda,

Consider very carefully what you do. RAID provides only very limited protection against lost or corrupted files. Experience with software RAID is not assuring, it's a low cost solution and has failure modes that cannot be overcome-- low likelihood, but devastating when it happens. The same can be said about the hardware solutions. Many have proprietary controllers and data corruption may not be recoverable, except at very high cost. The bottom line is you can't trust any RAID for archival storage. You must have a backup strategy. AND you don't know if you have a real backup strategy until you try to do a restore. Caveat emptor.

oh so true

sjms: are you using the second generation Drobo or first? If you are using the second gen. what are your impressions? It is impossible to find reviews at this point and I would like to hear from someone who has one before I actually purchase one.

RAID is no backup... use it for initial safety but do real backups regularly onto external drives.

simon_k wrote:
RAID is no backup... use it for initial safety but do real backups regularly onto external drives.

Echo that!! The primary purpose of RAID is to provide high availability of data and NOT backup. Backup is backup. An effective solution will combine the high availability of RAID with the redundancy of a backup solution.

+1

RAID protects you from catastrophic data loss due to drive failure.

Of course, you need to actually back it all up to yet something else.

I have a 4 disk enclosure (qnap 409) w 3 drives: 2 of them for a RAID 1 and the other as independent backup of the RAID 1. That puts my data on 3 separate drives. Purists will say the backup should be external etc etc and I agree but that's my current system that I'm reasonably happy with.

umeboshi wrote:
sjms: are you using the second generation Drobo or first? If you are using the second gen. what are your impressions? It is impossible to find reviews at this point and I would like to hear from someone who has one before I actually purchase one.

brand new out of the box gen 2. it is not the speediest thing on the planet but its doing a whole bunch of management things inside while it sits there humming. i work on batch items rarely and individual images all the time so management is easy and its fast enough for my use. currently now have 400GB of images on it

Drive security, like any security, is all about layers of protection and how many layers is right for any given person is an individual choice. 2 drives in RAID 1 in a machine is fine, even if it is software based. Having nearline storage and offline storage, the latter in particular, is critical.

A couple of years ago a bolt of lightning hit a tree a hundred metres from my house. My house alarm, tv, cable, quite a bit of stuff, got fried. Luckily, this happened while I was asleep but I woke up very quickly when the house alarm went off. Again, luckily, my workstation and nearline drive were all unplugged from the mains at the time. My neighbour was not so lucky, his PC was still powered up but in sleep mode and he lost nearly all his data apart from a few old DVD backups. Yes, his PC was protected by a very good surge protector as well, not that it made much difference.

nma wrote:

Adam Svoboda,

Consider very carefully what you do. RAID provides only very limited protection against lost or corrupted files. Experience with software RAID is not assuring, it's a low cost solution and has failure modes that cannot be overcome-- low likelihood, but devastating when it happens. The same can be said about the hardware solutions. Many have proprietary controllers and data corruption may not be recoverable, except at very high cost. The bottom line is you can't trust any RAID for archival storage. You must have a backup strategy. AND you don't know if you have a real backup strategy until you try to do a restore. Caveat emptor.



I would very seriously listen to this advice if I were you.

I had raid 1 and Dell talked me out of using it. As is mentioned above, there are a number of failure types that cannot be recovered with raid 1.

I split the drives (2 x 500 GB). One is on-line for active backup. The second is off-line in a fireproof safe. About once a month I swap the two drives. Since I have two copies of everything and a a third copy that is at most a month out of date, I feel relatively safe.

Having said that, I am now trying an experiment, backing up on-line to Mozy. For home use it is $5/month with no quota. However it will take 3-4 weeks to copy my 320GB of data using a "high speed" cable connection. Once the initial backup is done, keeping it current should not be a problem.