*Hardware* raid question

[Rapamatic]

I am going to be building a new system and want to put a high quality IDE RAID setup in it, with the primary goal being data protection, not speed gains. I have done some reading and decided I do not want a software RAID setup. If I were to get a "traditional" hardware card I would be thinking something along the lines of a 3ware card. However, in a recent slashdot post I found a couple interesting alternative hardware solutions.

Arco makes several hardware RAID 1 devices that are totally transparent to the OS (i.e. you plug your IDE cable from mobo into the device, plug in two HDD, and everything is mirrored without any drivers, software, bios, etc. etc.)

Accusys also makes similar devices, including one device that takes up 2 5.25" bays and gives you a 3 HD RAID 5 array. Their products are also totally transparent to the OS.

Does anyone have any experiences with either of these devices? I know 3ware has an excellent reputation for supporting their products, and Arco seems to be similar - I sent a lengthy email with many questions that was quickly answered. The products also all havew a 5 year warranty (comparable to 3ware) and a 30 day satisfaction guarantee. However, I could not find much about either on any common hardware websites or google searches.

As I see it, the Arco and Accusys have the benefits of not using any system resources, not using a PCI card (and thus perhaps being limited in bandwidth), not being dependant on any driver, and the ability to unplug a HD from the array and use it any other PC like a regular drive (assuming a5 RAID 1, not RAID 5 array, of course).

Benefts to the 3ware solution and a decent HD cage would be flexibilty (can start with two HD in RAID1, go to 3 HD in RAID 5), and perhaps higher performance (especially if using RAID 5, and also in RAID 1 -- I think the 3ware card essentially stripes reads in RAID 1 whereas with the Arco you select one drive for all reads to be performed from), and the ability to upgrade individual components of my RAID system.

Any thoughts?

 

[Rapamatic]

anyone?

 

[StraightPipe]

^bump^ I've never used either card, I've got software RAID0 on and Adaptec 1200a. card was $60

I ran Winbench tests, and it showed my RAID setup using 25% CPU and my regular IDE is a 4.46%

but that's RAID 0

 

[AgaBoogaBoo]

No need for a very high end card if all you want to do is Raid 1. There is hardly any processing to be done for Raid 1 as it doesn't require as much processing as Raid 0 for striping. Raid 1 just basically writes the same thing to both hard drives.

 

[mikecel79]

I'm unsure what you mean by no drivers need to be loaded. Unless there is some kind of driver the OS (Windows, *NIX, OS/2, etc) won't know how to use the hardware. There has to be some kind of driver loaded. Even the expensive RAID controllers that come with our Compaq servers need drivers for them to run. Perhaps what you saw on slashdot was that to Windows the RAID array looks like a normal hard drive and the controller does all the calculations?

If all you want is RAID 1 then just get a Promise or Highpoint controller and be done with it. Like the above poster said RAID 1 has little to no overhead.

 

[capricorn]

I'd like to add to not count out motherboards with onboard IDE RAID. I've got two using onboard RAID-1 for the same reason you mention. (Who has the time or devices to back up 60 GB of data, let alone 200 GB?) One of my my motherboards is a GigaBtye Athlon board and the other an ASUS Intel P4 board. The former has a Promise controller and the latter has a VIA controller. Both work well. The hassle of setting them up is just a few BIOS settings and having a copy of the RAID driver on diskette or CD-ROM to be inserted at the proper time during OS installation.

-cap

 

[Pariah]

If your real goal is data protection, RAID is not the answer. RAID does not prevent data corruption, it only protects against drive failures which are not very frequent. An external drive with Norton Ghost or equivalent used to regularly back up would be cheaper and much more effective in protecting your data.

 

[Rapamatic]

Mike: It in fact does not use any drivers. It connects directly to the IDE cable coming off the motherboard and BIOS or any OS only sees a single HDD (the controler emulates a HDD). Check out the website. It is impressive technology and the first time I have seen anything like it. According to Arco:

Second, and this is an Arco patented feature exclusive to the DupliDisk, we plug directly into the ATA bus of the host computer. Our competition is forced to send data through the PCI bus. This gives the DupliDisk a significant advantage in that our method requires <B>no drivers</B>, IRQ?s, or Tray Resources. This also makes us hardware and OS independent. As a result, the DupliDisk3 is completely transparent to the host system, making DupliDisk3 the most reliable, secure and stable solution available.

Pariah: I realize the issues of HDD failure protection vs. data protection, that is where the hotswap and rapid rebuild capability of the Arco and similar systems appeals to me. With two or three HDD in circulation through the RAID array it is easy to keep backups. I guess it becomes a question of the usefulness of a RAID array. One thing thats nice is that *if* a HDD failure occurs there is no need for any user intervention to keep the system running. Also, a RAID array will have the most current backup set when a HDD fails (imagine using nightly backups, working all day on a project, and then having the HDD fail before the nightly backup). Convenience is also an issue. At least from my experience with Norton Ghost and similar products, it is a hassle to backup a HDD, typically involving booting into a proprietary OS, as I do not trust the real-time products. Backing up selective data is also a half-solution, as failures always happen at the worst possible time, often when re-installing the OS and apps is not an option.

I have been soured to promise cards in my current desktop. I am using a FastTrak 66, and the company totally stopped supporting that product, and has not released drivers for XP. The 2000 drivers wort of work in XP, but some functionality is lost. Also, when I installed XP SP1 I removed one HDD from my RAID 1 array (in case all hell broke loose), but after SP1 successfully installed, the controller refused to rebuild the array, citing bad sectors or some such.

 

[Pariah]

Also, a RAID array will have the most current backup set when a HDD fails (imagine using nightly backups, working all day on a project, and then having the HDD fail before the nightly backup).

The odds of your data getting corrupted by something are far greater than a hard drive crashing. In this capacity, RAID will do nothing to preserve your data. If a virus, file system corruption or anything else ruins your data, it all gets copied in real time to the mirror drive making your "backup" as worthless as the data on your original drive. This is why an external drive that isn't premanently connected to the system which contains drive images that can be easily be restored are the cheapest and safest method.

 

[440BX]

I have never had a hardrive fail and dont expect to.Plus with DVD-r being so cheap that would be a great way to back up anything important...I would defintly get raid built into the mobo for a new system and think about serial ata drives as there cabling is much better with great upgrading posibilitys.

 

[eklass]

what is it, RAID5 that he's looking for

it does something to the effect of this (with 3 HDDs):

sector sector check
sector check sector
check sector sector

for the price of 3 drives, you get a bit of combination between speed and redundency. if any 1 drive fails or gets corrupted for whatever reason, the controller can calculate what the data should have been based off the check that is written

 

[Sunner]

Still doesn't avoid the problems Pariah mentioned.
RAID is not a substitute for backups, RAID is for speed and availability, not backups.

 

[chocoruacal]

Originally posted by: Pariah

This is why an external drive that isn't premanently connected to the system which contains drive images that can be easily be restored are the cheapest and safest method.

Hard drives are the safest backup method?!?! I would disagree. DVDRs are cheap enough now, that if you have data that is truly important to you, at the minimum I would backup using that, since most of us can't afford $10K tape drives People are stupid....it takes a hard drive failure to get them even remotely interested in saving their data.

 

[0roo0roo]

Originally posted by: Pariah

Also, a RAID array will have the most current backup set when a HDD fails (imagine using nightly backups, working all day on a project, and then having the HDD fail before the nightly backup).

The odds of your data getting corrupted by something are far greater than a hard drive crashing. In this capacity, RAID will do nothing to preserve your data. If a virus, file system corruption or anything else ruins your data, it all gets copied in real time to the mirror drive making your "backup" as worthless as the data on your original drive. This is why an external drive that isn't premanently connected to the system which contains drive images that can be easily be restored are the cheapest and safest method.

i've had far more harddrives die on me then get wiped by viruses or whatever. sure backing up is good, but having a secondary level of protection from failure is nice. unless its mission critical, most people will not backup their stuff daily, its too mcuh trouble.

adaptec makes good stuff.

 

[Sunner]

Originally posted by: chocoruacal

Originally posted by: Pariah

This is why an external drive that isn't premanently connected to the system which contains drive images that can be easily be restored are the cheapest and safest method.

Hard drives are the safest backup method?!?! I would disagree. DVDRs are cheap enough now, that if you have data that is truly important to you, at the minimum I would backup using that, since most of us can't afford $10K tape drives People are stupid....it takes a hard drive failure to get them even remotely interested in saving their data.

So, how many DVD's to back up 150 GB of data?
30 or something?

 

[Pariah]

Originally posted by: chocoruacal

Originally posted by: Pariah

This is why an external drive that isn't premanently connected to the system which contains drive images that can be easily be restored are the cheapest and safest method.

Hard drives are the safest backup method?!?! I would disagree. DVDRs are cheap enough now, that if you have data that is truly important to you, at the minimum I would backup using that, since most of us can't afford $10K tape drives People are stupid....it takes a hard drive failure to get them even remotely interested in saving their data.

I don't know about you, but I'm not going to sit around for hours swapping 2 dozen disks to back up 100GB of data every day or even once a week. Ignoring the time is money saying, it's still not cheaper when you factor in the cost of the drive. If you use write once DVD-R's and back up frequently, it will be significantly more expensive very quickly.

unless its mission critical, most people will not backup their stuff daily, its too mcuh trouble.

I wouldn't waste my time backing up every day either, but Maxtor makes external drives that require you to push one button on the drive to make backups. If I had one, it certainly wouldn't be a huge effort on my part to push the button everyday before I went to sleep.