Rocketraid series For External Drives

[slughead]

I did a computing job after being retired for many months, and I got paid in hard drives.

I am thinking of buying a rocketraid 2314 and making a RAID-5
http://www.newegg.com/Product/Product.aspx?Item=N82E16816115036

However, I also want to plug in my SATA DVD burner to the card at the same time. is that possible? A RAID set and a DVD burner on the same controller?

I've never done anything above a RAID-0 before so ANY info would be appreciated, especially having to do with this particular model (others are out of my price range!

 

[bigbossbmb]

why would you put the DVD burner on the RAID controller?

connect it to the ODD SATA port on the motherboard.

 

[slughead]

well presumably, if I can do that with a DVD drive, I could take the occasional hard drive and plug it in there too--Sort of like a portable hard drive bay.

Also, all my drive bays in my Mac Pro are full.

 

[slughead]

any info at all on highpoint would be great, guys

 

[nanofrog]

It's just a 4 port eSATA controller with software RAID from what I can tell.

Take a look at newegg's customer reviews. (Didn't look too wonderful).

If you want to go this route, you might want to look at either Sonnet or Nitro AV's offerings.

 

[slughead]

It's just a 4 port eSATA controller with software RAID from what I can tell.

Take a look at newegg's customer reviews. (Didn't look too wonderful).

If you want to go this route, you might want to look at either Sonnet or Nitro AV's offerings.

I thought software RAID used the computer's CPU. Are you saying this doesn't provide its own processing? I've never heard of a software RAID 5

 

[slughead]

Take a look at newegg's customer reviews. (Didn't look too wonderful).

A lot of the mac reviews were by people who didn't know what they were doing, or were using way different/old hardware like PPC. (the PPC driver sucks, apparently).

XLR8yourmac had a lot of positive reviews from 2006/7 Mac pro owners, but for some reason I can't get anything solid.

I'm so pissed, why is it so hard to get a good SATA controller for mac??!

 

[slughead]

I read the XLR8YOURMAC reviews and decided to go for it. The old software problems were mainly a problem solved in 2007. AMUG loved it, so did a lot of users.

There have been some Mac Pro 2008 owners, one of them had problems and thought it was a defective card. Another one was running two RAID 5's with like 4 drives each and doing great--very complex system yet still working? Probably okay.

Right now I'm working with a NORCO 4629 which is absolutely worthless on leopard. It kernel panics and wont even do a drive check anymore.

 

[nanofrog]

I thought software RAID used the computer's CPU. Are you saying this doesn't provide its own processing? I've never heard of a software RAID 5

It does exist. Some mother boards have software RAID 5 support. Some Asus boards IIRC, and a few others. (Tends to be towards the higher end models).

In this case, it didn't list an IOP, and the inclusion of the PM enclosure (port multiplier) compatibility, seems to be a major hint. Only the inclusion of cache sort of throws it a little.

Other than that, I was thinking more along the lines of reliability (DOA factor, not users misunderstanding it's actual functionality). If you know what you're doing, and understand the risks involved, you should be OK. The rest of it, drivers and firmware, are always a crap shoot. Sometimes it's well developed, other times it isn't. This is where vendor reputation helps, but is still not absolute.

HighPoint offers a range of cards, and some work well, other have a not so wonderful reputation. The 4300 and 3500 series are designed by Areca. They tend to review well, and would likely work as advertised. Not sure about the aggravation factor though. I'm not sure on who makes the rest of their line.

I just went back, and took a look at a photo of the card. No IOP. It's "heart" is just a Marvell controller chip, so processing will be offloaded to the system CPU.

 

[slughead]

Did not know that. Crazy stuff.

Is there a lot of risk of problems running a RAID 5 in "software" mode with no batteries or anything?

What kind of risks are we talking about?

Keep in mind the choices here are using time machine to selectively back up onto one of the drives and a 'software' RAID 5

 

[nanofrog]

Did not know that. Crazy stuff.

Is there a lot of risk of problems running a RAID 5 in "software" mode with no batteries or anything?

What kind of risks are we talking about?

Keep in mind the choices here are using time machine to selectively back up onto one of the drives and a 'software' RAID 5

I'm not a big fan of software RAID.

But whether hardware or software based, there's definitely additional risks involved without taking power outages into consideration. You need a UPS. If you run without it, you're begging for trouble. Though some are of the absolute impression that the card batteries (BBU) are required, they typically are not. Atto doesn't actually offer them, and Areca is actually recommending not to even bother. Nor do they offer the same level of protection a UPS can.

Ideally, it's not a bad idea to run both, but a UPS isn't really an option. Obviously no BBU in software RAID though, and makes the UPS the only line of defense.

The reasoning is simple. If you're in the middle of a write, and the power suddenly goes out, the data is lost in that write. You end up with corrupted files at a minimum. Perhaps even a trashed array, depending on the specific files. OS files for example, provided the OS is actually on the array. Granted, a BBU is designed to retain the cache data that hadn't yet been written, it doesn't help if the file data is larger than the cache. Particularly if the write was of multiple files, as the probability of them not all being stored in the cache is higher.

The UPS would provide a limited amount of power. It should be rated high enough for the system that you have adequate time to complete the write, and shut the system down.

 

[slughead]

I have a UPS already.

I guess the upshot is, I can toss a DVD burner on the card with an array and it'll work fine. Thanks for the help, frog.

 

[nanofrog]

I have a UPS already.

I guess the upshot is, I can toss a DVD burner on the card with an array and it'll work fine. Thanks for the help, frog.

UPS's are really good to have, even without RAID.

No problem. Hope it helped.

 

[slughead]

I installed the card today.

I was going to use it to try and salvage a software RAID-0 but apparently it's really fried. I'm currently testing the drives and am getting ready to make a RAID 5 from four 500gig drives (1.5TB total).

By the way, my DVD burner doesn't work with this card, I'm not sure why, I'm guessing this thing is only for hard drives. Really annoying.

The software looks pretty good, and I get an email notification if my drives start to turn to crap. The controller has full SMART capabilities and an emailer built in. I like it--lots of features.

Haven't really put it to the test yet, but everything spun up and was recognized just dandy on the first try.

OS X also doesn't see them as SCSI drives, which is interesting considering the Norco did. Gah, Norco.

Verdict: so far, so good.

 

[slughead]

Oh, how do you like this drive listing?

I'm also fixing another mac pro in the room which is running in target disk mode

 

[rylin]

I was going to use it to try and salvage a software RAID-0 but apparently it's really fried. I'm currently testing the drives and am getting ready to make a RAID 5 from four 500gig drives (1.5TB total).

Despite what one may think, all RAIDs (be they 0, 1, 10, 5, 6 etc) are not created equal.
Stripe size comes to mind as one of those things that would make one adapter work fine with an existing RAID, whereas the next adapter might not.

As for RAID-5, just don't.
It's an accident waiting to happen.

 

[nanofrog]

Despite what one may think, all RAIDs (be they 0, 1, 10, 5, 6 etc) are not created equal.

No, they aren't. The differences allow for redundancy.

Stripe size comes to mind as one of those things that would make one adapter work fine with an existing RAID, whereas the next adapter might not.

You don't want to mismatch a previous array built with x stripe size to adapter settings using y size and not expect to have problems.

As for RAID-5, just don't.
It's an accident waiting to happen.

What?

It uses parity, and can continue to operate (and be rebuilt) with one dead drive.

 

[sidewinder]

nanofrog,

I am assuming that rylin does not like the RAID 5 "write hole" problem.

RAID Z does not have this problem and is superior. That's why I would really like to see ZFS in the workstation release of Snow Leopard.

S-

 

[slughead]

Okay, well these are my choices: 0, 1, 5, 10, JBOD

I'd really like something like RAID 5.. what's the likelyhood of something bad happening... I mean, really.

 

[nanofrog]

nanofrog,

I am assuming that rylin does not like the RAID 5 "write hole" problem.

Ah... I ignored it, as I was thinking in terms of small arrays (on the order of 4 drives or so), and a UPS+BBU (hopefully, as the OP didn't yet have a RAID HBA).

For larger arrays, I agree, it's a problem that must be addressed. Skipping RAID 5 is the simplest.

RAID Z does not have this problem and is superior. That's why I would really like to see ZFS in the workstation release of Snow Leopard.

S-

As would I, but I still haven't seen anything indicating Apple will incorporate it into the client edition yet. So I'm figuring 10.7 ATM.

 

[slughead]

so... raid 5 ftw? ftl?

 

[nanofrog]

so... raid 5 ftw? ftl?

Ultimately, it depends.

• Number of drives & capacity of the drive used (storage density of the platter)

• Method of RAID (hardware vs. software/fake RAID)

• Power backup scheme (UPS, and BBU if available for the card)

The write hole is real, and is a serious problem as arrays (and drive capacities) grow. The risk for smaller arrays, say 4 drives (at ~4TB unformatted), using a UPS + BBU, is less than a much larger array (anywhere from ~10TB+). The difference of a single order of magnitude can kill your data. (Also why enterprise drives (1E15)are needed for RAID rather than consumer units (1E14), as the unrecoverable bit error (UBE) is 1E10 greater).

RAID still has risks, no matter the type used. So proper backups are needed. Spares as well. If you get lulled into a false sense of security, you will get bitten at some point in time. It's a question of when, not if. But if done correctly, the system is changed/upgraded before such a catastrophe happens.