Scared to buy RAID enclosure because of HDD type

[jollywolf]

After tediously researching and learning RAID for the last week I was all set to pull the trigger on an enclosure -- until reading reviews about compatibility issues with specific HDD types.

I don't have and don't plan on buying expensive Enterprise HDDs for a 4 or 5-bay RAID1 set-up. I had chosen the Sans Digital TRM4+B as my favorite because its software RAID, allowing me to configure multiple arrays and would not hide drive space like the hardware RAID controllers. For more info on that, I was told by Sans Digital that when using different size HDDs, the controller would match the size of all HDDs to the smallest drive size. So, if there is two 3TB drives and two 2TB drives, all 4 of the drives would become 2TB drives.

Anyway, the reviews killed it for me. I'm reading several reports about arrays falling offline, and when Sans responds to the complaint they almost always point the finger at the drive type not being Enterprise. So, I need a different recommendation or some advice about what to do here. The most difficult part is the money. I pretty much parked myself at $175 for an enclosure. Maybe that's asking for trouble, but if that's how you feel please just let it lie... I wish I had more dough to spend, but have to buy the drives as well.

Hope someone has some thoughts.

 

[Hellhammer]

Is there a reason why you need RAID 1? Its use is fairly limited, especially for consumers. In most cases a backup is a better solution because RAID 1 does not protect you against data corruption and accidental deletes for example.

 

[jollywolf]

Hey, Hellhammer. Well, I kind of see your point. Like, if 1 drive starts corrupting then the data will be mirrored to the next drive right?

On the other hand, I can't think about a better solution for back-up when we're talking about 2-3tb of data per array that changes daily. That means I'd be doing day-long back-ups once a week, and this is why I'm looking for RAID as a solution to that now.

I would consider RAID5, even RAID10 maybe... but it's not about speed for me, only about redundancy... and I've read enough to about RAID5 that a single drive goes out, the whole array may never be repairable. I'm choosing RAID1 cause it seems to have the highest security for hard drive failure in full.

Thoughts?

 

[Hellhammer]

Remember that RAID 1 is NOT a backup. I see your point about RAID 1 but you must backup the RAID 1 array as well. RAID 1 only protects you against a drive failure, there are still lots of other things that can go wrong.

If all you need is 3TB or less, then I think getting a 2-bay enclosure would be sufficient. Put that in RAID 1 and you got protection against a drive failure. Then get a 3TB (or bigger) external and use it for backups of the important data (you said the data changes daily, so there may not be a need to back everything up).

 

[jollywolf]

Actually, my needs are bigger than the 3TB. I'm looking to start with two 2TB drives and two 3TB drives... in RAID 1 giving me 2 arrays for a total of 5TB.

I'm still left with this dilemma about choosing an enclosure since the consensus with these Sans Digital enclosures is not to use non-enterprise HDDs. I still appreciate your input.

 

[talion83]

The big difference you get with enterprise drives is QA - the drives are a higher quality providing a longer lifespan and meaning they might actually meet the specs they are intended to meet.

For RAID 1 it should be less of an issue also because you aren't doing striping - normally in those circumstances is when you want enterprise because you need the drives to match each other in all specs as closely as possible (and I don't just meet the quoted specs on the box - what the actual real world performance of them is. Again, QA of the drives).

As far as the RAID 1 vs Backup goes - I actually use my RAID 1 on my backup drives. The data is compressed by the backup agent so it is (hopefully) smaller than the RAW data anyways. This gives me redundancy on the backup so if I do have a failure on my 'live' side, I can restore from the backup. And if the backup has a failure - well it is in RAID 1, so I have a backup of my backup.

 

[jollywolf]

talion, thanks for your reply. That makes me feel more comfortable about proceeding with this.

Maybe you can help me by telling me which raid controller card would suffice for my needs. I need 2 arrays. I don't care if it's hardware or software. But, after talking with Sans Digital, it appears the hardware controllers only allow for 1 array.

Any thoughts?

 

[nk215]

The different between enterprise HD and consumer HD in a RAID is not about QA. It's about the "green" feature in some consumer HDs.

Basically, a raid controller has a set time to wait for the HD to response before tagging the drive as failing. Some consumer drives takes its time waking up which confuses the controller.

Further more, a consumer HD is rated for 8 hrs/day. Enterprise HD are rated for 24 hrs/ day.

Having said that, any none-green HD should be fine in a RAID setup. The Samsung F4 is very popular in RAID setup. I have a 5-2TB Raid 5 Array running none stop for years.

I personally think a $175/enclosure is asking for trouble in a long run. Those enclosure would be slow, unreliable, in-adequate cooling etc. With that budget, I would get a cheap hardware raid 5 ($100) and use the computer case. DAoptic will sell you an internal HW raid that acts like an external SATA (5 hd connect to the card, one SATA cable going from the card to your motherboard SATA port, no need for PCI bus)

 

[lopri]

RAID1 isn't a backup but as long as you're being careful it's better than nothing, IMO. Especially software-raid is in some ways safer than controller/drivers-based.

Have you thought about building a low-power system with spare parts or used parts that can be bought cheap? Yeah it takes up more space and could be ugly but it may be better than an enclosure long-term.

 

[jollywolf]

Having said that, any none-green HD should be fine in a RAID setup. The Samsung F4 is very popular in RAID setup. I have a 5-2TB Raid 5 Array running none stop for years.

I personally think a $175/enclosure is asking for trouble in a long run. Those enclosure would be slow, unreliable, in-adequate cooling etc. With that budget, I would get a cheap hardware raid 5 ($100) and use the computer case. DAoptic will sell you an internal HW raid that acts like an external SATA (5 hd connect to the card, one SATA cable going from the card to your motherboard SATA port, no need for PCI bus)

RAID1 isn't a backup but as long as you're being careful it's better than nothing, IMO. Especially software-raid is in some ways safer than controller/drivers-based.

Have you thought about building a low-power system with spare parts or used parts that can be bought cheap? Yeah it takes up more space and could be ugly but it may be better than an enclosure long-term.

Thanks for your replies, nk215 and lopri.

Can I ask what type of enclosure you're using?

Also, while your suggestion seems like a nice solution, it doesn't fit my needs exactly. I don't want to run RAID5. I simply want to run RAID1. I did read your reply entirely, I'm just pointing at that still leaves my dilemma unsolved -- mostly because I'm a total newbie to RAID. Note to nk: The reason I decided against hardware RAID was because Im concerned about losing drive space. At this point, there is different size drives going into the enclosure (two 2TBs, and two 3TBs)... I was told if I did this I wouldn't have a total of 10tb, I would lose 2tb because the hardware would match all the drives to the lowest space available drive, the 2TB.

I'm not sure I even care about eSATA at this point. Speed isn't my biggest concern, it's simply the ability to have a back-up drive getting data redundancy. I want 2 arrays, and 4 HDDs.

Tell me, do you think I can run a Windows software RAID set-up with this enclosure:

http://www.newegg.com/Product/Produc...82E16817576001

... and, not have to worry about any additional components? If I'm plugged in through USB2 (or USB3 if I upgrade), I can still configure the array through Windows Disk Manager -- is that correct?

 

[Red Squirrel]

I find software raid is always easier as you don't have to worry so much about using enterprise hard drives. Look into Linux MD raid. Just avoid green drives as suggested. They go to sleep and then get marked as a failed drive. I learned that the hard way... the work around is to have a cron job that runs every 5 minutes or so and does a bunch of I/O. It's dirty but if you are on a tight budget it works. Green drives are usually really cheap.

 

[jollywolf]

I find software raid is always easier as you don't have to worry so much about using enterprise hard drives. Look into Linux MD raid. Just avoid green drives as suggested. They go to sleep and then get marked as a failed drive. I learned that the hard way... the work around is to have a cron job that runs every 5 minutes or so and does a bunch of I/O. It's dirty but if you are on a tight budget it works. Green drives are usually really cheap.

Red Squirrel... No Linux, Win 7. Thanks for pounding the stay away from Green drives consensus. I will heed your words of wisdom.

 

[Zargon]

I used green drives with a sans digital array for over 2 years w no issues. Used the raid card they included. It held data so it could be written to tape so I used raid 5 to get storage space

Tapatalking on my pos thunderbolt. Sorry for teh typos!

 

[talion83]

talion, thanks for your reply. That makes me feel more comfortable about proceeding with this.

Maybe you can help me by telling me which raid controller card would suffice for my needs. I need 2 arrays. I don't care if it's hardware or software. But, after talking with Sans Digital, it appears the hardware controllers only allow for 1 array.

Any thoughts?

While I have always used consumer drives for my personal RAID setups - my 'home server' has actually been an older retired server using PCIX (not PCI express) RAID controllers.

As to the Green Drives - I've also used them without an issue, but again that may be also because I've been using an 'enterprise' RAID controller.

So I apologize but I don't have much experience/help when it comes to external enclosures or PCIE RAID controllers.

 

[_Rick_]

As far as I know Linux md RAID does not spin disks down, unless you specifically send that command via hdparm.
Anyway, none of the 12 disks in various RAIDs in my Linux server ever spin down. Should be 5 WD greens in there at least.
Of course, some distributions/configurations might favor more aggressive spin down time outs.