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What RAID 5 to buy? Need urgent recommendation

Last response: in Storage
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December 26, 2005 12:59:11 PM

Hi,

Thanks in advance for all possible replies.

This is the cross-road we're in:

We need very large storage and NAS are expensive. We do need data to be safe also. We will install 4x300GB drives. Need RAID 5

The two choices we have are:

1) Buy a PCI RAID card like INTEL SRCS14L (4 port SATA1 hardware RAID w/64MB cache). Or 3ware or any other reviewed card in THG last SATA RAID which are very powerful, have hardware XOR offload, auto-rebuild, battery backup, cache, etc.

This cards are quite expensive, and the computer that is serving data today is an Athlon XP 2000+ which is hot.

2) Get a D955X or similar, with ICH7R, and use the Software RAID, move to a P4 3GHz or so, 1GB RAM, and use the software RAID 5. Which might have the same final cost of a hardware RAID solution.

This "server" only does file-serving. Will use Windows and maybe SFU (Services for Unix) to give NFS support... This last choice will also add to that computer a GB Ethernet, x64 support, etc.

What I don't know, and there is not too much info on Intel site, (or is too hard to find) is how does it works with Auto-Rebuild, how much CPU will the XORs take, etc.

And mainly how safe will data be?

If I format the boot drive, will it recognize the array?

Any other info will be greatly appreciated.

Thanks again.

David.
a c 110 G Storage
December 26, 2005 2:33:50 PM

Here is a pge with info about RAID's

http://www.pcguide.com/ref/hdd/perf/raid/levels/singleL...

I personally would bite the bullit and get hardware RAID major advantage is no downtime when you lose a drive and less CPU intensive since hardware has its own controller like SCSI
December 26, 2005 2:55:59 PM

Quote:
Hi,
1) Buy a PCI RAID card like INTEL SRCS14L (4 port SATA1 hardware RAID w/64MB cache). Or 3ware or any other reviewed card in THG last SATA RAID which are very powerful, have hardware XOR offload, auto-rebuild, battery backup, cache, etc.


There are cheaper alternatives like HighPoint that offers raid5, like this rocket raid 1640, don't know how it compares to the intel job, but the saving is huge if you can maintain a raid5 with this much cheaper controller.

k
Related resources
December 26, 2005 3:25:03 PM

1) Guys, I saw the explanation about RAID 5 long ago at that page, still I knew about that long ago.

2) The RocketRAID 1640 does not support RAID 5.

The 1544 does, but they don't talk about auto-rebuild, nor SOFTWARE/HARDWARE RAID

(Have to investigate about this one, but many hardware pieces that are RAID cards, are software raid 5)
December 26, 2005 3:35:17 PM

Quote:

2) The RocketRAID 1640 does not support RAID 5.


On their homepage it says raid 0,1 and 10 8O

k
December 26, 2005 4:20:09 PM

Thanks,

Anyway I don't see them claiming hardware support for XORs
December 26, 2005 4:26:38 PM

Quote:
Thanks,
Anyway I don't see them claiming hardware support for XORs


I guess there is a reason they're priced lower than the intel card. All depends on whant you can afford/need. They don't have onboard cache either.

k
December 26, 2005 4:34:07 PM

Quote:
Thanks,
Anyway I don't see them claiming hardware support for XORs


I guess there is a reason they're priced lower than the intel card. All depends on whant you can afford/need. They don't have onboard cache either.

k

That's why it doesn't make any sense to have a RAID card, when you can buy a motherboard with RAID then.

Unless your motherboard is old enough and you don't want to change it. But will be moving to the 955X with 8 SATAs
December 26, 2005 6:08:45 PM

If RAID PCI card has no hardware acceleration or cache, then you are better off going with onboad solution, since performace is similar and cost is included with board.
But if you want the fastest most reliable RAID solution, then a hardware accellerated RAID card can not be beat! Just plan on spending over $200 for a good RAID card, but it is worth it if you need RAID.
December 26, 2005 6:12:23 PM

That's something I understand, and as you can see, that's the other hand of what we could use. The point is a good HW RAID is 600USD in USA, meaning here, about 1000 USD. And you have to import them.

Also, the problem is that the actual computer is a piece of... crap

And nobody did a recommendation on a 100% HW solution.
December 26, 2005 6:17:26 PM

Have you checked out NetCell Controllers

They got good reviews and are under $250 for their top model supporting 5 drives, SATA or IDE models.

Hardware XOR engine, 128megs cache and use windows drivers, so no boot disk is required installing windows.

SyncRAID
December 26, 2005 6:27:18 PM

Now, that sounds WAY good.

Still I don't understand since they claim it's driverless and they don't advertise you can use Linux...

Also, in many parts of their page, and others, parts mention RAID 0,1, JBOD, other parts of the text mention RAID 3, 5... etc.. but there is no serious SPEC..

I will still look around for that, and look who can get those in here.

THANKS!
December 26, 2005 7:23:30 PM

Purchase a Snap 4100 on ebay for $300. They are design for heavy use. Software is user friendly. If you are using 300gig drive you will need v4 OS and Hardare and bios version >2. They want be as fast as a pentium4 class computer. But you want be working on it all the time. It also want have to deal with MS bloaded OS. It runs on a unix platform.
December 26, 2005 8:14:45 PM

It supports a varient of RAID3 actually, and gets very high reads/writes and reliability, but not as high a number or i/o as RAID 5, making RAID 5 better for servers, and NetCell better for large file transfers.
Good system, very little negative reports, but do not know about linux support.
December 27, 2005 12:27:20 AM

Thanks for the Snap idea, sounds good but not doable down here.

About the Netcell, I've asked XFX and will ask PNY and Netcell about it.

Sounds like the best solution.

The Snap is a good idea, still will have to pay for the OS and Firmware upgrade.

I was looking at them before, but they are really expensive.

Will search eBay just for curiosity
December 28, 2005 10:03:28 AM

I think it's best to stick to either 100% hardware RAID or pure software RAID (under Linux) for example. The cheaper controllers on the market are worst than either pure hardware or pure software solutions. 100% hardware RAID can outperform software RAID but a pure software RAID can outperform the cheapter controllers on the market. Quite a number of SAN providers use embedded Linux (or FreeBSD) in their solutions, and I believe that this is also the case in the NAS market. Just my $0.02 worth.
December 28, 2005 10:10:31 AM

I like your observation. I just feel the same way.

I'm going to try the Netcell, and see what happens. I hope I can update in the future with good comments.
December 28, 2005 10:46:08 AM

Just a note. When you come to buy the hard disks, it's a good idea to:

1) Make sure that they are the same speed

2) To not buy them of the same type at the same time. If there's a defective batch and you buy the same type at the same time, then if one hard disk fails, it's likely that another will also fail. You might not even have time to replace the defective hard drive and then your RAID would be toasted.
December 28, 2005 11:02:56 AM

That's a good idea, but it is also a good idea to buy from the same brand/model/batch, so they all run alike.

Still I don't think that they'll all fail the same day if they belong to the same batch.

The problem is that I have to buy them at the same time.
December 28, 2005 11:37:16 AM

I think it's just important that they at the same RPM speed and have the same cache size so that they perform roughly the same. But as I mentioned, if one goes down, then it's a lot more likely that another might follow if they are all from the same batch and the batch was defective.

One final note about hardware raid that you should be aware of and this is the reason that if the load doesn't demand that extra performance that hardware raid will provide me I prefer software raid:

There's the issue of 'what if I need to move these disks to a different server'. One that doesn't have the same raid controller. Well, it wouldn't work. And if something happens to the hardware raid controller (it gets damaged or just stops working 3 years down the road), well, you can't get your data back unless you get the exact same hardware raid controller although I'll admit that some vendors, such as 3ware, will help you out. Just my $0.02 worth.
December 28, 2005 12:02:45 PM

Another great apreciation.
!