Need a good hardware (XOR) SATA-II RAID5 Controller

[Solema]

Hi Guys and Gals,
I am looking for a solid 4-port SATA-II RAID-5 controller with hardware XOR and battery backup for my neighbor's new server he ordered. He runs a tool shop and his building is subject to brownouts at times, so battery backup for the RAID cache is necessary. I'm really trying to find a card that performs well, with the BBU and XOR processor, for as close to $400 as possible.

I've looked at 3ware's 9650SE and Promise's SuperTrak EX4350, but both come in at over $500 with the BBU and my neighbor's budget is really tight. Anyone have any other ideas I can look at? This controller will be powering 4 320GB 7200.10's in a Dell SC1430 server.

Thanks!

 

[Rubycon]

Text

BBU is not a *requirement* UNLESS you have write back cache enabled. It's recommended, however.

If you have a good UPS (which is highly recommended) you can enable write back without the battery. Of course you would not be protected against something along the lines of a power cord getting yanked from the server but the chances of that are relatively slim. (I hope!)

 

[Solema]

How much of an improvement does enabling write-back cache provide?

 

[Rubycon]

Originally posted by: Solema
How much of an improvement does enabling write-back cache provide?

It depends on the role of the disks/logical disks attached to the controller. RAID5 benefits from it the most. RAID5 with write through will have write speeds about half the speed of a single disk in MOST cases. With write back cache the write speeds will jump until the data blocks regularly exceed the cache. For light office server use a controller configured in write through mode - even RAID5 - will do just fine.

 

[Solema]

Well, lemme give you the lowdown on what this server will be doing:

My neighbor runs a tool repair and sales shop with about 8 XP workstations connected to a Windows 2003 server. The server runs Exchange 2003, Active Directory, Antivirus, file and printer sharing, and its main critical application, PeachTree Quantum Server. The workstations run separate instances of Peachtree 2007 and connect to the server. The main issue is that PeachTree Quantum 2007 is a bloated and a resource hog, even with only 8 users accessing it. Also, since PeachTree holds all of their financial and transactional data, its database integrity is of absolute importance, but we also want the thing to run fast. Its current machine (dual-core AMD X2 box with 2GB of RAM and onboard RAID 1) is just choking on the software when every user is connected to it.

The new server we got is a dual-core Woodcrest Xeon server with 2GB of RAM and we have four 320GB SATA-II 16MB cache disks just waiting for a SATA-II RAID5 controller. I want this thing to go fast, and my question is, will enabling write-thru cache and getting the battery backup make a noticeable difference in speed? Enough to justify the extra $130 cost of the BBU?

 

[Solema]

Any more advice based on my usage scenario?

 

[RebateMonger]

You might want to enable some Windows Performance Counters and see exactly where the bottleneck is.

 

[Rubycon]

Originally posted by: RebateMonger
You might want to enable some Windows Performance Counters and see exactly where the bottleneck is.

Yeah that's not a very high workload. But yes RAID5 will benefit from a fast IOP and plenty of write through cache.

 

[Solema]

So it is worth it to get the battery backup module and enable the write-back cache?

 

[Rubycon]

Originally posted by: Solema
So it is worth it to get the battery backup module and enable the write-back cache?

Absolutely. Small file write performance will increase dramatically.

 

[Solema]

Thanks so much. That's the answer I needed. Looks like I will be recommending my neighbor get the BBU as well! Thanks so much

 

[bob4432]

it still seems like a ton of hardware for 8users....is wink2k3server that bad? win2k server was pretty low in the hardware dept and this hardware would have been more than adequate.

i would trobleshoot and see what is causing all of this usage - i have heard of bloatware, but this seems like a little excessive...

 

[Solema]

I really think that it has to do with the PeachTree software in conjunction with the onboard RAID1 setup. I can tell you that the PeachTree software sucks big-time in the resource department. He had to upgrade all of his workstations just to run the software decently.

 

[Rubycon]

Originally posted by: bob4432
it still seems like a ton of hardware for 8users....is wink2k3server that bad?

No it's not. But with an Exchange database, Anti Virus (which one?) and PT (is that using Btrieve?) all on the same box a bottleneck can quickly develop.

Even hardware that should be able to run this can get into trouble if not optimized. In the ideal world EACH database should have its own PHYSICAL disk (NOT partition) as should the paging file and OS. But that gets expensive especially when redundancy is required.

 

[Solema]

Yeah, I don't have the resources to set up separate redundant physical disks, which is why RAID 5 performance is so important to me. PT uses Pervasive SQL which is just as much a resource hog. Hell, the minimum spec recommendations for PeachTree 2007 Quantum are:

2.8GHz P4 or higher
1GB of RAM

That's just for the workstations!

I am also wondering. If I got that 3ware RAID controller without the BBU, could I set up the array and the server and see how it runs with write-thru instead of write-back cache, and then if we want to get the BBU later, can I switch it to write-back without recreating the array?

 

[bob4432]

Originally posted by: Solema
Yeah, I don't have the resources to set up separate redundant physical disks, which is why RAID 5 performance is so important to me. PT uses Pervasive SQL which is just as much a resource hog. Hell, the minimum spec recommendations for PeachTree 2007 Quantum are:

2.8GHz P4 or higher
1GB of RAM

That's just for the workstations!

I am also wondering. If I got that 3ware RAID controller without the BBU, could I set up the array and the server and see how it runs with write-thru instead of write-back cache, and then if we want to get the BBU later, can I switch it to write-back without recreating the array?

too bad he won't switch to a more efficient software package

 

[RebateMonger]

Originally posted by: Solema
I am also wondering. If I got that 3ware RAID controller without the BBU, could I set up the array and the server and see how it runs with write-thru instead of write-back cache, and then if we want to get the BBU later, can I switch it to write-back without recreating the array?

i just set up a 3Ware 9500 Series RAID array. It appeared you can turn the Caching on and off at will. There was no mention of having to do anything else with the array but turn the Caching on/off in the RAID BIOS. Similarly, as near as I could tell, you can add the BBU whenever you wish. Note, though, that I DON'T have a BBU for mine, so I can't test this.

 

[Rubycon]

Areca controllers WILL allow the use of write back cache without a battery installed. I'm told with a battery, the firmware will hold the cache contents longer (increase flush time period) to improve cache hit ratio. I don't know if this applies to the entry level ones, but it sounds like a way to ensure even better performance along with fault tolerance.

 

[Solema]

If I understand, though, enabling write-back cache without a BBU will lead to data loss if power is interrupted while a write is being performed but hasn't been committed to disk. Is that correct? My neighbor's entire business is dependent on PeachTree (the main reason it would be nigh impossible to switch software packages) so he cannot afford the database becoming corrupt due to a power outage.

 

[Rubycon]

The server should ALWAYS have a UPS. And it should be configured to shut the server down after say five minutes (only longer if it has ample run time) PROPERLY.

The BBU is in place to prevent interruptions such as a hardware power supply or motherboard failure which is not nearly as common as a power interruption due to lightning or a drunk man crashing into a utility pole.

That being said, the ~$100 or so for a BBU is a wise investment.

 

[Solema]

The server does have a UPS, and a good one at that, and the server will be shut down in the event of a power loss. But you hit the nail on the head, I am afraid of what would happen if the power supply died. My neighbor couldn't afford a server with redundant PSU's, so if am deathly afraid of what would happen if the PSU died.