Seeking opinions on RAID 5 with XP Pro on Dell Server

[Yahdie]

I need to run a Line-of-Business application on an XP box (thats what the vendors support), but, I'd really like to avoid losing the app's database(SQL) in the middle of the day and then having to restore from the prev, nights backup.
So I'm thinking of buying a Dell Poweredge 840 with a hot-swap cage and doing RAID 5, runnig XP Pro or XP Pro x64. The system as configured includes a hardware controller.

Any opinions welcome, the system specs are below, a maximum of 5 concurrent users.

PowerEdge 840:
Dual Core Intel® Pentium®D 915, 2.8GHz, 2x2MB Cache, 800MHz FSB 84D28 [222-6543] 1


Memory:
1GB DDR2,533MHz,2x512MB Single Ranked DIMMs 1G2D5S [311-5209] 3


Operating System:
No Operating System NOOS [420-6320] 11


Network Adapter:
Onboard Single Gigabit Network Adapter, No TOE OBNIC [430-2017] 13


TCP/IP Offload Engine Enablement:
Broadcom® Dual Port TCP/IP Offload Engine Not Enabled NTOEKEY [430-1765] 6


Hard Drive Configuration:
Hot Plug Add-in PERC5i (SATA/SAS Contrl) supports 3-4 Hard Drives - RAID 5 HASR5 [341-3899] 27


Drive Cage Configuration:
Chassis with Hot Swap Drives for PE 840 CHHS [341-3900] 28


Primary Hard Drive Controller:
PERC 5i SAS internal Raid adapter, PCI -Express PERC5I [341-3902] 9


Primary Hard drive:
80GB, SATA, 3.5-inch, 7.2K RPM Hard Drive 80S2 [341-4203] 8


2nd Hard Drive:
80GB, SATA, 3.5-inch, 7.2K RPM Hot Plug Hard Drive 80S2HP [341-3905] 23


3rd Hard Drive:
80GB, SATA, 3.5-inch, 7.2K RPM Hot Plug Hard Drive 80S2HP [341-3905] 54


4th Hard Drive:
80GB, SATA, 3.5-inch, 7.2K RPM Hot Plug Hard Drive 80S2HP [341-3905] 51

 

[sandmanwn]

more memory. at least 2GB. SQL loves memory.

Other than that I would suggest dropping XP for 2003.

 

[Yahdie]

your right - I'll change that

 

[Madwand]

RAID 5 is sometimes a poor choice for a database server. It could be OK with a good controller, but RAID 10 would generally be easier to get right. RAID 5 can have problems with write performance, esp. small writes.

Dell seems to charge a lot for their drives. Sourcing these elsewhere could get you a better price and/or greater capacity. But you'd have to have someone set them up. I guess the drives might be priced with a labor charge built-in. Starting with bigger drives would be more important for RAID 10, as it doesn't expand as easily as RAID 5.

Depending on the application / load (or power costs), you might get some benefit from going to a newer generation processor -- these will generally be much faster despite having lower clock speeds.

You should pick 667 MHz RAM as it doesn't cost materially more.

 

[Yahdie]

We have an account with Dell so it's easier to get a system through them, and I have some flexibility with my budget (as long as I whine enough) so I could increase HD size, the expected config. for this App is 1GB RAM & 80gb HD hence my choice.

BTW Thanks folks for the input, I really need for this to work out.

 

[gse1]

Hi,

I've also bought some Dell PowerEdge servers recently for running database applications on top of a RAID5 configuration so I feel I know what I'm talking about here.

I think for the price that the Dell website reports you've come up with a very good system. So if you are sure your specs are adequate then I think you've got it right.

I do have a few friendly comments I can make tho )

- As sandmanwn says I would consider going for extra memory unless you are dead certain than 1GB will be more than adequate. It depends how tight your budget is. Personally I would go for it but then the servers I buy for my company are more enterprise level (generally PowerEdge 2950s)

- Consider carefully what level of support your are going for. It's great getting RAID5 so you can lose a disk but you need to make sure you get a replacement in good time. From personal experience Dell's level of support is very good (at least for my company) so it might be worth paying for extra support. The other possibility is to order a spare drive or two with the machine.

- I don't think £40 for an 80gig drive is particularly expensive when you consider the hardware support you are getting so I don't think going elsewhere to save a few quid is worth it when you consider the extra support implications.

- Defininitely run 2003 server if you are running Windows.

- From personal experience RAID5 is perfectly adequate for a database server. It's easy to setup and "get right" too, especially with the PERC controllers. It's true write performance isn't amazing but it'll be more than enough for your needs with 5 concurrent users.

 

[Madwand]

From personal experience RAID5 is perfectly adequate for a database server. It's easy to setup and "get right" too, especially with the PERC controllers. It's true write performance isn't amazing but it'll be more than enough for your needs with 5 concurrent users.

RAID 5 performance is pretty much determined by write performance. Any monkey can implement good RAID 5 read performance. So by "get right", I pretty much meant "deliver good write performance". Even so, as a hardware controller, the PERC ought to have good write performance.

 

[Yahdie]

Defininitely run 2003 server if you are running Windows

The vendor is only going to support XP Pro, so I don't have flexibility with that, maybe I should go with x64?

Even so, as a hardware controller, the PERC ought to have good write performance

For max 5 conc users should be adequate?

 

[Madwand]

For max 5 conc users should be adequate?

Sorry, I just don't know how it performs. This is why I advised RAID 10 -- this is safer, even "a monkey" could make it perform well

The "ought" meant that a hardware RAID controller has the potential for good write performance, and might have good write performance -- if they didn't hire monkeys to do the coding, or at least the right monkeys...

The other poster might have more details on how certain implementations perform. Also, if you have mainly on-line reads and off-hour writes for example, then even a really poor write implementation could be OK.

 

[gse1]

Defininitely run 2003 server if you are running Windows

The vendor is only going to support XP Pro, so I don't have flexibility with that, maybe I should go with x64?

I'm confused. You said you were buying straight from Dell. If so their website lists that they'll ship 2003 with the machine so it must be supported. However, if I've missed something and you really don't have the choice of 2003 then you might as well stick with XP I suppose. Don't bother with the 64bit version of XP as there is no point on a machine of this scale. The main reason for using 64bit versions of an OS is to handle large amounts of memory, very large processes or very large calculations.

Also, in terms of Vendor support. If you are only buying hardware support from them it shouldn't matter was OS you are running, hardware support is hardware support. I've argued the toss with a Dell techie in the past as I was running Red Hat Linux before they "supported it" I successfully argued that as the support is for hardware and I knew for a fact there was a hardware related problem that they send out an engineer. I won.

I can understand, however, if you do not want to risk having arguments. But it might be worth confirming their approach before buying the machine, they may say they will support the hardware even if you decide to run 2003.

Even so, as a hardware controller, the PERC ought to have good write performance

For max 5 conc users should be adequate?

Unless your users are going to be thrashing the hell out of the system, and I'm talking generating seriously high loads, you'll have plenty of spare capacity. It would probably handle 5 times as many concurrent users under standard conditions.

 

[Yahdie]

I'm confused. You said you were buying straight from Dell. If so their website lists that they'll ship 2003 with the machine so it must be supported

Sorry, I wasn't clear - that application vendor wants XP Pro, so i was going to buy the machine no-OS.

5 users will be writng/reading the database continually ....

 

[holy_cow]

Dell PERC controllers are good (processor and memory on the controller at least on the SCSI ones) so you should not have problems, also its 5 users, we're not talking about a high performance clustered server for tons of users...

The 2Gigs ram will be a great addition...

 

[bliq]

For what you want to do, 5 conc users, and a strong desire not to have to restore from tape, RAID 1 on a pair or even 3 enterprise class SCSI U160 or U320 drives is what you want.

Of course the kinds of queries the users run will determine if you want to step up to RAID 0+1/10 but in most cases, unless we're talking about huge joins on huge tables, RAID 1 on fast drives will do you.

Also on the memory front, more is better, if you can fit it in your budget.

You could do fiber channel which also adds some redundancy, again, it it's in your budget.

Drive-wise, you can buy from Dell to keep support, but bad drives don't tend to mess up the rest of the system, hardware-wise.

I was an administrator for more than 2000 Dell systems at one time in my career and we replaced drives a lot so we'd buy them in bulk from CDW, not Dell. Same brand and model but we saved something like $150-200 a drive (mind you, they were about $1000 a drive at the time).

 

[darkangelism]

XP is not a supported OS on Dell Servers, it will probably work, but dont expect help from Dell to make it work...the better solution is to use server 2003 and install XP on a virtual machine.

 

[Yahdie]

I love this Forum - good stuff....
Your suggesting RAID 1 (Hot swappable), why not RAID 5?

 

[gse1]

XP is not a supported OS on Dell Servers, it will probably work, but dont expect help from Dell to make it work...the better solution is to use server 2003 and install XP on a virtual machine.

There is a problem here that needs to be resolved for sure but I would favour either installing XP or installing 2003 server rather than delving into virtual machines. Either get confirmation from Dell that they'll support the hardware even if it's running XP (don't see why they can't personally) or get confirmation from the application vendor that you'll be using 2003. Explain the situation to both of them, i.e. that Dell wants one thing and the app vendor wants the other.

If you can't get an agreement I'd just go for plain 2003 server without a virtual machine. 2003 and XP are highly similar anyway so its not very likely you'll run into problems.

We might be able to advise you better if we knew what the software was....

I think at this point, however, you can be sure the machine will handle the load. Sure RAID 1 is an alternative but in this situation it's a case of 6 on one and half a dozen on the other.

 

[sandmanwn]

This will suit your needs just fine for a Line of Business (LOB) with 5 users.

If this company is expecting to add more users in the future you might want to think about SAS drives. Your raid controller supports both SATA and SAS. SAS is much faster than SATA or SCSI.

Ask them how much through put they need. If its more than 100mb/s then you should stick with the Raid5.

 

[darkangelism]

Dell will support the hardware, but not the OS, so yeah if there is a hard drive failure it can be replaced, anything that is obviously hardware. but XP driver support on hardware is hard to find go to support.dell.com click drivers and downloads(under popular support tools) and select the system type and then on the next page choose the OS as server 2003 and look at the list of drivers, then go do the same for XP...the XP list is less then half as long including no raid driver for PERC5/i and the server installation CD does not support XP, so you will need a floppy drive to install the raid drivers anyway. Also Dell raid management utilities do not work in XP and wont install. But any error like random reboots or anything that is not clear cut hardware issue, you will probably be told to install a supported OS and see if the problem is fixed. The reason is that XP is a client OS not a server OS.