New server array, need help with RAID card
I'm new to RAID arrays and basically just know the differences between the different types of arrays and have chosen RAID 5 for my server build. This server will be basically a home file server/exchange server so I want a lot of fast storage. I was originally planning on just using the onboard RAID controller on the motherboard but instead got a few drives for dirt cheap so I have some money to spend on a hardware RAID controller. I am unaware of any sites that benchmark raid cards so I was wondering what are your suggestions. My budget is about $200-250.
The main thing is to make sure that the card you get doesn't do software RAID. It must have the XOR engine built into the card. AFAIK all motherboard RAID 5 is software... The Perc 5/i card looks pricey - I suggest have a look at Adaptec.
Me , being me , I would question why you are going to that expense and trouble? Why not just go for RAID1? I struggle to see how a home server would benefit from RAID 5, I consider that you are adding additional cost for little benefit. IMHO!!! I'd run the drives in RAID 1 using the motherboard.
Biggest reason I could see not to run raid 1 is the fact he would need 4 HDs for raid 1 to to equal the same storage amount as 3 HDs in a Raid 5. I would go with 4 drives myself. 1.5 TBs storage and as you add more drives to a Raid 5 it gets faster IIRC.
Dave is right about the card though. You want a raid card that can handle all the RAID stuff on the card, not a software card. Adaptec makes some nice stuff in the 200-300 range that should suit you well.
The nicest thing about using a card is the fact you can move the array from PC to PC without a bunch of drama. You cant do that when you use the onboard mobo raid.
Kaldor said:Biggest reason I could see not to run raid 1 is the fact he would need 4 HDs for raid 1 to to equal the same storage amount as 3 HDs in a Raid 5. I would go with 4 drives myself. 1.5 TBs storage and as you add more drives to a Raid 5 it gets faster IIRC.
At the risk of too much of a debate . You are 100% correct on the space. I argue that the money the Dan will spend on a RAID card, $699 on Dell's website ( http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=341-3742 ), could buy a couple of extra disks. I would also suggest that it's a lot easier to move a disk & data out of a RAID1 array than a RAID5 array.
I'm going to ask you to reconsider your choice - that card appears to have limited motherboard support, you will need to find cables and additional disks are going to be pricey. SAS drives are MUCH more expensive than SATA drives. Finally, why do you need so much throughput on a home server? If you are able to get the maximum bandwidth out of the card you will not be able to send it across your network - at maximum the card will be pumping out at least four times more data than a 10base-t network can handle.
Some info on motherboard support:- http://forums.2cpu.com/showthread.php?s=9dfb1558104277934f1a7914980be035&t=84882&page=2Anonymous said:I'll be using 3x WD 500GB SATA drives.
The Perc 5/i card has a SAS interface not SATA so those drives won't work on it.
My 5c & GL with what ever route you decide to follow!
btw the card is a full hardware XOR.
Ahh, I didnt see the $699 price tag on that Perc card. Way overpriced for and unneeded on a home server.
I elected to go with a cheaper Promise RAID card with 4 internal SATA ports for like $60, 4 500gb Seagate HDs, and a gigabit NIC into my server, and thus far its working very well. Granted its not a hardware RAID setup, but for what I use this for its good enough. I needed alot of dependable storage for pics, movies, CD/DVD images. Serves me well enough for a total cost of less than $400.
UncleDave said:The Perc 5/i card has a SAS interface not SATA so those drives won't work on it.
I believe the PERC 5/i can use SAS or SATA drives.
However, having said that, there are other Enterprise-level RAID cards that are designed for SATA-only that are less expensive.
3Ware 9650SE-4LP, $329
Adaptec 2251800-R, $324
And, like UncleDave said, for a home server, you may not need this much throughput. If you're only going to be accessing the server over the network, most Windows-to-Windows file transfers cannot exceed about 40 MB/sec due to the Windows SMB code. Thus, disk performance kind of goes to waste for single computer accesses. However, there are other advantages:
Enterprise RAID cards work. They correctly handle a failed drive, they have robust drivers, they have nice features like RAID level migration and Online Capacity Expansion. Cheapies don't have these features. Cheap motherboard RAID controllers also have a tendency to fail without warning leaving you with a broken array, and frequently have problems doing rebuilds. To me, that's almost worse than a single drive.
If you're using this for a home server, where you're going to have so much data that it's not possible to back it up, then I would do nothing less than use an Enterprise RAID card simply because of the reliability. If there's no backup, you can't afford to have the RAID card screw you.
Of course, there is something about wicked transfer rates that makes you walk around with a perpetual smile on your face:
8x Seagate ST31000340NS, RAID 5, 3Ware 9650SE-16ML, 1MB block size transfers.
ASUS P5M2 mainboard, Core2 Duo E4500, 2.2GHz, 4GB RAM, Windows Server 2003
cjl said:OK, that is just obscene
Nice access times too - that is really quite impressive.
The access times are primarily due to the on-board cache on the 3Ware card (256MB). True random access time to the array for non-cached data is more like a single drive (12.7 msec) or somewhat higher.
That's actually another advantage that enterprise RAID cards generally have over the cheap ones. Most motherboard and software-based RAID have no cache, which can impact access times, read performance, and especially RAID 5 write performance.
A few things to think about.
I know you wrote you have the drives, but if you're going Western Digital, take a look at their RE2 or new RE3 enterprise drives. They are made for RAID. The other consumer-level models may not work. I know this because at work we made the mistake of using their pre-RE series drives (before the RE's were released) and our RAID failed miserably. Check the series before you build.
We have the same card at work as SomeJoe7777 but linked to ten 150GB Raptors and it positively screams. But, it's also a money sink. Turn on all the wiz-bang speed features and you NEED 3-Ware's $90 battery backup add-on card and a UPS for the server itself. You don't want to lose power when this thing is write caching.
Oh yeah, be careful with 3-Ware's BIOS. We had two successive RAID arrays die because of a defective BIOS that caused--get this--catastrophic data corruption when rebuilding a degraded RAID-6 array. Big headache. Lots of $$$ lost. Also, some of the enterprise cards are very, very finicky about what mobo they are compatible with so you have to watch that too.
So, the moral of the story is, enterprise RAIDs are badass, but they can be tricky. Do your research and/or have deep pockets.
Save up a few more dollars (~$300 seems to be golden figure) and go with some cheap WD RE2's in RAID5 using:
$310 3ware 9500S-4LP 64-bit/66MHz PCI2.2 SATA Raid Controller Card
$305 Adaptec 2251900-R 4-lane PCI-E SATA / SAS Adaptec RAID 3405 SGL/128
$330 3ware 9650SE-4LPML PCI Express Lanes: 4 SATA II Controller Card
$290 areca ARC-1210 PCI-Express x8 SATA II Controller Card RAID 0/1/1E/3/5 JBOD - Retail