Dependable SCSI RAID Controllers for Linux?

PalmKiller asks: "I have been using DPT (now Adaptec) SmartRaid controllers for years with great results in Linux, but with the advent of the Adaptec assimilation they became more unreliable in current kernels (in the 2.2 or 2.4 tree)...at least for the DPT SmartRaid V and Adaptec branded equivalents, ie: the kernel panics under stress...you know when you try to use it for anything but an idle uptime box. The crashes have something to do with 5 minute long command queues creating havoc in the kernel. I have a few SmartRaid IV controllers that plug away without issue, but they use a different driver. I suspect the programmers and people who knew how to program the Adaptec/DPT controllers got lost in the buyout, or perhaps driver quality control took a dive. I would greatly appreciate other Slashdot readers opinions on a good replacement that is available in the US."

"I have been considering ICP Vortex RZ and RS series and AMI Megaraid as possibles, along with the Mylex line of controllers. I would like some opinions, praises and even nightmare stories on any of these. I am not wanting to invest $350-$1500 per controller on another nightmare like Adaptec/DPT line. It should be obvious but cost is not primary, reliability and to a lesser degree performance are the key issues. In addition I run my controllers in RAID 5 with a hot spare, so suggestions should be for controllers that can do that RAID mode and ones that can be administered from a running Linux system so I can do hot swapping. I would also like controllers whose manufacturer keeps current patches available for the stock kernel tree or is in the kernel tree (for both 2.2 and 2.4, I use 2.2 mostly due to issues with 2.4) as I never use a canned kernel after the install is done. If you run Windows or some other truthfully Adaptec supported OS look for a few *good* DPT or Adaptec controllers on eBay when the swap-out is all over."

Comments

AMI sold the Megaraid divison to LSI

[Toraz Chryx]

an LSI Megaraid should work quite nicely in Linux, I have an older AMI Megaraid Enterprise 1200 (model 428) with a couple of small disks as my linux disks (and one of them is my windows swapfile :)

never had any problems with it whatsoever.

IBM ServeRaid

[Ringlord]

We have two IBM Netfinity servers that use IBM ServerRAID 3L. The cards are not that great as they only have 4 MB of cache, but they run reliably under 2.4.13.

The drivers are maintained in the kernel, so there is now patching or downloading of drivers.

I think IBM has other models that come with more cache, so you could try calling them.

Re:IBM ServeRaid

[velkro]

Disclaimer: I'm an ex-IBMer, who worked in the Linux services area.

I've used the 3[hl] and 4[hl] series of ServeRaids for over a year under Linux (both 2.2.x and 2.4.x kernels) with decent results. I currently have about 15 IBM x340's with ServeRaid 4l's running in production for nearly a year - no problems so far, however I did avoid early 2.4.x kernels (only upgraded after 2.4.7). I've suffered through failed drives and whatnot without datalos.

If you can find the ipsutils.rpm out there you can manage it from the commandline, otherwise the Java-based ServeRaid manager will let you do everything the Windows tools to under Linux.

Compaq

[JediTrainer]

Don't discount the Compaq line of SmartArray controllers. I've been using one for 2 years without a hitch. Supports everything you need them to do (I'm using the Smart/2P controller in my server). Never had a single problem with it. You can find these on eBay really cheap too.

Re:Compaq

[Chuck Milam]

I would agree. Compaq SmartArray driver support has come a long way in the past 18 months: I had a Compaq to put linux on, and 18 months ago, I couldn't get the SmartArray controller to work well as mouch more than just a straight SCSI controller. So, I switched to an ICP Vortex. 18 months later, while doing some hardware upgrades, I switched the SmartArray card back in, and went to Compaq's web site for flash updates and driver information. Amazing what a difference a year and a half makes--went from little to no information to "Oh my god! There are so many support options and Linux drivers I'm not sure where to start!"

The SmartArray works great. The little lights now light up on the drives (ya know, green, yellow and "uh-oh"). Heh.

Re:Mylex controllers are junk

[Quixote]

We've had issues with Mylex too. Here's our setup: a P-III 1GHz box with a Mylex eXtremeRAID 2000; an Adaptec 2940UW and a 2944UW. One of the Adaptecs is hooked to a Sun A1000 (which has a "Symbios" RAID controller built in, but we're using as a JBOD).

Anyways: when we hooked up the A1000 (our Sun server died), the system suddenly became flaky! We boot from a standalone SCSI disk, so booting wasn't a problem. But the Mylex would lose its settings; half the disks in one of the trays wouldn't show up, etc. We spent days trying to figure it out, but to no avail.After repeated messages to Mylex support, we get the solution: disable the BIOS on the Mylex. It turns out that the Symbios RAID controller in the A1000 was confusing the Mylex BIOS! Even though the A1000 was on a separate Adaptec controller. Go figure.

Compaq is worth a look

[un4given]

Compaq's SMART array controllers work well under Linux, and support RAID 0, 1, 5, and 0+1 with hot spares. I have been running RedHat 7.1 on one of these for months, in a production environment, with great success.

ICP Vortex

[IpSo_]

I work for a medium sized web hosting company which sells dedicated/managed servers to customers. We will only put ICP Vortex cards in them. These are the only cards we put in our own servers as well, I would say we have at least 40 of them in our datacenter and they work great. Not to mention if a drive fails you can easily hear them beeping from outside the datacenter, even with all the server/air conditioner noise.

Great cards, great speed, and a not so bad price. They work flawlessly in Linux and Windows.

Re:ICP Vortex

[Zurk]

yep. i'll second that. ICP vortex also has linux utilities to control the cards from within linux instead of booting to DOS. i've never had any problems with vortex controllers. just make sure you use a stick of good (crucial or somesuch) ECC SDRAM for the cache memory. dont spare any expense for the cache memory. BTW, ive run them on AlphaLinux with the 164LX boards and SRM bioses. works great. A 21264 Alpha, a gig of RAM with a ICP Vortex card and 256 Megs of ECC cache on the card connected to an 8 drive arra cant be beat.

Re:What about ATA RAID 5?

[Chronoforge]

Actually, 3ware has reversed their decision, and is again selling the IDE RAID cards.

Controllers? Who need controllers?

[Sxooter]

There are three great options to get your servers out of the RAID-controller business. One is NAS (Network Attached Storage), the second is using native SCSI or IDE controllers with RAID provided by your OS. And lastly, you can buy a box that already is a RAID but just looks like one big fat drive and plug it in.

At work run all our linux boxen at work with kernel mirroring and it uses almost NO CPU even under pretty heavy parallel load. Great for the base OS with SCSI or IDE, since the only thing they'll do once they boot is swap to these. Striping your swap space across multiple drives really helps when a server starts running low on memory.

I have mirror sets running at 48 Megabytes a second on two year old 18 Gig 10k SCSI drives for streaming output, and can provide very good performance under parallel load as a database disk set.

I've never had the kernel RAID drivers act flakey since I started using them over two years ago, and I've done various things like hot insert a raid disk in both RAID 1 and RAID 5 (both were pretty easy to do.) and typed the respected, yet undocumented --really-xxxxx (xxxxx=a 5 letter word not mentioned here!) flag a few times.

A friend is in the process of building NAS servers in 2U units with multiple IDE cards and ~500 Gigs of storage for ~$3500 or so. SCSI versions would be a bit more, bigger, and probably need more cooling, but be faster too. Right now the IDE ones are fast enough with a RAID 5 configuration.

The IDE ones can flood a 100 Base-TX connection, so performance isn't really an issue for anything on less than gigabit, and even then the IDEs will use up a goodly chunk of that.

The external RAIDS are often the fastest for databases, offering fibre optic connections. they're not cheap, but if you're running EBay's database, cheap isn't the point anymore. :-)

If you have to have a RAID card, I can recommend the AMI Megaraid 428, which used, on Ebay, goes for $100 right now. Not that fast (I never got more than 20 Megabytes a second from one) but very solid and reliable, and they can hold up to 45 SCSI hard drives if you can afford the cooling and electrical for them. Plus the first channel looks like a regular SCSI card to anything other than a hard drive, like a tape drive or CDROM, so you don't need another SCSI card if you want a tape drive to back it up.

While the Megaraid site no longer has configuration software available, this site:

http://domsch.com/linux/#megaraid

points to this site:

http://support.dell.com/us/en/filelib/download/i nd ex.asp?fileid=R28825

on Dell where you can find management software for the MegaRAID controllers.