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

Mylex controllers are junk

[krow]

I would blame a really large portion of Slashdot's downtime, and the recent downtime with Freshmeat, on those controllers. Outside of a Megadrive that I used at the Virtual Hospital, those are probably some of the worst pieces of Hardware I have ever ran into.
I would never recommend that anyone ever use those cards. Flaky hardware is one issue, but those cards have consistently been the root of a lot of sleepless nights for me fixing the mess that they have caused.

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.

Re:SCSI is DEAD

[GiMP]

So what is replacing it? I know you did not just suggest that IDE is actually worth anything.

I would really like to see you run servers on IDE.. HaHa. You are not just a troll, but a stupid one.

SCSI will not die any time soon. If it does, it will be replaced by Fibre Channel.. You couldn't pay me to use an IDE disk anymore, except maybe to boot legacy (x86) hardware with so I can boot from an NFS sever.. for a workstation.

For a server, IDE has no place. Half-duplex, cpu intensive, unreliable, do I need to say more? Oh, and incrediably limited in the number of disks. Raid5 array of IDE? yeah right. You can only have 8 IDE disks in a system, all of which use interrupts.

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.

What about ATA RAID 5?

[dschuetz]

Does anyone have any thoughts about IDE raid, especially the offerings from Promise Technology? They've got cards that do RAID 5 with regular IDE drives, including hot failover capability. They've also got subsystems that put a full 8 disks into a RAID array, but presents it to the controller as a single SCSI device.

Advantages: Cheap drives.
Disadvantages: Speed, maybe, though since it's all going directly into the PCI bus, I'm not sure this is an issue.

Anyone used these? Comments? I figure with their SuperTrax controller and a bunch of 80 or 100-G drives, you could have half a terabyte in your basement for under two grand.

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: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.