Dependable SCSI RAID Controllers for Linux? 63
"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."
AMI sold the Megaraid divison to LSI (Score:2, Informative)
never had any problems with it whatsoever.
IBM ServeRaid (Score:3, Informative)
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 (Score:3, Informative)
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 (Score:4, Informative)
Re:Mylex controllers are junk (Score:3, Informative)
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 (Score:2, Informative)
Re:Compaq (Score:3, Informative)
The SmartArray works great. The little lights now light up on the drives (ya know, green, yellow and "uh-oh"). Heh.
ICP Vortex (Score:2, Informative)
Great cards, great speed, and a not so bad price. They work flawlessly in Linux and Windows.
Re:ICP Vortex (Score:3, Informative)
Re:What about ATA RAID 5? (Score:2, Informative)
Controllers? Who need controllers? (Score:2, Informative)
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/
on Dell where you can find management software for the MegaRAID controllers.