Sunday, December 5, 2010

Danger with Dell's H700 RAID card and FreeBSD 8.1-9.0

My new Dell PowerEdge T710 came with a fairly decent Dell PERC RAID card - the H700 with 512M of battery backed cache. It's a LSI 2108 based solution, and was providing far better performance than their older PERC5 or PERC6 solutions. It is even 6.0 G/s.

However - It's still a Dell RAID card, which are known for their slow speed. What do you expect, they need to protect their profit margins. :-)

Slow speed was something I was prepared to deal with - but that wasn't my issue; Specifically, I could never get a stable system using the mirrors I made with the H700.

It would be between a day or a few hours, and I'd start to see device timeout errors popping up on the console for one of the RAID mirror devices. I knew something was up, because my NFS connection to this box would die.

Oddly enough, the FreeBSD system was up, responsive, and I could browse the directories. I could not for the life of me get ESX to see my NFS shares on this box anymore. It didn't matter what services I restarted, it was down.

A reboot, and everything would be fine, until the next set of errors on the console.  Very frustrating as you can imagine.

After some research, I've found that the LSI drivers are not the best in FreeBSD due to corporate disclosure issues. I found this to be a shame, as I've loved LSI products for years in a Windows environment, and have even used their older chipsets without issue in FreeBSD as well.

If LSI would work with the open source community a bit more, maybe we'd be have a stable driver for it. At this stage, I'd say it's not a good idea in a production FreeBSD box.

So I needed a new brand to depend on, and this time around I was going to choose a company that had solid FreeBSD support.

Research returned good opinions about the Areca brand controllers. Not only are they often on the top of the benchmarks between other brands of RAID card, but they have native FreeBSD drivers - Source or compiled kernel lodable.

I dove in a purchased an Areca1880ix-12, shown below.
It may be a bit of overkill, but this thing can be expanded to 4 gig of RAM, has a dedicated RJ-45 port in the back for full web management, and it's currently on the top of the SAS 6.0 RAID HBA speed charts.

I also really like the 4 SAS 6.0 ports. I'll explain why in a future blog article when I detail my SAN build.

After a month of running this card, I've yet to have an odd panic, disk issue, or other crash with my SAN. It's rock solid with no complaints.

It's been so long, that I don't even have the logs of the original error message that the H700 would throw.. sorry.. but you'll see it if you hook one up with FreeBSD. :-)

If anyone gets a H700 running cleanly with a RAID mirror, let me know. I still have my H700, it's destined for ebay or possibly a spare for a Windows only box.

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