An eternal challenge with home file servers connected to MythTV systems is disk space. Any new space is typically consumed within months.
About eight months ago, while dealing with space issues, I researched all the hardware raid solutions under $1000 on the market. Generally, the reviews tended to lean in the direction of 3Ware products. Unfortunately, they were all SATA & PCIe solutions meaning I would have to completely upgrade my server system. That meant a new PCIe motherboard, processor, RAM, and case for about $500, and the 3Ware 9650SE for another $500, plus new drives, about $1000. That’s a $2000 system. I just couldn’t lay that cash out at the time so I stalled.
Weekly I would evaluate my position to see if I could buy the system. After Christmas, it was clear that I had to do something. So I bought all the gear from Newegg.
Setting up the system was a piece of cake. Everything installed easily and came up the first time. I had three 750GB drives, one with 750GB of data that I needed to save. So I configured the two 750’s in a RAID 0 configuration with the intention of copying the data from the third 750 to it, then migrating to a RAID 5 configuration.
Big mistake. The migration on this state of the art machine was taking forever. The math led to the migration taking over 120 hours. I called 3Ware support and they said that’s normal and expected: it’s all good. That’s a data migration rate of 3 MB/s putting it in the MFM hard drive range. (That’s from the 80286 era… back in the mid ’80s)
OK fine, I’ll migrate rarely. Good enough. I’ll back the data up again to another drive, build a RAID 5 array from the get go and be on my way.
After running through the hoops and getting the system built and closed up, I realize that it’s now _very_ slow. Like, it takes seven seconds to return from running ls on the root folder. I googled around and discovered others having the same problem.
After some diagnosis, I discovered the problem. Building a RAID 0 array with the on board write cache on or off was __really__ fast. On the order of 180MB/s write speed. Glorious really. Moving to RAID 5 without the on board cache brought write speeds to less than 9 MB/s. Abhorrent. Turning the cache back on sped things up a bit.
A quick call to 3Ware tech support confirmed the numbers.
So there you have it. A state of the art machine with a $500 hard drive controller card on a 4x PCIe bus and 300MB/s SATA drives gives write speeds resembling that of my Amiga back in the 80’s.
3Ware’s position is to get the battery backup and enable the cache which is a $150 option. Unacceptable, as any modern dedicated RAID card should be able to sustain a 20MB/s write rate without cache.
One could run a RAID 5 configuration with write cache and without a battery backup, but if the power fails, power supply fails, or system crashes, you’ve lost everything.
The whole thing was unacceptable and very disappointing. I’d been looking forward to owning this card for months and now I’m returning it after investing months saving/planning and weeks of testing. The card, specially selected motherboard and CPU all went back to Newegg for a full refund. Newegg’s one of the best online stores I’ve worked with. Buy from them.
Price/Value, the 3Ware 9650se was one of the worst electronic products I’ve ever purchased.
Soon, I’ll post the solution to this whole mess.