Topic: IDE raid cards

[Gerald Jansen]

Has anyone gotten the Promise or Startech IDE raid cards to work with 4.1.2? I have tried a number of different approaches. I have started with a fresh install of 4.1.2 and then mirrored the drive using the card bios driven code. This creates a mirror. However, e-smith then hangs after the initial splash screen. I then attempted to do a fresh load from scratch with the drives already in mirrored mode. This resulted in e-smith not recognizing the drives at all. The ARCO "Duplidisk" works fawlessly. However it uses different approach, The ARCO card uses the motherboard IDE controller  and then its own processor to write to the primary and mirrored drive. This makes the device totally transparent to any operating system. Problem with the ARCO card is cost, it is about $230.00 US and has very small reseller discounts. The Promise and Startech PCIIDE cards both wholesale for about $80.00. Quite a difference, so there is incentive to find a way to make them work.  TIA for any comments or ideas

[Dan Brown]

I understand that the 3ware IDE RAID cards are supported out of the box, and a 2-port card from them runs about $120 (retail via pricewatch).  The cheaper promise cards are really just IDE controllers; it's the drivers that make them do RAID, and I don't know of any good way to make e-smith grok the drivers (they're supported in RedHat 7.1, but not 7.0, IIRC).

If all you're going to get is software RAID anyway (which is what you get with the promise card), you might as well skip it and use e-smith's software RAID 1.

I recently read a review on storagereview.com which compared a 3ware 4-port controller to one of the higher-end promise units.  The 3ware wiped the floor with the promise, especially in RAID 0.

[jose velez]

I have use both the ARCO and 3Ware and ARCO performance is the best.  3Ware card performance was very slow.  The arco is hardware and Ghost works with it.  3ware card requires driver from the OS to work.

[Dan Brown]

I haven't used either card; I only know what I've read about them.  That said, if the ARCO unit is as transparent as they say it is, there's no reason it shouldn't work with Linux (or anything else, as they claim).  OTOH, you're never going to see a performance improvement over your on-board IDE controller with the ARCO unit, and the DupliDisk II PCI costs about $100 more than the two-port 3Ware unit, or about the same as the 4-port.

I can't argue against your experience of the 3ware card being slower than the ARCO, but the folks at StorageReview found it to be about 60% faster than a single drive for read performance in RAID 1 mode.  See the review at http://www.storagereview.com/articles/200102/20010214ST1000_vs_Escalade_1.html for all the details.

For about the same money as the DupliDisk II PCI, you could buy a 3ware 6400.  The DDII will support two mirrored pairs.  The 6400 can do that, but it can also stripe them (RAID 10) for a significant performance improvement, build the same four drives into a 3-drive RAID 5 array with a hot spare and the same storage capacity, or use them in a 4-drive RAID 5 array with a 50% increase in capacity.  Or, if you didn't care about fault-tolerance, you could set up a RAID 0 across all 4 drives and have very fast storage indeed.

Further, the 3ware card supports hot spares, hot swapping, and doesn't require rebooting the computer from a utility disk to configure the array(s).

Yes, the 3ware card requires a driver.  So what?  So does any other real drive controller, including the IDE controller on your motherboard.  The ARCO just uses that driver.  The driver is included with e-smith (and also, IIRC, ships with the card), and the card includes drivers for just about any flavor of Windoze you'd want.

All of this said, I don't work for 3ware; I don't even own one of their cards (at least, not yet).  I just don't see the ARCO unit as a real competitor to the 3ware.