On Friday December 2, dean-list-linux-raid@xxxxxxxxxx wrote: > On Thu, 1 Dec 2005, Neil Brown wrote: > > > What I would really like is a cheap (Well, not too expensive) board > > that had at least 100Meg of NVRAM which was addressable on the PCI > > buss, and an XOR and RAID-6 engine connected to the DMA engine. > > there's the mythical giga-byte i-ram ... i say mythical because i've seen > lots of reviews but haven't been able to find it for sale: > > http://www.giga-byte.com/Peripherals/Products/Products_GC-RAMDISK%20(Rev%201.1).htm > > the only problem with the i-ram is the lack of ecc (it could be > implemented in a software layer though). The lack of ECC is a real killer for any sort of raid/journalling application. You want your journal to be more-resilient to failure than your main array, not less. And the fact that the board presents like an IDE controller (if I read that right) means it is meant as fast-disk. Not as a generally useful board to do interesting things with :-( The idea of just providing memory slots that you plug your own memory into is certainly interesting. It would mean making just one board and the custom could choose how much memory they wanted to buy. (umem below may several different sizes). I wonder if it affects reliability at all... > > umem.com have what look like excellent boards but they seem unwilling to > sell in small quantities... > > http://umem.com/Umem_NVRAM_Cards.html I have two of these in two different servers... I must have got them at a time when small quantities weren't so unpalatable. They have full ECC, and even have a driver in kernel.org kernels (I had to convince them that GPL wasn't bad, but that wasn't too hard). The boards I got only presented a 64M (I think) window to the PCI buss, though I believe they have versions that present to whole of memory instead of just one window. One of these with built in xor and raid6 would be nice, but I'm not sure I could guarantee a big enough market for them to try convincing them to make one... NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
