John Robinson put forth on 1/2/2011 3:11 PM: > Please could someone suggest a cheap PCI-E SATA card with 4 internal ports? In your situation, going the PMP route may be a better choice. Read on. > I currently have 6 motherboard SATA ports and a 5-drive hot-swap > chassis, I am thinking of adding a second 5-drive hot-swap chassis to my > case and would need another 4 SATA ports to drive it. > > Other requirements: known to work with RHEL/CentOS 5 kernels, even if it > means installing a driver with DKMS or whatever. > > Doesn't have to be PCI-E x1 because I've a spare x8 (logical)/x16 > (physical) slot, but I don't know if anything cheap's going to be > anything other than PCI-E x1. v2.0 (5GT/s) would be nice though. Go with one or two of these SATA II port multipliers with 1 host interface and 5 drive interfaces--perfect for a 10 drive setup with two 5 drive cages. http://www.addonics.com/products/host_controller/ad5sapm.asp http://www.buy.com/prod/addonics-ad5sapm-serial-ata-controller-5-x-7-pin-serial-ata-300-serial/q/loc/101/213272437.html http://www.siliconimage.com/products/product.aspx?pid=32 If your mobo SATA ports support FIS based switching, this PMP will give you 5 SATA II drive ports. It doesn't use a PCI slot of any kind. No additional software required. No kernel driver issues. 300MB/s is sufficient for 5 drives in an mdraid setup isn't it? When I use these I remove the slot bracket and mount the PCB directly to my server chassis side wall using mobo type standoffs. You may need to drill a couple of holes in the chassis depending on where you decide to mount it. If you're not a mechanically inclined DIY type person, just use the supplied mounting bracket. This may deny access to an underlying PCI slot though. I prefer the more solid mount and having all slots available. Personally, were I in your shoes, how I would do this is to buy two of these so I'd have identical IO paths for all 10 drives in both cages, 5 on each PMP. Connect each PMP to a mobo SATA II connector (again, assuming you have mobo PMP/FIS support), leaving 4 mobo SATA ports free for other stuff. It'll run you $124 to do it this way, but it's so much cleaner than having an asymmetric setup of 5 dives on individual mobo ports and the other 5 running on one mobo port through the PMP, especially if you plan to have drives in each 5 drive cage within the same mdraid device. If your mobo ports don't support PMP/FIS switching, grab one of these for $40: http://www.newegg.com/Product/Product.aspx?Item=N82E16816124040 http://www.sybausa.com/productInfo.php?iid=979 SATA III PCIe 2.0 x1 500MB/s PMP FIS support http://www.marvell.com/products/storage/storage_system_solutions/sata_controllers_pc_consumer/6_gbs_sata_raid_controller_88se91xx_product_brief.pdf You're up to $165 now, and well worth it, esp if your mobo doesn't support PMP/FIS. Plug each PMP into this card. Each 5 drive cage will be on a dedicated IO path. This setup will provide a combined 500MB/s of bandwidth (PCIe x1 v2.0 limited) to the 10 disks which should be plenty for most applications. The driver for the Marvell chip is present in kernel 2.6.19 and later. Considering that 2.6.19 is like 6 years old, I'd hope your kernel is newer. It may be a little more money than you were planning on spending, but for little more than the cost of one hard drive, it's a really clean, no hassle solution that you'll be happy with for some time. One side benefit is you free up all 6 mobo SATA ports for other uses. Grab you a 40GB OCZ Vertex II for $100 off Newegg and plug it into one of the mobo ports for use as a boot, system, log, temp drive. I don't know your mobo model# or I'd have been able to give you more concrete advice. As someone else mentioned, some system boards don't like x1 cards being plugged into their x8/x16 slots. If this is the case, I sure hope your mobo SATA chip supports PMP/FIS, as any x4/x8 SATA card that will work in such a finicky board is going to cost well over $100 alone, and to get one that supports more than 4 drives will likely be $200 or more and will have 2 mini SAS 8087 connectors, which will drive your cable costs up. -- Stan -- 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
