On Fri, 10 Dec 2004 06:02:00 -0600, Ewan Grantham <ewan.grantham@xxxxxxxxx> wrote: > Have a 4-disk RAID 5 array of 250Gig HDs that I am looking to use for > performing video capture and editing. Two of the disks are internal, > and two are external and connected using a USB2 card. Running under a > Debian installation with a 2.4.27 kernel, I can capture for a few > minutes, but then I start to drop frames, and the percentage dropped > gets worse as time goes on. Well, I got my answer by using a second card and moving to kernel 2.6.7 - sort of. Put in the second card, and it showed up in usbview, but the disk attached to it showed up as being attached to an "unknown" usb hub at only 1.1 speed. Figured this might be a 2.4 kernel issue (with USB), and so rebooted into kernel 2.6.7. Nope, the second card still showed up "funny". However I had somehow convinced it to load ehci-hcd (had not been able to do that before) and so the first disk was running at Hi Speed. Just for grins I pulled the second drive off the second card, and plugged it back into the first card. Now both disks were showing hi speed. Having read that the USB drivers for kernel 2.6 were more "efficient", I decided to see what would happen. Sure enough, I can now capture (at least 30 minutes) without a single dropped frame. So, adding a second card evidently did "fix" the problem, just not directly :-) Guess this means RAID-5 under a 2.6.7 kernel is possible using USB. I'd still "ideally" like to use the second USB card, but with it running so well I'm a little disinclined to touch anything at this point... FWIW, Ewan - 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
