On 8 Feb 2010, at 11:48, Tim Small wrote: > ... it's possible that there are genuine > reasons for this - I spent/wasted most of last week diagnosing what is > starting to look like a firmware bug on WD 2TB "green power" drives > on a > non-Dell server ... > > I wouldn't be surprised if the H700 adaptor firmwares are doing > various > "unusual" things to the hard drives, and it's possible that Dell has > got > nervous about buggy firmware from unqualified drives reflecting > badly on > their hardware.....
There's a thread on gentoo-user which I have just now seen come to conclusions regarding modern drives with 4K sector sizes ("1-Terabyte drives - 4K sector sizes? -> bar performance so far") It appears that AIUI fdisk will, by default, create partitions out of optimal alignment for these modern drives. My understanding of this is a little sketchy - I *think* I'm understanding correctly, but I beg forgiveness if I explain wrong. The first partition created by fdisk will, by default, start at sector 63, as shown by `echo p | sudo fdisk -u /dev/sdb`. Two users in that thread report that creating the partition manually to start at sector 64 will, on large modern drives with 4K sector sizes, increase performance by a couple of orders of magnitude, "to roughly 20 seconds from 8-10 minutes". I believe cfdisk may also by default create its first partition beginning at sector 63, as I'm seeing that on one of my systems here and I tend to use cfdisk for partitioning. Apparently Windows, since Vista, at least, does not suffer this problem, and already aligns partitions optimally by default. So it would be quite cool if Dell's firmware specially compensated for this for the benefit of Linux users. If this were the reason (and actually I suspect that it is not) then the firmware should squawk about 3rd-party drives, rather than rejecting them outright, as already agreed by everyone posting to this thread. Stroller. _______________________________________________ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq