On Fri, Apr 03, 2015 at 05:39:32PM -0400, Gene Heskett wrote: > Usually less than 4 megabytes of free space left at the end of the disk > with a used 4k per sector disk on the cable, but could be zero for a 512 > byte per sector used disk since there is not normally an alignment > problem with the old 512 byte per sector formatting. I have 1Tb disks > that look alike at first glance. The 512 byte per sector pair is > heavier and a wee bit thicker because it likely has two platters in it, > while the 4k version pair is a bit lighter and thinner, I presume > because there is only one platter in those two disks. > > The commodity drives I have coming will be, at 2Tb, 4096 bytes per > sector, and linux must align its writes with a Read-Modify-Write cycle > updating the whole 4k just to change one byte if things don't start on a > sector boundary. There's a pretty good speed penalty for doing that. A > disk that can write at 120+ megs a second when aligned can be turned > into a 20 megs a second slowpoke. if miss-aligned.
Ahh!, weren't you mentioning performance problems? There was a recent discussion on the netbsd-users list about 4k disks. In particular this: http://mail-index.NetBSD.org/netbsd-users/2015/03/27/msg015986.html -- "If you're not careful, the newspapers will have you hating the people who are being oppressed, and loving the people who are doing the oppressing." --- Malcolm X -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/20150404002217.GA433@tal
