On 22 Dec 2008 at 5:11, Eric wrote: > Besides that, I don't think I totally agree on your statement. Letting > the IO scheduler taking the actual disk geometry into account, should > give more performance. However, the fdisk default values are probably > standard for disks these days.
The disk scheduler can safely assume that contiguous nearby "forward" requests perform better than small scattered "backwards" requests. All other is mostly speculative IMHO. You would have to know about the heads position relative in time, track skew, sector skew, etc. Today's disk have cache big enough for whole tracks, so the scheduler shouldn't really care about sectors. Also the scheduler really cannot know on which physical cylinder (or track, or head) a specific block will actually reside. However when we are talking about problems in the scheduler _software_ you may be right. I didn't look into it for years ;-) Regards, Ulrich --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~----------~----~----~----~------~----~------~--~---
