Re: (reiserfs) Re: More on 2.2.18pre2aa2 (summary of elevator ideas)
On 12 Sep 2000, at 18:08, Ed Tomlinson wrote: > Hi, > > I made the comment because I remember back when the discussion was current > on linux kernel. I thought Jeff Merkey's, message was to the point. Para- > phrasing from memory, it was something to the effect that novell had > tried many elevators. All had problems with some loads. The best they > had found was the 'close the door' idea. I do not remember if the door > was based on requests or time. Another point to remember is that the > netware people came up with a what they considered a good solution. I believe that the Netware elevator is based on outstanding requests. This is a tunable parameter which may be increased for fast disk subsystems. I think that you could consider the number of requests to be loosely related to time. That is, the time to service 50 requests should be fairly predictable for a given disk/controller. I don't think you need to time stamp every request to get good results. --Mailed via Pegasus 3.12 & Mercury 1.44--- [EMAIL PROTECTED]Fax (617)373-2942 Andrew Scott Tel (617)373-5278 _ Northeastern University--138 Meserve Hall / \ / College of Arts & Sciences-Deans Office / \ \ / Boston, Ma. 02115 / \_/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: (reiserfs) Re: More on 2.2.18pre2aa2 (summary of elevator ideas)
You're welcome. :-) Jeff Hans Reiser wrote: > > "Jeff V. Merkey" wrote: > > > > One important point on remirroring I did not mention in my post. In > > NetWare, remirroring scans the disk BACKWARDS (n0) to prevent > > artificial starvation while remirring is going on. This was another > > optimization we learned the hard way by trying numerous approaches to > > the problem. > > > > Jeff > > Interesting. Thanks Jeff. > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: (reiserfs) Re: More on 2.2.18pre2aa2 (summary of elevator ideas)
You're welcome. :-) Jeff Hans Reiser wrote: "Jeff V. Merkey" wrote: One important point on remirroring I did not mention in my post. In NetWare, remirroring scans the disk BACKWARDS (n0) to prevent artificial starvation while remirring is going on. This was another optimization we learned the hard way by trying numerous approaches to the problem. Jeff Interesting. Thanks Jeff. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
