On 18 Feb 2009 at 8:44, Erez Zilber wrote: > > On Tue, Feb 17, 2009 at 11:35 PM, Mike Christie <micha...@cs.wisc.edu> wrote: > > > > Erez Zilber wrote: > >> Hi, > >> > >> I'm running a setup of open-iscsi connected to a target. When I run > >> I/O from the initiator (e.g using dd) with transaction size of 128kB, > >> I sometimes see that 2 128kB requests are aggregated to a single 256kB > >> request. This is rare, but it happens from time to time. Can I disable > >> this feature? Who is responsible for that? Is it scsi-ml? > >> > > > > block layer. > > > > /sys/block/sdX/queue/max_sectors_kb > > Thanks, but this will limit the I/O size for all I/Os. What I forgot > to mention is that sometimes I also send larger I/Os (e.g. 512kB). > With the proposed solution, these large I/Os will be sent as multiple > 128kB I/Os (and affect the performance). Isn't there a way to simply > avoid this aggregation?
Hi! May I curiously ask why you would want that at all? In my experience, the larger the requests, and the more requests are packed into one packet, the better the performance. 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 -~----------~----~----~----~------~----~------~--~---
