> -----Original Message----- > From: Vivek Goyal [mailto:vgoyal@xxxxxxxxxx] > Sent: Tuesday, March 29, 2011 1:34 PM > To: Iyer, Shyam > Cc: rwheeler@xxxxxxxxxx; James.Bottomley@xxxxxxxxxxxxxxxxxxxxx; > lsf@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; dm- > devel@xxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx > Subject: Re: [Lsf] Preliminary Agenda and Activities for LSF > > On Tue, Mar 29, 2011 at 10:20:57AM -0700, Shyam_Iyer@xxxxxxxx wrote: > > > > > > > -----Original Message----- > > > From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi- > > > owner@xxxxxxxxxxxxxxx] On Behalf Of Ric Wheeler > > > Sent: Tuesday, March 29, 2011 7:17 AM > > > To: James Bottomley > > > Cc: lsf@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-fsdevel; linux- > > > scsi@xxxxxxxxxxxxxxx; device-mapper development > > > Subject: Re: [Lsf] Preliminary Agenda and Activities for LSF > > > > > > On 03/29/2011 12:36 AM, James Bottomley wrote: > > > > Hi All, > > > > > > > > Since LSF is less than a week away, the programme committee put > > > together > > > > a just in time preliminary agenda for LSF. As you can see there > is > > > > still plenty of empty space, which you can make suggestions (to > this > > > > list with appropriate general list cc's) for filling: > > > > > > > > > > > > https://spreadsheets.google.com/pub?hl=en&hl=en&key=0AiQMl7GcVa7OdFdNQz > > > M5UDRXUnVEbHlYVmZUVHQ2amc&output=html > > > > > > > > If you don't make suggestions, the programme committee will feel > > > > empowered to make arbitrary assignments based on your topic and > > > attendee > > > > email requests ... > > > > > > > > We're still not quite sure what rooms we will have at the Kabuki, > but > > > > we'll add them to the spreadsheet when we know (they should be > close > > > to > > > > each other). > > > > > > > > The spreadsheet above also gives contact information for all the > > > > attendees and the programme committee. > > > > > > > > Yours, > > > > > > > > James Bottomley > > > > on behalf of LSF/MM Programme Committee > > > > > > > > > > Here are a few topic ideas: > > > > > > (1) The first topic that might span IO & FS tracks (or just pull > in > > > device > > > mapper people to an FS track) could be adding new commands that > would > > > allow > > > users to grow/shrink/etc file systems in a generic way. The > thought I > > > had was > > > that we have a reasonable model that we could reuse for these new > > > commands like > > > mount and mount.fs or fsck and fsck.fs. With btrfs coming down the > > > road, it > > > could be nice to identify exactly what common operations users want > to > > > do and > > > agree on how to implement them. Alasdair pointed out in the > upstream > > > thread that > > > we had a prototype here in fsadm. > > > > > > (2) Very high speed, low latency SSD devices and testing. Have we > > > settled on the > > > need for these devices to all have block level drivers? For S-ATA > or > > > SAS > > > devices, are there known performance issues that require > enhancements > > > in > > > somewhere in the stack? > > > > > > (3) The union mount versus overlayfs debate - pros and cons. What > each > > > do well, > > > what needs doing. Do we want/need both upstream? (Maybe this can > get 10 > > > minutes > > > in Al's VFS session?) > > > > > > Thanks! > > > > > > Ric > > > > A few others that I think may span across I/O, Block fs..layers. > > > > 1) Dm-thinp target vs File system thin profile vs block map based > thin/trim profile. > > > Facilitate I/O throttling for thin/trimmable storage. Online and > Offline profil. > > Is above any different from block IO throttling we have got for block > devices? > Yes.. so the throttling would be capacity based.. when the storage array wants us to throttle the I/O. Depending on the event we may keep getting space allocation write protect check conditions for writes until a user intervenes to stop I/O. > > 2) Interfaces for SCSI, Ethernet/*transport configuration parameters > floating around in sysfs, procfs. Architecting guidelines for accepting > patches for hybrid devices. > > 3) DM snapshot vs FS snapshots vs H/W snapshots. There is room for > all and they have to help each other For instance if you took a DM snapshot and the storage sent a check condition to the original dm device I am not sure if the DM snapshot would get one too.. If you had a scenario of taking H/W snapshot of an entire pool and decide to delete the individual DM snapshots the H/W snapshot would be inconsistent. The blocks being managed by a DM-device would have moved (SCSI referrals). I believe Hannes is working on the referrals piece.. > > 4) B/W control - VM->DM->Block->Ethernet->Switch->Storage. Pick your > subsystem and there are many non-cooperating B/W control constructs in > each subsystem. > > Above is pretty generic. Do you have specific needs/ideas/concerns? > > Thanks > Vivek Yes.. if I limited by Ethernet b/w to 40% I don't need to limit I/O b/w via cgroups. Such bandwidth manipulations are network switch driven and cgroups never take care of these events from the Ethernet driver. The TC classes route the network I/O to multiqueue groups and so theoretically you could have block queues 1:1 with the number of network multiqueues.. -Shyam -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
