If the IRQ16 is being used by your iSCSI driver, then yeah, that could cause all sorts of slow-downs. Modern 10GbE should be using MSI or MSI-X and not sharing interrupts.
Shared interrupts can be problematic because a highly active device (USB isochronous devices for example) can actually *starve* another device. Normally prioritization of interrupts means that this isn’t a big deal, but with the interrupt levels being different, this means a relatively low priority device can starve a higher priority one. Bad juju. Take a look at mdb ::interrupts output, to see how your interrupts are being used. If this is indeed the issue, we can then explore options to correct this via BIOS or driver tuning. That said, it’s too early to blame this with certainty on your slowdowns. There could be other issues, like caching, disk retry issues (bad blocks, etc.) or even underlying ZFS issues. Differences in caching strategy between your NFS and iSCSI shares mean that underlying physical/target problems can exhibit very differently in terms of perceived performance. On Tue, Oct 3, 2017 at 7:52 AM Gabriele Bulfon <[email protected]> wrote: > Hi, > > we're testing the Supermicro AOC-STGN-i2S SFP+, chipset Intel® 82599EN > 10GbE controller / Intel 82599ES 10GbE, using recent illumos kernel on > XStreamOS. > > We're experiencing a strong slow down when sharing over iSCSI compared to > sharing over NFS. > Same hardware, same route, same vmware machine connecting two datastores, > one over iSCSI and one over NFS. > Same file copied over from a local vmware disk to the connected datastore, > takes 20-30 times more over iSCSI. > We never experienced this in the past with older hardware, NFS used to be > always a little bit slower instead. > > I noticed this on messages: > > NOTICE: IRQ16 is being shared by drivers with different interrupt levels. > > Any idea? > > Gabriele > > *Sonicle S.r.l. *: http://www.sonicle.com > *Music: *http://www.gabrielebulfon.com > *Quantum Mechanics : *http://www.cdbaby.com/cd/gabrielebulfon > *illumos-discuss* | Archives > <https://illumos.topicbox.com/groups/discuss/discussions/Te3cd054be76d039d-M723edcaaec04088fadb1a047> > | Powered by Topicbox <https://topicbox.com> ------------------------------------------ illumos-discuss Archives: https://illumos.topicbox.com/groups/discuss/discussions/Te3cd054be76d039d-Mbe2cd0c4df85528267408fba Powered by Topicbox: https://topicbox.com
