Hi, I had to realize this week that my VMs on Citrix XenServer are very slow, compared to Linux.
I’m getting maybe 8 or 10 MB/s, wheres an Ubuntu 14 guest gets 110+ MB/s (Megabyte). Independent of the filesystem, just wiping the disks with dc3dd. This went unnoticed, because not much I/O is done in these VMs. But recently, a customer complained and I had to look into it. The VM is running stock 10.3-RELEASE-p6. The OS-type is set to FreeBSD 10 64 bit. Same thing happens with FreeBSD 11-RC1. This is what I get in 11-RC1 from sysctl: (freebsd11 </root>) 0 # sysctl -a |grep xen kern.vm_guest: xen device xenpci vfs.pfs.vncache.maxentries: 0 dev.xenbusb_back.0.%parent: xenstore0 dev.xenbusb_back.0.%pnpinfo: dev.xenbusb_back.0.%location: dev.xenbusb_back.0.%driver: xenbusb_back dev.xenbusb_back.0.%desc: Xen Backend Devices dev.xenbusb_back.%parent: dev.xn.0.xenstore_peer_path: /local/domain/0/backend/vif/245/0 dev.xn.0.xenbus_peer_domid: 0 dev.xn.0.xenbus_connection_state: Connected dev.xn.0.xenbus_dev_type: vif dev.xn.0.xenstore_path: device/vif/0 dev.xn.0.%parent: xenbusb_front0 dev.xbd.1.xenstore_peer_path: /local/domain/0/backend/vbd3/245/768 dev.xbd.1.xenbus_peer_domid: 0 dev.xbd.1.xenbus_connection_state: Connected dev.xbd.1.xenbus_dev_type: vbd dev.xbd.1.xenstore_path: device/vbd/768 dev.xbd.1.%parent: xenbusb_front0 dev.xbd.0.xenstore_peer_path: /local/domain/0/backend/vbd3/245/832 dev.xbd.0.xenbus_peer_domid: 0 dev.xbd.0.xenbus_connection_state: Connected dev.xbd.0.xenbus_dev_type: vbd dev.xbd.0.xenstore_path: device/vbd/832 dev.xbd.0.%parent: xenbusb_front0 dev.xenbusb_front.0.%parent: xenstore0 dev.xenbusb_front.0.%pnpinfo: dev.xenbusb_front.0.%location: dev.xenbusb_front.0.%driver: xenbusb_front dev.xenbusb_front.0.%desc: Xen Frontend Devices dev.xenbusb_front.%parent: dev.xs_dev.0.%parent: xenstore0 dev.xctrl.0.%parent: xenstore0 dev.xenballoon.0.%parent: xenstore0 dev.xenballoon.0.%pnpinfo: dev.xenballoon.0.%location: dev.xenballoon.0.%driver: xenballoon dev.xenballoon.0.%desc: Xen Balloon Device dev.xenballoon.%parent: dev.debug.0.%parent: xenpv0 dev.privcmd.0.%parent: xenpv0 dev.evtchn.0.%parent: xenpv0 dev.xenstore.0.%parent: xenpv0 dev.xenstore.0.%pnpinfo: dev.xenstore.0.%location: dev.xenstore.0.%driver: xenstore dev.xenstore.0.%desc: XenStore dev.xenstore.%parent: dev.xen_et.0.%parent: xenpv0 dev.xen_et.0.%pnpinfo: dev.xen_et.0.%location: dev.xen_et.0.%driver: xen_et dev.xen_et.0.%desc: Xen PV Clock dev.xen_et.%parent: dev.granttable.0.%parent: xenpv0 dev.xenpv.0.%parent: nexus0 dev.xenpv.0.%pnpinfo: dev.xenpv.0.%location: dev.xenpv.0.%driver: xenpv dev.xenpv.0.%desc: Xen PV bus dev.xenpv.%parent: dev.xenpci.0.%parent: pci0 dev.xenpci.0.%pnpinfo: vendor=0x5853 device=0x0001 subvendor=0x5853 subdevice=0x0001 class=0x010000 dev.xenpci.0.%location: slot=3 function=0 dbsf=pci0:0:3:0 handle=\_SB_.PCI0.S18_ dev.xenpci.0.%driver: xenpci dev.xenpci.0.%desc: Xen Platform Device dev.xenpci.%parent: dev.xen.xsd_kva: 18446735281894703104 dev.xen.xsd_port: 3 dev.xen.balloon.high_mem: 0 dev.xen.balloon.low_mem: 0 dev.xen.balloon.hard_limit: 18446744073709551615 dev.xen.balloon.driver_pages: 0 dev.xen.balloon.target: 2097152 dev.xen.balloon.current: 2096128 I’ve tried switching the „OS Type“ to something like „other PV“ and get a bit more throughput. But nowhere near enough to make this useful. Over at freebsd-xen, Roger thinks it looks right from the FreeBSD-side. I’m not the administrator of the Xen-Server itself (it’s part of an Apache CloudStack private cloud cluster setup), but I can have pretty much any setting checked/tried I need. _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
