Changes

Starting with GlusterFS 3.4.0 there is a an API which can be used to access files on a GlusterFS volume directly without the FUSE-mount. Qemu supports this , starting from with version 1.23.0.

To achieve that, add the following line to the <code>volume management</code> in <code>/etc/glusterfs/glusterd.vol</code> on all involved storage nodes and restart glusterd:

gluster volume set virtualization server.allow-insecure On</pre> After that you should at least restart <code>glusterd</code>:<pre>/etc/init.d/glusterd restart</pre> But it seems that one also has to restart all <code>glusterfsd</code> daemons by restarting the volume. So, do the following ona GlusterFS node:<pre>gluster volume stop virtualizationgluster volume start virtualization

The XML has to be changed only slightly. Following is an example:.

'''current'''<presyntaxhighlight lang='xml'> <disk type='file' device='disk'> <driver name='qemu' type='qcow2' cache='none'/> <source file='/var/virtualization/vm-templates/5b77d2f6-061f-410c-8ee7-9e61da6f1927/f3d87cf9-f7d8-4224-b908-cc9fc6c8fcd4.qcow2'/> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </disk></syntaxhighlight> '''direct-gluster-access'''<syntaxhighlight lang='xml'>

<driver name='qemu' type='qcow2' cache='none'/>

;<codepre>diskfoss-type<cloud-node-01 ~ # qemu-img create -f qcow2 gluster:/code>/10.1.120.11/virtualization/foo.qcow2 20GFormatting 'gluster:has to be <code>network</code> instead of <code>/10.1.120.11/virtualization/foo.qcow2', fmt=qcow2 size=21474836480 encryption=off cluster_size=65536 lazy_refcounts=off foss-cloud-node-01 ~ # stat /var/virtualization/foo.qcow2 File: ‘/var/virtualization/foo.qcow2’ Size: 197120 Blocks: 385 IO Block: 131072 regular file<Device: 1ch/code>28d Inode: 11101537565691465327 Links: 1Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root)Access: 2013-08-04 07:37:01.814422718 +0200Modify: 2013-08-04 08:31:51.968884606 +0200Change: 2013-08-04 08:31:51.968884606 +0200 Birth: -;<code>source</codepre>:has now a  == qemu == The following qemu commandline is generated by libvirt, minus the network device, the <code>protocol-S</code> parameter and with disabled spice password and should give a running VM, given that the specified VM images exist: <codepre>/usr/bin/qemu-system-x86_64 \ -machine accel=kvm \ -name<e35422fa-18e7-41eb-8478-d09daff1b43a \ -machine pc-1.3,accel=kvm,usb=off \ -m 2048 \ -realtime mlock=off \ -smp 1,sockets=1,cores=1,threads=1 \ -uuid e35422fa-18e7-41eb-8478-d09daff1b43a \ -no-user-config \ -nodefaults \ -chardev socket,id=charmonitor,path=/code> instead of a <code>var/lib/libvirt/qemu/e35422fa-18e7-41eb-8478-d09daff1b43a.monitor,server,nowait \ -mon chardev=charmonitor,id=monitor,mode=control \ -rtc base=utc \ -no-shutdown \ -device ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x8.0x7 \ -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x8 \ -device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x8.0x1 \ -device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x8.0x2 \ -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 \ -drive file=gluster://10.1.120.11/virtualization/iso/a51f5193-f518-4cb6-8d5b-f24538543217.iso,if=none,id=drive-ide0-0-1,readonly=on,format=raw \ -device ide-cd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 \ -drive file=gluster://10.1.120.11/virtualization/vm-templates/5b77d2f6-061f-410c-8ee7-9e61da6f1927/f3d87cf9-f7d8-4224-b908-cc9fc6c8fcd4.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none \ -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x6,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \ -chardev spicevmc,id=charchannel0,name=vdagent \ -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0 \ -device usb-tablet,id=input0 \ -spice port=5900,addr=192.168.140.13,seamless-migration=on,disable-ticketing \ -vga qxl \ -global qxl-vga.ram_size=67108864 \ -global qxl-vga.vram_size=67108864 \ -device AC97,id=sound0,bus=pci.0,addr=0x4 \ -chardev spicevmc,id=charredir0,name=usbredir \ -device usb-redir,chardev=charredir0,id=redir0,filter=-1:-1:-1:-1:0 \ -chardev spicevmc,id=charredir1,name=usbredir \ -device usb-redir,chardev=charredir1,id=redir1,filter=-1:-1:-1:-1:0 \ -chardev spicevmc,id=charredir2,name=usbredir \ -device usb-redir,chardev=charredir2,id=redir2,filter=-1:-1:-1:-1:0 \ -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7</codepre> attribute as well as a new subelement  = Troubleshooting = == Qemu hang == Should Qemu hang after start, check the brick logfile (in our default setup this would be <code>host/var/log/glusterfs/bricks/var-data-gluster-volume-01.log</code>, where ) for the following entries:<codepre>name[2013-08-04 11:02:34.022328] E [addr.c:152:gf_auth] 0-auth/addr: client is bound to port 50037 which is not privileged[2013-08-04 11:02:34.022362] E [authenticate.c:239:gf_authenticate] 0-auth: no authentication module is interested in accepting remote-client (null)[2013-08-04 11:02:34.022410] E [server-handshake.c:578:server_setvolume] 0-virtualization-server: Cannot authenticate client from foss-cloud-node-01-12502-2013/08/04-11:02:33:989625-virtualization-client-1-0 3.4.0</codepre> is This means that one of the filename without configuration options from above didn't work and/or you forgot to restart <code>/var/glusterd</code>or the volume. = Caveats = == Number of GlusterFS servers == At the moment it is not possible to specify more than one server. == libvirt integration == Libvirt is supposed to be able to create images on a GlusterFS. But a storage pool must be set up first with the appropriate configuration.