Forwarded to centos mailing list -----Original Messages----- From: wuzhouhui <wuzhouhui14 at mails.ucas.ac.cn> Sent Time: 2018-10-30 14:06:00 (Tuesday) To: "storage performance development kit" <spdk at lists.01.org> Cc: centos at centos.org, qemu-discuss at nongnu.org Subject: Re: [SPDK] VM boot failed sometimes if using vhost-user-blk with spdk I enable debug of systemd-udevd by changing guest's /etc/udev/udev.conf to this: udev_log="debug" and regenerate initramfs. Then, we can get more message about this issue. I select some useful messages from /run/initramfs/rdsosreport.txt: systemd-udevd[199] probe /dev/vdb raid offset=8 systemd-udevd[199] no db file to read /run/udev/data/+virtio:virtio1: No such systemd-udevd[199] handling device node '/dev/vdb', devnum=b253:16, mode=0660, systemd-udevd[199] set permissions /dev/vdb, 060660, uid=0, gid=6 systemd-udevd[199] creating symlink '/dev/block/253:16' to '../vdb' systemd-udevd[199] creating link '/dev/disk' to '/dev/vdb' systemd-udevd[199] creating symlink '/dev/disk' to 'vdb' We can see that the symlink /dev/disk was created by system-udevd, and cause boot failed. I also noticed that `blkid /dev/vdb' print nothing, but `blkid /dev/vda*' is normal. The /dev/vdb is correspond to the malloc bdev that spdk created. Is this a bug for system-udevd? (Add centos at centos.org and qemu-discuss at nongun.org in CC list) > -----Original Messages----- > From: wuzhouhui <wuzhouhui14 at mails.ucas.ac.cn> > Sent Time: 2018-10-30 11:31:15 (Tuesday) > To: qemu-discuss at nongnu.org, spdk at lists.01.org > Cc: > Subject: [CASS SPAM][SPDK] VM boot failed sometimes if using vhost-user-blk with spdk > > I'm using following command line to start VM (The /var/tmp/vhost.0 connected to a > malloc bdev (16 MB ) created by SPDK): > /home/wuzhouhui/qemu-2.12.1/x86_64-softmmu/qemu-system-x86_64 \ > -name guest=wzh,debug-threads=on \ > -machine pc-i440fx-2.12,accel=kvm,usb=off \ > -cpu host \ > -m 4096 \ > -object memory-backend-file,id=mem0,size=4096M,mem-path=/dev/hugepages,share=on \ > -numa node,memdev=mem0 \ > -realtime mlock=off \ > -smp 2,sockets=2,cores=1,threads=1 \ > -uuid a84e96e6-2c53-408d-986b-c709bc6a0e51 \ > -no-user-config \ > -nodefaults \ > -rtc base=utc,driftfix=slew \ > -global kvm-pit.lost_tick_policy=delay \ > -no-shutdown \ > -boot strict=on \ > -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \ > -device ahci,id=sata0,bus=pci.0,addr=0x4 \ > -drive file=/home/wuzhouhui/wzh.qcow2,format=qcow2,if=none,id=drive-virtio-disk0,cache=none \ > -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x3,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=0 \ > -device usb-tablet,id=input0,bus=usb.0,port=1 \ > -k en-us \ > -device cirrus-vga,id=video0,bus=pci.0,addr=0x2 \ > -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 -msg timestamp=on \ > -vnc :9 \ > -chardev socket,id=char0,path=/var/tmp/vhost.0 \ > -device vhost-user-blk-pci,id=blk0,chardev=char0,num-queues=4 \ > > But most of the time, VM boot failed with following message in vnc screen: > Warning: /dev/disk/by-uuid/e0dcaf0c-bc23-4df6-b2cd-d40aa1bbb0b5 does not exist > > Generating "/run/initramfs/rdsosreport.txt" > > Entering emergency mode. Exit the shell to continue. > Type "journalctl" to view system logs. > You might want to save "/run/initramfs/rdsosreport.txt" to a USB stick or /boot > after mounting them and attach it to a bug report. > > There is some message from /run/initramfs/rdsosreport.txt: > ... > system-udevd[196]: symlink '../../vdb' '/dev/disk/by-id/virtio-Malloc.tmp-b253:16' failed: Not a directory > ... > > I checked /dev/disk, it should be a directory, but it is a symlink now: > :/# ls -l /dev/disk > lrwxrwxrwx 1 root 0 3 Oct 30 03:08 /dev/disk -> vdb > > If I just remove: > -chardev socket,id=char0,path=/var/tmp/vhost.0 \ > -device vhost-user-blk-pci,id=blk0,chardev=char0,num-queues=4 \ > The VM will boot normally. > > Does anyone have encountered similar issue like this? > > Host OS: CentOS 7.3, with kernel 3.10.0-862.11.6.el7.x86_64 > Guest OS: CentOS 7.5 > Qemu: 2.12.1 > SPDK: f0cb7b871e in master > _______________________________________________ > SPDK mailing list > SPDK at lists.01.org > https://lists.01.org/mailman/listinfo/spdk _______________________________________________ SPDK mailing list SPDK at lists.01.org https://lists.01.org/mailman/listinfo/spdk