Forwarded to centos mailing list
-----Original Messages-----
From: wuzhouhui <wuzhouhui14@xxxxxxxxxxxxxxxx>
Sent Time: 2018-10-30 14:06:00 (Tuesday)
To: "storage performance development kit" <spdk@xxxxxxxxxxxx>
Cc: centos@xxxxxxxxxx, qemu-discuss@xxxxxxxxxx
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@xxxxxxxxxx and qemu-discuss@xxxxxxxxxx in CC list)
> -----Original Messages-----
> From: wuzhouhui <wuzhouhui14@xxxxxxxxxxxxxxxx>
> Sent Time: 2018-10-30 11:31:15 (Tuesday)
> To: qemu-discuss@xxxxxxxxxx, spdk@xxxxxxxxxxxx
> 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@xxxxxxxxxxxx
> https://lists.01.org/mailman/listinfo/spdk
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