[Qemu-devel] [Bug 1502095] [NEW] Sporadic input / output error — x86-64 linux guest

[Davide Baldini]

Public bug reported:

** Setup: **

→ Host
    Qemu version 2.4.0.1
    Linux: 4.1.1 (Debian 8.2, GCC 4.9.2, x86_64)
    filesystem ext3 and ext4
    one single host machine

→ Guests (3 VMs)
    architecture x86_64, Linux 3.16.0-4-amd64 (Debian 7.6)
    virtual disk qcow2, uncompressed
    guests filesystem ext3
    virtual disks size:  VM1: 3GB,  VM2: 5GB,  VM3: 250GB

→ Network
    bridge (br0) and tap interfaces.

** Command line **

For all 3 VMs, the command line is similar to the following. Only RAM
size and ID ("109") are changed.

    /usr/local/bin/qemu-system-x86_64 -hda /media/raid1/qemu-109 -m 8G -smp 4 
-enable-kvm \
        -netdev bridge,id=br109 -device 
virtio-net-pci,netdev=br109,id=nic0,mac=00:00:00:00:01:09 \
        -k it -daemonize

** Problem **

Sporadic, unexplained input output error.
When I try to SSH to one of the instances, most of the times everything just 
works fine. Some other times, the SSH connection can be established, but as I 
interact with the guest via SSH (ls, cd, top) the guest reports "input / output 
error" on the SSH console. Sometimes, the SSH daemon on the guest answers 
"/bin/bash input output error". Sometimes the SSH client answers that the 
connection has been dropped by the host.

When this happens, the web services I run on the VMs are and remain 
unreachable, the VMs themselves are and remain unreachable/unusable via SSH as 
described, and after killing the relative qemu processes and restarting the 
VMs, no recent logs are registered on /var/logs on the guests, arguably since 
the time of the crash.
The crash is not triggered by SSH, I just find SSH to be nonfunctional after I 
spot my web services offline.

This only happens to one VM at a time, independently. The other VMs
appear to run fine when one VM encounters the problem.

I wish instructions to further debug this.

** Affects: qemu
     Importance: Undecided
         Status: New

** Description changed:

  ** Setup: **
  
  → Host
-     Qemu version 2.4.0.1
-     Linux: 4.1.1 (Debian 8.2, GCC 4.9.2, x86_64)
-     filesystem ext3 and ext4
+     Qemu version 2.4.0.1
+     Linux: 4.1.1 (Debian 8.2, GCC 4.9.2, x86_64)
+     filesystem ext3 and ext4
+     one single host machine
  
  → Guests (3 VMs)
-     architecture x86_64, Linux 3.16.0-4-amd64 (Debian 7.6)
-     virtual disk qcow2, uncompressed
-     guests filesystem ext3
-     virtual disks size:  VM1: 3GB,  VM2: 5GB,  VM3: 250GB
+     architecture x86_64, Linux 3.16.0-4-amd64 (Debian 7.6)
+     virtual disk qcow2, uncompressed
+     guests filesystem ext3
+     virtual disks size:  VM1: 3GB,  VM2: 5GB,  VM3: 250GB
  
  → Network
-     bridge (br0) and tap interfaces.
- 
+     bridge (br0) and tap interfaces.
  
  ** Command line **
  
  For all 3 VMs, the command line is similar to the following. Only RAM
  size and ID ("109") are changed.
  
-     /usr/local/bin/qemu-system-x86_64 -hda /media/raid1/qemu-109 -m 8G -smp 4 
-enable-kvm \
-         -netdev bridge,id=br109 -device 
virtio-net-pci,netdev=br109,id=nic0,mac=00:00:00:00:01:09 \
-         -k it -daemonize
- 
+     /usr/local/bin/qemu-system-x86_64 -hda /media/raid1/qemu-109 -m 8G -smp 4 
-enable-kvm \
+         -netdev bridge,id=br109 -device 
virtio-net-pci,netdev=br109,id=nic0,mac=00:00:00:00:01:09 \
+         -k it -daemonize
  
  ** Problem **
  
  Sporadic, unexplained input output error.
- When I try to SSH to one of the instances, most of the times everything just 
works fine. Some other times, the SSH connection can be established, but as I 
interact with the guests via SSH (ls, cd, top) the guest reports "input / 
output error" on the SSH console. Sometimes, the SSH daemon on the guest 
answers "/bin/bash input output error". Sometimes the SSH client answers that 
the connection has been dropped by the host.
+ When I try to SSH to one of the instances, most of the times everything just 
works fine. Some other times, the SSH connection can be established, but as I 
interact with the guest via SSH (ls, cd, top) the guest reports "input / output 
error" on the SSH console. Sometimes, the SSH daemon on the guest answers 
"/bin/bash input output error". Sometimes the SSH client answers that the 
connection has been dropped by the host.
  
  When this happens, the web services I run on the VMs get unreachable,
  the VMs themselves are unreachable/unusable via SSH as described, and
  after killing the relative qemu processes and restarting the VMs, no
- recent logs are registered on /var/logs, arguably since the time of the
- crash.
+ recent logs are registered on /var/logs on the guests, arguably since
+ the time of the crash.
  
  This only happens to one VM at a time, independently. The other VMs
  appear to run fine when one VM encounters the problem.
  
- I which instructions to further debug this.
+ I wish instructions to further debug this.

** Description changed:

  ** Setup: **
  
  → Host
      Qemu version 2.4.0.1
      Linux: 4.1.1 (Debian 8.2, GCC 4.9.2, x86_64)
      filesystem ext3 and ext4
-     one single host machine
+     one single host machine
  
  → Guests (3 VMs)
      architecture x86_64, Linux 3.16.0-4-amd64 (Debian 7.6)
      virtual disk qcow2, uncompressed
      guests filesystem ext3
      virtual disks size:  VM1: 3GB,  VM2: 5GB,  VM3: 250GB
  
  → Network
      bridge (br0) and tap interfaces.
  
  ** Command line **
  
  For all 3 VMs, the command line is similar to the following. Only RAM
  size and ID ("109") are changed.
  
      /usr/local/bin/qemu-system-x86_64 -hda /media/raid1/qemu-109 -m 8G -smp 4 
-enable-kvm \
          -netdev bridge,id=br109 -device 
virtio-net-pci,netdev=br109,id=nic0,mac=00:00:00:00:01:09 \
          -k it -daemonize
  
  ** Problem **
  
  Sporadic, unexplained input output error.
  When I try to SSH to one of the instances, most of the times everything just 
works fine. Some other times, the SSH connection can be established, but as I 
interact with the guest via SSH (ls, cd, top) the guest reports "input / output 
error" on the SSH console. Sometimes, the SSH daemon on the guest answers 
"/bin/bash input output error". Sometimes the SSH client answers that the 
connection has been dropped by the host.
  
- When this happens, the web services I run on the VMs get unreachable,
- the VMs themselves are unreachable/unusable via SSH as described, and
- after killing the relative qemu processes and restarting the VMs, no
- recent logs are registered on /var/logs on the guests, arguably since
- the time of the crash.
+ When this happens, the web services I run on the VMs are and remain
+ unreachable, the VMs themselves are and remain unreachable/unusable via
+ SSH as described, and after killing the relative qemu processes and
+ restarting the VMs, no recent logs are registered on /var/logs on the
+ guests, arguably since the time of the crash.
  
  This only happens to one VM at a time, independently. The other VMs
  appear to run fine when one VM encounters the problem.
  
  I wish instructions to further debug this.

** Description changed:

  ** Setup: **
  
  → Host
      Qemu version 2.4.0.1
      Linux: 4.1.1 (Debian 8.2, GCC 4.9.2, x86_64)
      filesystem ext3 and ext4
      one single host machine
  
  → Guests (3 VMs)
      architecture x86_64, Linux 3.16.0-4-amd64 (Debian 7.6)
      virtual disk qcow2, uncompressed
      guests filesystem ext3
      virtual disks size:  VM1: 3GB,  VM2: 5GB,  VM3: 250GB
  
  → Network
      bridge (br0) and tap interfaces.
  
  ** Command line **
  
  For all 3 VMs, the command line is similar to the following. Only RAM
  size and ID ("109") are changed.
  
      /usr/local/bin/qemu-system-x86_64 -hda /media/raid1/qemu-109 -m 8G -smp 4 
-enable-kvm \
          -netdev bridge,id=br109 -device 
virtio-net-pci,netdev=br109,id=nic0,mac=00:00:00:00:01:09 \
          -k it -daemonize
  
  ** Problem **
  
  Sporadic, unexplained input output error.
  When I try to SSH to one of the instances, most of the times everything just 
works fine. Some other times, the SSH connection can be established, but as I 
interact with the guest via SSH (ls, cd, top) the guest reports "input / output 
error" on the SSH console. Sometimes, the SSH daemon on the guest answers 
"/bin/bash input output error". Sometimes the SSH client answers that the 
connection has been dropped by the host.
  
- When this happens, the web services I run on the VMs are and remain
- unreachable, the VMs themselves are and remain unreachable/unusable via
- SSH as described, and after killing the relative qemu processes and
- restarting the VMs, no recent logs are registered on /var/logs on the
- guests, arguably since the time of the crash.
+ When this happens, the web services I run on the VMs are and remain 
unreachable, the VMs themselves are and remain unreachable/unusable via SSH as 
described, and after killing the relative qemu processes and restarting the 
VMs, no recent logs are registered on /var/logs on the guests, arguably since 
the time of the crash.
+ The crash is not triggered by SSH, I just try to SSH into the guests when I 
spot my web services offline.
  
  This only happens to one VM at a time, independently. The other VMs
  appear to run fine when one VM encounters the problem.
  
  I wish instructions to further debug this.

** Description changed:

  ** Setup: **
  
  → Host
      Qemu version 2.4.0.1
      Linux: 4.1.1 (Debian 8.2, GCC 4.9.2, x86_64)
      filesystem ext3 and ext4
      one single host machine
  
  → Guests (3 VMs)
      architecture x86_64, Linux 3.16.0-4-amd64 (Debian 7.6)
      virtual disk qcow2, uncompressed
      guests filesystem ext3
      virtual disks size:  VM1: 3GB,  VM2: 5GB,  VM3: 250GB
  
  → Network
      bridge (br0) and tap interfaces.
  
  ** Command line **
  
  For all 3 VMs, the command line is similar to the following. Only RAM
  size and ID ("109") are changed.
  
      /usr/local/bin/qemu-system-x86_64 -hda /media/raid1/qemu-109 -m 8G -smp 4 
-enable-kvm \
          -netdev bridge,id=br109 -device 
virtio-net-pci,netdev=br109,id=nic0,mac=00:00:00:00:01:09 \
          -k it -daemonize
  
  ** Problem **
  
  Sporadic, unexplained input output error.
  When I try to SSH to one of the instances, most of the times everything just 
works fine. Some other times, the SSH connection can be established, but as I 
interact with the guest via SSH (ls, cd, top) the guest reports "input / output 
error" on the SSH console. Sometimes, the SSH daemon on the guest answers 
"/bin/bash input output error". Sometimes the SSH client answers that the 
connection has been dropped by the host.
  
  When this happens, the web services I run on the VMs are and remain 
unreachable, the VMs themselves are and remain unreachable/unusable via SSH as 
described, and after killing the relative qemu processes and restarting the 
VMs, no recent logs are registered on /var/logs on the guests, arguably since 
the time of the crash.
- The crash is not triggered by SSH, I just try to SSH into the guests when I 
spot my web services offline.
+ The crash is not triggered by SSH, I just find SSH to be nonfunctional after 
I spot my web services offline.
  
  This only happens to one VM at a time, independently. The other VMs
  appear to run fine when one VM encounters the problem.
  
  I wish instructions to further debug this.

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https://bugs.launchpad.net/bugs/1502095

Title:
  Sporadic input / output error — x86-64 linux guest

Status in QEMU:
  New

Bug description:
  ** Setup: **

  → Host
      Qemu version 2.4.0.1
      Linux: 4.1.1 (Debian 8.2, GCC 4.9.2, x86_64)
      filesystem ext3 and ext4
      one single host machine

  → Guests (3 VMs)
      architecture x86_64, Linux 3.16.0-4-amd64 (Debian 7.6)
      virtual disk qcow2, uncompressed
      guests filesystem ext3
      virtual disks size:  VM1: 3GB,  VM2: 5GB,  VM3: 250GB

  → Network
      bridge (br0) and tap interfaces.

  ** Command line **

  For all 3 VMs, the command line is similar to the following. Only RAM
  size and ID ("109") are changed.

      /usr/local/bin/qemu-system-x86_64 -hda /media/raid1/qemu-109 -m 8G -smp 4 
-enable-kvm \
          -netdev bridge,id=br109 -device 
virtio-net-pci,netdev=br109,id=nic0,mac=00:00:00:00:01:09 \
          -k it -daemonize

  ** Problem **

  Sporadic, unexplained input output error.
  When I try to SSH to one of the instances, most of the times everything just 
works fine. Some other times, the SSH connection can be established, but as I 
interact with the guest via SSH (ls, cd, top) the guest reports "input / output 
error" on the SSH console. Sometimes, the SSH daemon on the guest answers 
"/bin/bash input output error". Sometimes the SSH client answers that the 
connection has been dropped by the host.

  When this happens, the web services I run on the VMs are and remain 
unreachable, the VMs themselves are and remain unreachable/unusable via SSH as 
described, and after killing the relative qemu processes and restarting the 
VMs, no recent logs are registered on /var/logs on the guests, arguably since 
the time of the crash.
  The crash is not triggered by SSH, I just find SSH to be nonfunctional after 
I spot my web services offline.

  This only happens to one VM at a time, independently. The other VMs
  appear to run fine when one VM encounters the problem.

  I wish instructions to further debug this.

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