SNAP Virtio-fs Release Notes

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Description: Currently, the only supported protocol is NFS-over-TCP. NFS-over-RDMA is not supported.

Workaround: N/A

Keywords: NFS-over-TCP; NFS-over-RDMA

Discovered in version: 1.0.0-doca2.8.0

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Description: Due to the lack of recovery support, it is not possible to perform any negative/resilience operations during IO traffic (e.g., destroy and restore).

Workaround: N/A

Keywords: Recovery; negative/resilience operations

Discovered in version: 1.0.0-doca2.8.0

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Description: The following FUSE commands are unsupported: BMAP, SETUPMAPPING, REMOVEMAPPING.

Workaround: N/A

Keywords: FUSE

Discovered in version: 1.0.0-doca2.8.0

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Description: Application restart is not allowed if the application controller has processed FUSE commands.

Workaround: Unload the virtio-fs driver on the host, then restart the application.

Keywords: FUSE

Discovered in version: 1.0.0-doca2.8.0

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Description: The total number of virtio queues the application can create is limited to 2,000.

Workaround: N/A.

Keywords: Virtio queues

Discovered in version: 1.0.0-doca2.8.0

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Description: The following operations are not supported when using Linux's virtio-fs inbox/upstream kernel driver: FLR and the virtio-fs notification queue.

Workaround: N/A

Keywords: FLR; virtio-fs; inbox/upstream kernel driver

Discovered in version: 1.0.0-doca2.8.0

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Description: If the FLR is initiated from the host by writing 1 to the reset file under /sys/bus/pci/devices/bdf/ using the command echo 1 > /sys/bus/pci/devices/0000\:29\:00.2/reset, then the host driver does not create virtqueues, causing the mount point to remain stuck indefinitely.

Workaround: FLR should only be performed without any mount over virtio-fs on the host. To run IO after FLR, reload the virtio-fs host driver.

Keywords: Driver; FLR

Discovered in version: 1.0.0-doca2.8.0

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Description: On the host, when the virtio-fs mount is idle (i.e., no I/O operations), dmesg logs are filled with repeated AppArmor DENIED messages. These messages indicate that the ntpd service is being denied access to specific files by AppArmor. The ntpd service is trying to access /snap/bin/ and /etc/ssl/openssl.cnf, but the AppArmor profile for ntpd does not permit these accesses, resulting in denied requests.

Workaround: Modify the AppArmor profile for ntpd to grant the required read permissions.

1. Locate the AppArmor profile for ntpd. It is typically located in /etc/apparmor.d/ and named usr.sbin.ntpd.

2. Edit the profile and add the required permissions by using a text editor. For example:

   1. Run:

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      sudo nano /etc/apparmor.d/usr.sbin.ntpd
              

   2. Add the following lines to allow ntpd to read the necessary files:

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      /snap/bin/ r,
      /etc/ssl/openssl.cnf r`
              

3. Apply the changes by reloading the AppArmor profile:

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   sudo apparmor_parser -r /etc/apparmor.d/usr.sbin.ntpd
           

Keywords: AppArmor, ntpd

Discovered in version: 1.0.0-doca2.8.0

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Description: With a kernel version older than 6.10, if stress loading and unloading of the virtio_pci and virtiofs drivers is done in a loop, or mount and umount in a loop, then unmounting or unloading the driver may hang.

Workaround: Add a delay of 1 second between loading and unloading of the drivers.

Keywords: virtio_pci; virtiofs

Discovered in version: 1.0.0-doca2.8.0