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We are accepting applications to use the new Nimbus, and all new and existing users should apply at the application portal. These will be processed and access will be granted from .

Please see the Dates and Links section of the Get Started with the New Nimbus page for further details.

With the new Nimbus hardware online, users are required to convert their existing instances to the new flavours to work on the new compute nodes. This conversion will only work for instances running newer operating systems. Older instances will need to be deleted and rebuilt from scratch. You can read instructions to help with recreating your instance.

Other elements within your Nimbus project (private networks, storage volumes, etc) do not need to be converted.

Any snapshots of an instance root volume taken prior to conversion will also no longer be usable.

Determine Operating System (OS) Version

  1. Determine what distribution and version of Linux your instance is running. Look for a file called /etc/os-release:

    ubuntu@ubuntu-18:~$ cat /etc/os-release
    VERSION="18.04.3 LTS (Bionic Beaver)"
    PRETTY_NAME="Ubuntu 18.04.3 LTS"
  2. Look for the fields NAME and VERSION_ID.

    If they correspond to any of the following values, then your instance can be migrated. 

    NAMEVERSION_IDOperating SystemSupport
    Ubuntu18.04Ubuntu 18.04Can be migrated with full CPU support
    Ubuntu16.04Ubuntu 16.04Can be migrated with limited CPU support
    CentOS Linux7CentOS 7Can be migrated with full CPU support

    If the values do not match anything in the table above, you cannot migrate your instance directly to the new Nimbus hardware. Follow the instructions to recreate your instance and preserve any data volume you have attached.

Update Linux Kernel


  1. If you are running Ubuntu 18.04 or Ubuntu 16.04, update all available packages using apt-get (including the kernel), then restart the instance:

    sudo apt-get update
    sudo apt-get -y dist-upgrade
    sudo reboot
  2. If prompted while performing the upgrade, select keep the local version currently installed (you may be asked multiple times).
  3. After the instance has restarted, upgrade the kernel to the HWE (Hardware Enablement) kernel:

    sudo apt-get -y install linux-generic-hwe-$(lsb_release -rs)

    Again, if prompted while performing the install, select keep the local version currently installed (you may be asked multiple times).

  4.  Once the HWE kernel is installed, shut the instance down:

    sudo shutdown -h now


  1. If you are running CentOS 7, update all packages, in particular the kernel.
  2. Shut the instance down.

    sudo yum makecache
    sudo yum update -y
    sudo shutdown -h now

Resize Instance

Once the instance is shut down, log in to the Nimbus dashboard, then

  1. Go to ComputeInstances. 
  2. Confirm the instance is shut down.
  3. From the drop-down menu on the right of the instance, select Resize Instance:
  4. On the dialog window, resize the instance. The Old Flavor field will be set to the current flavour of your instance; you need to set the New Flavor field the new flavour that corresponds to your old flavor. 

    Old FlavorNew Flavor
  5. After setting the new flavour, click Resize. Your instance goes through a resizing process and when finished the Status will be Confirm or Revert Resize/Migrate.
  6. Click Confirm Resize/Migrate to the right of the instance, to confirm the resize:

Confirm CPU Visibility

Once completed, your instance will be ready to be started back up.

  1. Use SSH to connect to your instance. 
  2. Confirm that your instance can see the new CPUs by running lscpu :
[centos@centos-7 ~]$ lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                1
On-line CPU(s) list:   0
Thread(s) per core:    1
Core(s) per socket:    1
Socket(s):             1
NUMA node(s):          1
Vendor ID:             AuthenticAMD
CPU family:            23
Model:                 1
Model name:            AMD EPYC Processor (with IBPB)
Stepping:              2
CPU MHz:               2345.592
BogoMIPS:              4691.18
Virtualization:        AMD-V
Hypervisor vendor:     KVM
Virtualization type:   full
L0 cache:              0K
L0 cache:              677K
NUMA node0 CPU(s):     0
Flags:                 fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm art rep_good nopl xtopology extd_apicid amd_dcm eagerfpu pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm cmp_legacy svm cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw topoext perfctr_core retpoline_amd ssbd ibpb vmmcall fsgsbase tsc_adjust bmi1 avx2 smep bmi2 rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 arat

IMPORTANT: For Ubuntu 16 instances, the above command does not work. As mentioned previously, this means the instance does not support the new Epyc features. It will still run on the new compute nodes, however.

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