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Flavors

OpenStack flavor entity defines compute virtual server parameters such as:

  • virtual server specifications
    • vCPU count
    • memory amount
    • storage size (both distributed, ephemeral)
    • defines QoS (IOPs, network bandwith, ...)
  • grants access to additional resources (hardware cards for instance GPU)
  • defines set of compute hypervisors where can be virtual server scheduled

What is the right flavor for mine project?

Purpose of following image is to help you choosing best flavor for your project.

Flavor types and naming schema

Flavor type Flavor characteristic HA support (live) migration support GPU support local ephemeral disk resources vCPU efficiency, CPU overcommit old G1 flavor naming
e1.* economic computing, small jobs, limited performance Yes Yes No No ~ PASSMARK 250, 1:8 standard.*
g2.* general purpose, regular jobs / tasks, medium performance Yes Yes No No ~ PASSMARK 750, 1:2 -
c2.* compute HPC, medium performance No Yes No No ~ PASSMARK 750, 1:2 -
c3.* compute HPC, high performance on shared storage No Yes No No ~ PASSMARK 2000, 1:1 hpc.*
p3.* compute HPC, top performance on ephemeral storage No Yes, not guaranteed (1) No Yes ~ PASSMARK 2000, 1:1 hpc.*ephem
a3.* compute HPC, top performance on ephemeral storage No No Yes Yes ~ PASSMARK 2000, 1:1 hpc.*gpu

Notes:

  • (1) Both cold and live virtual server migrations are generally supported even for VMs with ephemeral storage, but they are not guaranteed as there may not be available ephemeral resources where to migrate.

Most frequently used flavors

Flavor name Is public vCPU [-] RAM [GB] HPC SSD GPU Disc throughput [MB/s] IOPS [op/s] Average throughput [MB/s]
e1.tiny Yes 2 2048 No No No 105 400 128
e1.small Yes 2 4096 No No No 105 400 128
e1.medium Yes 4 4096 No No No 105 400 128
e1.large Yes 4 8192 No No No 105 400 128
e1.1xlarge Yes 8 8192 No No No 105 400 128
e1.2xlarge Yes 8 16384 No No No 105 400 128
g2.tiny Yes 2 8192 No No No 1049 1000 256
g2.small Yes 4 8192 No No No 1049 1000 256
g2.medium Yes 4 16384 No No No 1049 1000 256
g2.large No 8 16384 No No No 1049 1000 256
g2.1xlarge No 8 24576 No No No 1049 1000 256
g2.2xlarge No 16 32768 No No No 1049 1000 256
g2.3xlarge No 16 65536 No No No 1049 1000 256
c2.2core-8ram No 2 8192 Yes No No 2097 1000 2560
c2.2core-16ram No 2 16384 Yes No No 2097 1000 2560
c2.2core-30ram No 2 30720 Yes No No 2097 1000 2560
c2.4core-8ram No 4 8192 Yes No No 2097 1000 2560
c2.4core-16ram No 4 16384 Yes No No 2097 1000 2560
c2.4core-30ram No 4 30720 Yes No No 2097 1000 2560
c2.8core-16ram No 8 16384 Yes No No 2097 1000 2560
c2.8core-30ram No 8 30720 Yes No No 2097 1000 2560
c2.16core-30ram No 16 30720 Yes No No 2097 1000 2560
c2.16core-60ram No 16 61440 Yes No No 2097 1000 2560
c2.24core-30ram No 24 30720 Yes No No 2097 1000 2560
c2.24core-60ram No 24 61440 Yes No No 2097 1000 2560
c2.32core-30ram No 32 30720 Yes No No 2097 1000 2560
c2.32core-60ram No 32 61440 Yes No No 2097 1000 2560
c2.32core-120ram No 32 122880 Yes No No 2097 1000 2560
c3.2core-8ram No 2 8192 Yes No No 2097 2000 10240
c3.2core-16ram No 2 16384 Yes No No 2097 2000 10240
c3.2core-30ram No 2 30720 Yes No No 2097 2000 10240
c3.4core-8ram No 4 8192 Yes No No 2097 2000 10240
c3.4core-16ram No 4 16384 Yes No No 2097 2000 10240
c3.4core-30ram No 4 30720 Yes No No 2097 2000 10240
c3.8core-16ram No 8 16384 Yes No No 2097 2000 10240
c3.8core-30ram No 8 30720 Yes No No 2097 2000 10240
c3.8core-60ram No 8 61440 Yes No No 2097 2000 10240
c3.16core-30ram No 16 30720 Yes No No 2097 2000 10240
c3.16core-60ram No 16 61440 Yes No No 2097 2000 10240
c3.24core-30ram No 24 30720 Yes No No 2097 2000 10240
c3.24core-60ram No 24 61440 Yes No No 2097 2000 10240
c3.32core-30ram No 32 30720 Yes No No 2097 2000 10240
c3.32core-60ram No 32 61440 Yes No No 2097 2000 10240
c3.32core-120ram No 32 122880 Yes No No 2097 2000 10240
c3.64core-60ram No 64 61440 Yes No No 2097 2000 10240
c3.64core-120ram No 64 122880 Yes No No 2097 2000 10240
c3.64core-240ram No 64 245760 Yes No No 2097 2000 10240
c3.128core-120ram No 128 122880 Yes No No 2097 2000 10240
c3.128core-240ram No 128 245760 Yes No No 2097 2000 10240

Last update: January 10, 2025