Cisco Cisco UCS C250 M1 Extended-Memory Rack-Mount Server 白皮書
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The sequential read and write workloads stay sequential when only one virtual machine is present in the mirror. However,
their I/O changes to random at the disk level when more virtual machines are present, although sequential I/O occurs at the
individual virtual machine level. Hence, the recommended approach is to use time scheduling among the virtual machine
workloads when heavy sequential I/O is expected.
their I/O changes to random at the disk level when more virtual machines are present, although sequential I/O occurs at the
individual virtual machine level. Hence, the recommended approach is to use time scheduling among the virtual machine
workloads when heavy sequential I/O is expected.
With 256-KB 100 percent sequential read I/O on 10, 20, and 30 virtual machines, the system is capable of delivering
bandwidth of up to about 3100 MBps within a response time of 2.5 milliseconds. The bandwidth increases linearly as the
number of virtual machines running I/O is increased (Figure 62).
bandwidth of up to about 3100 MBps within a response time of 2.5 milliseconds. The bandwidth increases linearly as the
number of virtual machines running I/O is increased (Figure 62).
Figure 62. 256-KB Sequential I/O: 100 Percent Read and Queue Depth 1
With 256-KB 100 percent sequential write I/O on 1 and 10 virtual machines, the system is capable of delivering bandwidth
of up to about 816 MBps within a response time of 3.5 milliseconds (Figure 63). This test was run only on 1 and 10 virtual
machines because it uses the available RAID cache to the maximum.
of up to about 816 MBps within a response time of 3.5 milliseconds (Figure 63). This test was run only on 1 and 10 virtual
machines because it uses the available RAID cache to the maximum.
Figure 63. 256-KB Sequential I/O: 100 Percent Write and Queue Depth 1