Question

CCTV onto SSD instead of HDD

  • 1 December 2020
  • 2 replies
  • 146 views

Hello Nutanix Community

I have a VM that is running CCTV operations. I record multiple video streams in a high resolution and frame rate. Old files get deleted when the space is used up. How can I make sure that the SSDs are not being used for the recording to avoid them to get too many write cycles too fast?

Kind regards,
Ibinema


2 replies

Userlevel 6
Badge +5

There is a way to pin a VM to a hot tier but not the opposite. Nutanix clusters are designed to store at least some of the data on SSDs before flushing it to the cold tier. This is just a part of the data cycle within the storage.

Moreover, as far as know, CCTV requires low latency storage anyway due to the large throughput of data (you mentioned high resolution and multiple video streams).

If the storage latency is too high (read HDD is not fast enough to process all the I/O the system may hang or crush.

Userlevel 4
Badge +5

As the CCTV applications mostly write the data sequentially in large block sizes, it might be beneficial to write to the HDDs. You may try to change the tier priority of the sequential IO on the storage container level:

ncli container edit name=<container_name> sequential-io-priority-order=DAS-SATA,SSD-SATA,SSD-PCIe

Make sure that there is nothing else other than CCTV application using that container, as it will negatively affect the performance of everything else.

It is possible that it will not change a lot, because it depends on how the application that handles the CCTV data works. If it gets worse, just revert to default by running this command:

ncli container edit name=<container_name> sequential-io-priority-order=SSD-PCIe,SSD-SATA,DAS-SATA

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