I have set ScanMaximumConcurrent to "4" for my setup. Is there any drawbacks to this setting? Too high, too low?
My server has an LSI 9211-8i HBA connected to an LSI Expander hot-swap SAS2 blackplane (the Supermicro SC846 chassis for those wondering).
The Expander utilizes all 4x 6 Gbps channels to have a total of 24 Gbps, or about 3,000 MB/s (megaBytes per seconds). Since each HGST 4GB HDD I have can only substain about 130 MB/s, I was thinking "4 concurrent" at ~520 MB/s isn't an issue since that's only ~17% of the overall bus. Or, the same speed as my Sata 6 SSD I have in the pool on the same controller.
The only drawback I can see is bandwidth. But please correct me if I am wrong.
I'm down to about 14 HDDs in this chassis in the pool. So, having only 1 scan at a time on the SAS2 bus was taking days to get through.
I'd like to bump it to 8x if there isn't any issue?
But, not all drives gets the same bandwidth. For example, here are the four running right now:
108 MB/s
83 MB/s
71 MB/s
133 MB/s
Should I not be running this many concurrent? Can I go higher?
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eduncan911
I have set ScanMaximumConcurrent to "4" for my setup. Is there any drawbacks to this setting? Too high, too low?
My server has an LSI 9211-8i HBA connected to an LSI Expander hot-swap SAS2 blackplane (the Supermicro SC846 chassis for those wondering).
The Expander utilizes all 4x 6 Gbps channels to have a total of 24 Gbps, or about 3,000 MB/s (megaBytes per seconds). Since each HGST 4GB HDD I have can only substain about 130 MB/s, I was thinking "4 concurrent" at ~520 MB/s isn't an issue since that's only ~17% of the overall bus. Or, the same speed as my Sata 6 SSD I have in the pool on the same controller.
The only drawback I can see is bandwidth. But please correct me if I am wrong.
I'm down to about 14 HDDs in this chassis in the pool. So, having only 1 scan at a time on the SAS2 bus was taking days to get through.
I'd like to bump it to 8x if there isn't any issue?
But, not all drives gets the same bandwidth. For example, here are the four running right now:
108 MB/s
83 MB/s
71 MB/s
133 MB/s
Should I not be running this many concurrent? Can I go higher?
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