Question on Datacenter Summary vs Datacenter Ceph Usage Discrepancy

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Oct 18, 2019
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I'm curious why the difference here?

86TB of Summary Storage, but Ceph Usage shows 120TB total. Ceph is much closer to the original full raw amount of data from all the drives. The amount used also in the Summary seems far too high as well.

Screen Shot 2019-11-14 at 11.08.45 PM.png

and

Screen Shot 2019-11-14 at 11.08.29 PM.png
 
Hi,

I'm curious why the difference here?

So first off, the Datacenter Summary one shows the real available storage of all storages defined, you can edit the browser-local settings under "Username->Settings" and select only the ceph one, and the usage should change.

But that's only one difference, the other is that the Ceph overview panel one shows the raw usage, whereas the DC summary one shows the useable. The difference is that raw one is just the sum of all OSDs for available and sum of all objects for the used.
And the "real usable" accounts that ceph saves objects more than one time for redundancy, so if you have a single pool with replica/min-replica 3/2 this would simply be a third of the raw usage, if you have more pools it may get more complex.

But maybe we could really write "Raw Usage" for the Ceph summary chart, as it can be a bit confusing, yes..
 
So first off, the Datacenter Summary one shows the real available storage of all storages defined, you can edit the browser-local settings under "Username->Settings" and select only the ceph one, and the usage should change.

Thanks for helping to clarify this. So why is the Summary so much lower? I still dont understand that very well cause it should be a higher total of ceph in my case, as all disks are available but not all disks are OSDs right?

Also, there is no way I'm using 45TB of data as the summary states. I have 3 pools

SSD-POOL - 3 500GB SSDs 3/2 (2VM @20GB) CEPH
NVME-POOL - 9 1TB SSD 3/2 (5VMs @20GB) CEPH
HDD-POOL - 12 10TB 3/2 (1 Disk Image of 12TB) CEPH
System Disk - 3 x 120GB SSD

So why is 48 used out of 86TB total for Summary Storage?

So maybe 36TB with 3/2, but not 48? It seems odd to me or not very clear what this is. I'll dig around some and see if I can understand it better.
 
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