The GUI is showing the raw space available to ScaleIO as in "how much disk space you have given it", in your case 6*900 = ~5.4TB. As your data is essentially duplicated, if you create and use 1.6tb of a thin-provisioned 3TB volume, then the raw space that will take from your pool is approx twice that, so 2x1.6tb = roughly 3.4tb.
Look into the scli --query_volume command for more details on how much space is used, but if you're wondering why it's not just using 1.6TB then see above and know that you don't get a single-instance copy of your data. That never happens in ScaleIO, it's always duplicated. Mirrored, whether you like it or not
I am assuming you are using thin provisioning, is that correct?
Please remember that in ScaleIO every chunk of data is mirrored - so when you create a 100GB volume "Used space" is actually twice as much, due to mirroring:
Thank you very much. I was thinking of it as a RAID5 sort of deal where you lose a drive's worth of capacity to parity in the array. In actuality, though, for ScaleIO, it's (Total - spare)/2. That's a pretty hefty penalty as far as capacity is concerned, but then again, I do like to keep my data safe! Thanks again!
andyinv
37 Posts
0
July 28th, 2017 01:00
The GUI is showing the raw space available to ScaleIO as in "how much disk space you have given it", in your case 6*900 = ~5.4TB. As your data is essentially duplicated, if you create and use 1.6tb of a thin-provisioned 3TB volume, then the raw space that will take from your pool is approx twice that, so 2x1.6tb = roughly 3.4tb.
Look into the scli --query_volume command for more details on how much space is used, but if you're wondering why it's not just using 1.6TB then see above and know that you don't get a single-instance copy of your data. That never happens in ScaleIO, it's always duplicated. Mirrored, whether you like it or not
pawelw1
306 Posts
1
July 28th, 2017 02:00
Hi,
I am assuming you are using thin provisioning, is that correct?
Please remember that in ScaleIO every chunk of data is mirrored - so when you create a 100GB volume "Used space" is actually twice as much, due to mirroring:
scli --add_volume --volume_name test1 --size_gb 104 --storage_pool_name sp1 --protection_domain_name pd1
scli --query_all:
(...)
208.0 GB (212992 MB) in-use capacity
0 Bytes thin capacity
208.0 GB (212992 MB) protected capacity
Hope this helps!
Cheers,
Pawel
clintyjd
2 Posts
0
July 28th, 2017 16:00
Thank you very much. I was thinking of it as a RAID5 sort of deal where you lose a drive's worth of capacity to parity in the array. In actuality, though, for ScaleIO, it's (Total - spare)/2. That's a pretty hefty penalty as far as capacity is concerned, but then again, I do like to keep my data safe! Thanks again!