Difference between File System Capacity and Disk Capacity in Capacity Planner Reports

[Skeme]

Hi,

I'm due to go on my Capacity Planner tool training soon, but I have a question up front that's frustrating me. In the assessment report that comes out of the tool after the analysis, there's a disk utilization section, which lists all the servers under analysis. One column on this report is headed File System Capacity, another Disk Capacity. In every case, the former is less than the latter. What is the exact meaning of these labels?

Some of the numbers are significantly different between the columns, e.g. 20Gb for File System Capacity and 36Gb for Disk Capacity for one server. Is it saying that only 20Gb out of the 36Gb disk is formatted/partitioned for use?

[wathap]

File system is more like logical aspect of the storage, like C:\, D:\, etc.

Disk Capacity is the actualy harddrive or raid capacity. (real physical aspect)

If the number is significantly off, we will have to look why the OS report less file system storage than the physical. And usually the formatted value is less than the raw value. But it should not be 20GB per 36Gb.

[wathap]

to clarify more.

a Seagate drive could be 36GB, and in there could be drive C:\ of 20GB and drive D:\ of 16GB.

[Skeme]

Thanks for the reply. I'm a little confused by the last comment - if there was a C: drive of 20Gb and a 😧 drive of 16Gb, would the file system capacity not show as 36Gb?

I am not at the site where this report was run but will have a closer look at the server that's giving this odd result and will find out exactly what logical drives are partitioned. I'll then report back here with the results and will award points.

[awliste · Accepted solution]

As previously stated:

Disk capacity is 36 GB - physically, there is 36 GB of storage available.

File system is logical capacity - the amount of space consumed by files on those disks.

File system and Disk capacity will never match due to file table overheads.

Hope this helps.

- abe

Integritas!

Abe Lister

Just some guy that loves to virtualize

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Ain't gonna lie. I like points. If what I'm saying is something useful to you, consider sliding me some points for it!

[Skeme]

Thanks guys, that makes perfect sense now - points awarded to you both.