Hi Tim,
Likely this is a combination of two factors:
- Files changing/temp files being created and deleted/other such filesystem changes
- How Resilient Change Tracking (RCT, Hyper-V's version of Changed Block Tracking (CBT)) works in general
If even a single byte in a block is changed, the entire block is returned by RCT as a changed block and read/transferred. As you observed, Veeam's deduplication/compression will handle this fairly well, but it's expected that a combination of how RCT works and how operating systems work. Remember, the RCT files are metadata about the changed blocks, so that's why the math is likely off.
These values look pretty normal even for "non-busy" servers, as the OS is still making lots of changed data even if the total OS disk usage doesn't increase.
Likely this is a combination of two factors:
- Files changing/temp files being created and deleted/other such filesystem changes
- How Resilient Change Tracking (RCT, Hyper-V's version of Changed Block Tracking (CBT)) works in general
If even a single byte in a block is changed, the entire block is returned by RCT as a changed block and read/transferred. As you observed, Veeam's deduplication/compression will handle this fairly well, but it's expected that a combination of how RCT works and how operating systems work. Remember, the RCT files are metadata about the changed blocks, so that's why the math is likely off.
These values look pretty normal even for "non-busy" servers, as the OS is still making lots of changed data even if the total OS disk usage doesn't increase.
Statistics: Posted by david.domask — Jul 01, 2024 2:56 pm
