JoaoJandre commented on PR #11177: URL: https://github.com/apache/cloudstack/pull/11177#issuecomment-3069782796
> took me a while of looking at this to have the penny drop. Code looks good @JoaoJandre , but what is the use case for this? I’d say one would want thin to be thin and fat to be fat. It seems now thin still makes a full clone given this setting and effectively becomes fat. @DaanHoogland `THIN`, `FAT` and `SPARSE` are translated to preallocation methods in qemu-img. `THIN` being `OFF`, `SPARSE` being `METADATA` and `FAT` being `FULL`. When using `preallocation=full`, qemu-img will write the full disk size to storage (filling it with zeros). When using `preallocation=off`, only the actual necessary data is written. So, if you convert an image with virtual size as 50 GB, but real size 5 GB, using FULL, you'll get an image with 50 GB of real size. Using OFF, you'll end up with an image of 5GB of real size. This is the use case of THIN and full-clone. You copy the template but do not preallocate the full disk size. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@cloudstack.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
