My current opinion is that the problem lies with Cloudstack itself, not Ceph. I opened this thread here to rule out the rather unlikely possibility that the issue is related to Ceph storage. Thanks for the links. The Cloudstack thread is actually mine, which I opened there in parallel. I will continue the discussion there.. Am 25.08.2025 um 09:02 schrieb Janne Johansson:
Den mån 25 aug. 2025 kl 08:18 skrev Mevludin Blazevic <mejdibl@yahoo.com>:
Indeed, Ceph FS and RBD serves Cloudstack which in turn uses Ceph FS via NFS for "Secondary Storage". Cloudstack provides a download URL where I can download a raw file via browser or wget. What is odd to me is that the download rate shrinks rapidly around 100GB and it maintains for a few minutes around 140 kbit/s before the connection is completely lost. It is also visible in Ceph when the FS pool read ops per seconds drops to zero.
After I tried other approaches in Cloudstack, I see that other types of large downloads do not show this behaviour, so I do not think that Ceph is doing any throttling.. Interesting to note that the number 100GB comes up in cloudstack docs:
https://docs.cloudstack.apache.org/en/latest/adminguide/templates.html#best-...
This bug report seem to say others have size-related problems aswell, and log lines you could look for:
https://github.com/apache/cloudstack/issues/2820
Looks close to your issue too:
https://lists.apache.org/thread/9g5nf3oj5szydojswmzjyv6r786lht9w