Hi,
independent of the size of the combined block device, I am unable to use more than 1018 devices with the "-m" option in nbd-server. So for example:
for i in {0..1999}; do truncate -s 1M mm.$i; done
sudo nbd-server -C /dev/null localhost@33333 -m /home/user/nbd/mm
sudo nbd-client localhost 33333 /dev/nbd0
Then it says:
Negotiation: ..size = 1018MB
bs=1024, sz=1067450368 bytes
which can also be confirmed by mounting /dev/nbd0.
Another example with 5000 files of 500K gives:
Negotiation: ..size = 497MB
bs=1024, sz=521216000 bytes
which gives the same 521216000/1024/500 = 1018 used files.
The same happens when using different sizes or combinations of
sizes and file-counts. I am using nbd 3.20 on x64 Ubuntu 18.04.
Using a configuration file makes no difference. Different hardware
with the same OS and nbd version neither.
Can someone give me some pointers?
Vladimir