GNS3server timeout when you create a disk with qcow2 preallocation different off

[Mario156090]

Hello dear GNS3 developer team, today I need to create a Qcow2 disk from GNS3 and when I create the disk in qemu VM and I add the VM to a project GNS3 is break. This happen with normal user and root user. This happen when we create a qcow2 disk with prealocate different off. So for fix this We need reinstall GNS3 because the config is break.

[grossmj]

Thanks for the report. I can reproduce the problem.

The problem is the GNS3 server calls qemu-img and a preallocation makes it slow to create the image and then the GUI timeouts.

For instance, it takes around 35s on my system to preallocate a 30 GB image: (default timeout is 30 seconds)

$ time qemu-img create -f qcow2 -o lazy_refcounts=off -o preallocation=full TEST2.qcow2 30000M
Formatting 'TEST2.qcow2', fmt=qcow2 cluster_size=65536 extended_l2=off preallocation=full compression_type=zlib size=31457280000 lazy_refcounts=off refcount_bits=16

real    0m35.224s
user    0m0.041s
sys 0m13.527s

[Mario156090]

Thanks for the report. I can reproduce the problem.

The problem is the GNS3 server calls qemu-img and a preallocation makes it slow to create the image and then the GUI timeouts.

For instance, it takes around 35s on my system to preallocate a 30 GB image: (default timeout is 30 seconds)

$ time qemu-img create -f qcow2 -o lazy_refcounts=off -o preallocation=full TEST2.qcow2 30000M
Formatting 'TEST2.qcow2', fmt=qcow2 cluster_size=65536 extended_l2=off preallocation=full compression_type=zlib size=31457280000 lazy_refcounts=off refcount_bits=16

real  0m35.224s
user  0m0.041s
sys   0m13.527s

Oh, OK, so the option for preallocate should be deprecated? because some person as me can try to do pre allocate 150G hhaahaha.

[grossmj]

Oh, OK, so the option for preallocate should be deprecated? because some person as me can try to do pre allocate 150G hhaahaha.

I will keep the option, I just have to make it non-blocking on the server side and no timeout for the progress bar on the GUI side ;)