Lxd take long time when i first launch a vm

as you can see, i use this command to launch a vm,but is will takes me about 20min to get it.

➜ /home lxc launch panperson panqa5 --vm
Creating panqa5
Retrieving image: Unpack: 100% (108.26MB/s)

and i use ps command,it shows qeme-img is running

➜ /root ps -ef|grep qemu-img
root 21357 32349 9 04:35 ? 00:01:12 qemu-img dd -f qcow2 -O raw bs=8192 if=/var/snap/lxd/common/lxd/images/lxd_image_unpack_765881720/rootfs.img of=/dev/local/images_ba5cd6e45dca8e2aff985c34149aafddbe3e7b4d4ca67fd4d512156571d553cd.block

and i use the strace command find

strace: Process 21357 attached
ppoll([{fd=8, events=POLLIN|POLLERR|POLLHUP}], 1, NULL, NULL, 8

at the same time, the lxd is real slow to response

the load average is 131.86 on this 96cores arch64 machine

the iotop command return with
TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND
28048 be/4 root 0.00 B/s 0.00 B/s 0.00 % 99.99 % qemu-img dd -f~571d553cd.bloc

i search many related problem about it, such as

https://patchwork.kernel.org/patch/11476383/

but i find those problem pr haved already merged

my lxd version is 4.16 ans it installed by snap,so the qemu is 5.2.0

can someone help me solve this problem?thanks

I guess in your case it’s not stuck so long as just taking a very long time.
On my arm64 systems, it usually takes more like 2-3 minutes for most images, the bulk of the slowness is simply caused by random I/O being very slow on the underlying storage.