To dd the iso Solus iso on a USB.
* most likely is 0.

thanks for all your help.
I have another problem,why my system running so slow?just now I right click and no response,terminal window shows up about 1 minute later.system became unuseable,I have to press power button to power off.I never came across this before

That is not normal, you can look with top, also it might be powerd.

I play steam games just now,but keyboard not working,I cannot move in game.I press power button power off.I cannot go into system after reboot.So I go into bsd,but it's too stuck.I type reboot in terminal,but it didn't reboot,I have to press power button to poweroff.I cannot goes into neither system now.

My hardware broken?

Why bsd can boot again?solus still cannot boot

I want to go back to 20.08 version,where can I download the iso file?

20.08 is not supported anymore and the package repository will be removed soon.

unicorn wrote: ↑Sun Aug 01, 2021 6:44 am Why bsd can boot again?solus still cannot boot

Hard to say I am not familiar with Solus. As for GhostBSD did you get it to boot to the GUI login?

I can boot to the GUI login,but very slow,and the system very stuck.I think there is something wrong with my hard disk.My ubuntu also went into problem a few days ago.My hard disk has a bad sector,msybe this cause the problem?I'll check my hard disk.