Re: qemu-nbd: Failed to bind socket: No such file or directory

[宋文武 <iyzsong@gmail.com>]

Ludovic Courtès <ludo@gnu.org> writes:

> 白い熊＠相撲道 <guix-devel_gnu.org@sumou.com> skribis:
>
>> On 2015-03-26 22:24, ludo@gnu.org wrote:
>>> I have no idea, but I would recommend running:
>>>
>>>   sudo strace -o log qemu-nbd -c /dev/nbd0 disk.qcow2
>>>
>>> and then find out the socket name in ‘log’ above “Failed to bind
>>> socket”.
>>
>> Yeah, was exploring this... I'm attaching the strace log, I don't
>> understand what's causing it... Any ideas?
>
> [...]
>
>> --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=2063, si_status=0, si_utime=0, si_stime=0} ---
>> read(3, "Failed to bind socket: No such f"..., 1024) = 49
>> write(2, "Failed to bind socket: No such f"..., 49) = 49
>
> The problem seems to happen in a child process.  Can you add the ‘-f’
> flag to the ‘strace’ command line so we have details about child
> processes?
I tried 'strace -f', then find out that qemu-nbd need access to "/var/lock".
After "mkdir /var/lock", it works.
>
> TIA,
> Ludo’.