Re: Odd uuid-ossp behavior on smew and shearwater

On 05/29/2014 02:38 PM, Tom Lane wrote:
> Josh Kupershmidt <schmiddy@gmail.com> writes:
>> On Wed, May 28, 2014 at 11:23 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> I've just committed regression test adjustments to prevent that from
>>> being a failure case, but I am confused about why it's happening.
>>> I wouldn't be surprised at not getting a MAC address on a machine that
>>> lacks any internet connection, but that surely can't describe the
>>> buildfarm environment.  Are you curious enough to poke into it and
>>> see what's going on?  It might be useful to strace a backend that's
>>> trying to execute uuid_generate_v1() and see what the kernel interaction
>>> looks like exactly.
>> Here's the result of attaching strace to an idle backend, then running
>> SELECT uuid_generate_v1(). AFAIR shearwater is a cheaply-hosted OpenVZ
>> VPS under the hood.
> Interesting.  Looks like you have access only to virtual network
> interfaces, and they report all-zero MAC addresses, which the UUID library
> is smart enough to ignore.  If smew is also in a virtual environment
> then that's probably the explanation.  (There are some other buildfarm
> critters that are reporting MAC addresses with the local-admin bit set,
> which I suspect also means they've got virtual network interfaces, but
> with a different treatment of the what-to-report problem.)
>
>             



Almost all my critters run in VMs (all but jacana and bowerbird).

cheers

andrew