12:37 p.m.
On 9/22/23 16:47, Lee Garrett wrote:
On 22.09.23 14:54, Richard W.M. Jones wrote:
> On Fri, Sep 22, 2023 at 11:40:03AM +0100, Richard W.M. Jones wrote:
>> On Thu, Sep 21, 2023 at 07:47:52PM +0200, Lee Garrett wrote:
>>> On 21.09.23 19:43, Richard W.M. Jones wrote:
>>>> So this is probably another instance or variation of the timezone
>>>> formatting problem (of schtasks). Which version of virt-v2v is this?
>>>> I want to check that you have a version with all the latest patches in
>>>> this area.
>>>
>>> It's 2.2.0-1 from Debian (12) bookworm. I've verified that it
>>> doesn't have any distro-specific patches.
>>>
>>> (https://salsa.debian.org/libvirt-team/virt-v2v/-/tree/debian/master/debian
>>> would have a patches/series file in this case)
>>
>> The timezone fixes are:
>>
>> commit 597d177567234c3a539098c423649781424eeb6f
>> Author: Laszlo Ersek <lersek(a)redhat.com>
>> Date: Tue Mar 8 15:30:51 2022 +0100
>>
>> convert_windows: rewrite "configure_qemu_ga" script purely in
>> PowerShell
>>
>> commit d9dc6c42ae64ba92993dbd9477f003ba73fcfa2f
>> Author: Richard W.M. Jones <rjones(a)redhat.com>
>> Date: Fri Nov 12 08:47:55 2021 +0000
>>
>> convert/convert_windows.ml: Handle date formats with dots
>> instead of /
>>
>> They are all included in >= 2.0
>>
>> I wonder if 597d177567 has a subtle flaw, or if we introduced a bug
>> somewhere when refactoring this code later.
>>
>> Lee: Do you have a theory about exactly what is wrong with the
>> schtasks date? Like what was it supposed to be, assuming it was 120
>> seconds in the future from boot time, versus what it was set to:
>>
>>> Firstboot-qemu-ga 9/21/2023 4:04:00 PM Ready
>>
>> Could a date or time field have not been swapped or been corrupted
>> in some predictable way?
>
> Or in even simpler terms, what is the time (and timezone) that
> this ^^^ machine was booted?
I believe I have it figured out.
The guest local time is currently 7:08 AM (a few minutes after
firstboot/provisioning), pacific daylight time (UTC-7, though Windows
displays it as "UTC-08:00"). This is the timezone that the guest comes
configured with at first boot. The task is scheduled for 2:01 PM,
meaning it's scheduled to run ~7 hours in the future.
So it seems like the task was meant to be scheduled for 2:01 PM UTC (=
7:01 AM PDT), but for some reason was scheduled for 2:01 PM *local time*.
From what I can see, the host machine time zone is irrelevant (UTC+2).
I don't know where the timezone mixup comes from, though. Running
`(get-date)` in the powershell at this point correctly returns the local
time (7:08 AM). I guess during injection the time is in UTC, and
schtasks.exe has no awareness of timezones?
Right, I think there is a timezone disagreement between how we format the timestamp and
how schtasks.exe takes it.
What matters here is the /ST (start time) flag.
Today we have (in the common submodule):
add "$d = (get-date).AddSeconds(120)";
add "$dtfinfo = [System.Globalization.DateTimeFormatInfo]::CurrentInfo";
add "$sdp = $dtfinfo.ShortDatePattern";
add "$sdp = $sdp -replace 'y+', 'yyyy'";
add "$sdp = $sdp -replace 'M+', 'MM'";
add "$sdp = $sdp -replace 'd+', 'dd'";
add "schtasks.exe /Create /SC ONCE `";
add " /ST $d.ToString('HH:mm') /SD $d.ToString($sdp) `";
add " /RU SYSTEM /TN Firstboot-qemu-ga `";
add (sprintf " /TR \"C:\\%s /forcerestart /qn /l+*vx
C:\\%s.log\""
msi_path msi_path);
Note that for the /ST option's argument, we only perform the following steps:
$d = (get-date).AddSeconds(120)
/ST $d.ToString('HH:mm')
This actually goes back to commit dc66e78fa37d ("windows: delay installation of
qemu-ga MSI", 2020-03-10). The timestamp massaging we've since done only targeted
the /SD (start date) option, not the start time (/ST) one!
So the problem may be that
(get-date).AddSeconds(120).ToString('HH:mm')
formats the hour:minute timestamp in UTC (why though?), but the /ST option takes
hour:minute in local time.
Interestingly, DateTime objects seem to have a "Kind" property, which may be
Utc, Local, or Unspec.
https://learn.microsoft.com/en-us/dotnet/api/system.datetime.kind
It seems to be used when converting from UTC to local or vice versa, and it probably
influences how ToString() behaves too. I thought "get-date" returned a Local
one, and /ST took a local one as well, but perhaps "get-date" returns a UTC
timestamp in this case (when run from the script)?
Laszlo
>
> Rich.
>
>> The code we run is here:
>>
>>
https://github.com/libguestfs/libguestfs-common/blob/e70d89a58dae068be2e1...
>>
>> Ming: this could be a bug affecting PST (UTC-8) guests, perhaps
>> somehow related to having a single digit month field?
>>
>> Rich.
>>
>> --
>> Richard Jones, Virtualization Group, Red Hat
>> http://people.redhat.com/~rjones
>> Read my programming and virtualization blog: http://rwmj.wordpress.com
>> libguestfs lets you edit virtual machines. Supports shell scripting,
>> bindings from many languages. http://libguestfs.org
>