Re: [PATCH manager] report: list recent reboot events and their kernel version

[Maximiliano Sandoval <m.sandoval@proxmox.com>]

Thomas Lamprecht <t.lamprecht@proxmox.com> writes:

> Am 20.07.26 um 14:38 schrieb Alexander Zeidler:
>> Based on the most recent reboot events, it is possible to determine
>> whether and when a crash, fencing, or reboot occurred and with which
>> kernel version the node booted.
>> 
>> Use `wtmpdb last` as a replacement for the well-known `last`, since
>> the latter became obsolete [0] with Debian Trixie / PVE 9.
>> 
>>  # wtmpdb last reboot --fulltimes --limit 5
>>  reboot   system boot  7.0.14-5-pve     Mon Jul 20 14:22:34 2026 - still running
>>  reboot   system boot  7.0.14-5-pve     Thu Jul 16 15:12:16 2026 - crash
>>  reboot   system boot  7.0.14-5-pve     Thu Jul 16 11:20:15 2026 - Thu Jul 16 15:10:46 2026  (03:50)
>>  reboot   system boot  7.0.14-5-pve     Wed Jul 15 13:39:34 2026 - crash
>>  reboot   system boot  7.0.14-2-pve     Wed Jul 15 07:39:18 2026 - Wed Jul 15 13:38:04 2026  (05:58)
>> 
>>  wtmpdb begins Wed Jul 15 07:39:18 2026
>> 
>> [0] https://www.debian.org/releases/trixie/release-notes/issues.html#the-last-lastb-and-lastlog-commands-have-been-replaced
>> 
>> Signed-off-by: Alexander Zeidler <a.zeidler@proxmox.com>
>> ---
>>  PVE/Report.pm | 1 +
>>  1 file changed, 1 insertion(+)
>> 
>> diff --git a/PVE/Report.pm b/PVE/Report.pm
>> index 29433d4a..6049c0bf 100644
>> --- a/PVE/Report.pm
>> +++ b/PVE/Report.pm
>> @@ -36,6 +36,7 @@ my $init_report_cmds = sub {
>>                  'hostname',
>>                  'date -R',
>>                  'cat /proc/cmdline',
>> +                'wtmpdb last reboot --fulltimes --limit 5',
>
> we nowhere depend on wtmpdb so it's not a given that it's installed.

OK, that is not ideal. Afaik only libpam-wtmpdb "Recommends" wtmpdb
(according to debtree).

> For just the boots we could use "journalctl --list-boots -n 5 -r".
> Depending on wtmpdb and writing yet another log file just for kernel version might
> be a bit overkill, given that the info is there in the journal, albeit it *is*
> annoying that we would have to manually parse them from the journal...

For the purposes of support we are more interested about the kernel
version used each boot. It would be interesting to have info about the
BOOT IDs or having the timestamp of the last entry for a give boot
though.

Another consideration of journalctl is that the boots might be rotated
away.

>>                  'pveversion --verbose',
>>                  'cat /etc/hosts',
>>                  'pvesubscription get',

-- 
Maximiliano