Thanks Rich, you’re gold.
NTP
I have installed NTP after noticing this.
I have a local ntp server which a GPS clock.
Zigbee
The plugs I have for the fridge Freezer and other devices are default OFF.
I have openHAB rules which monitor their state, with a ‘desired state’ item, which if not matched, will switch to that state.
Light switches
… or not. Yes, I do remember the conversation, and after years of agonising about it, I have decided to install one light switch per room. However, all others run Zigbee.
uptime
I also understand uptime and nines. Used to build install data centres in my life 
The whole property never failed in 10+ years.
Yesterday, I have ordered a battery for a small CyberPower UPS, just for the Pi and its current configuration (as an immediate fix).
Persistence
Yes, rrd4j. I have 640 items persisted. I know I have to revisit and work on what gets persisted. My comment was to mention, ey, this is what can happen. With ntp in place, this issue should be gone.
SD card mirror
Thanks, will check the docs.
If a month out, I might be able to use it to restore rrd4j files.
… if this is possible, as in rrd4j not discarding them.
ZRAM
I have seen a most recent response from Markus Storm on zram sync… but this is not the default setting. → Feeding my suspicion that any backup will not backup whatever is managed by zram.
Mapping warning
I should have been clearer in my description; while this happened, the issue is that OH doe snot tell me which map file is the cause.
Image stream error
I have to search for it. I did create an item with that icon, but the icon does not exist.
openHABian config
Which version?
2024-03-16_21:49:00_AEST [openHABian] openHABian configuration tool version: [openHAB3]{2023-12-12T18:59:04+01:00}(8e591be)
prevent data loss, zram or not
From what I have gathered so far, though have to confirm; ZRAM data is not backed up. Meaning I would have to shutdown OH, which is simply not feasible. I will try mstormi’s suggested sync command via cron. If this works the problem is solved. If not, ZRAM will have to go, which implies running on SSD.
Just saw mstormi’s post #7…
systemctl list-timers
NEXT LEFT LAST PASSED UNIT A>
Sun 2024-03-17 16:11:34 AEST 7h left n/a n/a apt-daily.timer a>
Sun 2024-03-17 21:29:59 AEST 13h left Sat 2024-03-16 21:29:59 AEST 10h ago systemd-tmpfiles-clean.timer s>
Mon 2024-03-18 00:00:00 AEST 15h left Sun 2024-03-17 00:00:01 AEST 8h ago atop-rotate.timer a>
Mon 2024-03-18 00:00:00 AEST 15h left Sun 2024-03-17 00:00:01 AEST 8h ago exim4-base.timer e>
Mon 2024-03-18 00:00:00 AEST 15h left Sun 2024-03-17 00:00:01 AEST 8h ago logrotate.timer l>
Mon 2024-03-18 00:00:00 AEST 15h left Sun 2024-03-17 00:00:01 AEST 8h ago man-db.timer m>
Mon 2024-03-18 00:00:35 AEST 15h left Mon 2024-03-11 00:06:24 AEST 6 days ago fstrim.timer f>
Mon 2024-03-18 00:57:09 AEST 16h left Sun 2024-03-17 00:58:39 AEST 7h ago amdump-openhab-dir.timer a>
Mon 2024-03-18 01:56:38 AEST 17h left Sun 2024-03-17 02:01:17 AEST 6h ago amandaBackupDB.timer a>
Mon 2024-03-18 02:01:44 AEST 17h left Sun 2024-03-17 02:06:02 AEST 6h ago sdrsync.timer s>
Mon 2024-03-18 03:28:55 AEST 19h left Sun 2024-03-17 02:39:19 AEST 5h 44min ago firemotd.timer f>
Mon 2024-03-18 06:07:07 AEST 21h left Sun 2024-03-17 06:44:54 AEST 1h 38min ago apt-daily-upgrade.timer a>
Sun 2024-03-24 03:10:19 AEST 6 days left Sun 2024-03-17 03:10:02 AEST 5h 13min ago e2scrub_all.timer e>
Mon 2024-07-01 01:15:00 AEST 3 months 14 days left Mon 2024-01-01 01:15:01 AEST 2 months 15 days ago sdrawcopy.timer s>
14 timers listed.
Pass --all to see loaded but inactive timers, too.
No… I have only one system, and this needed to get back online as quickly as possible. However, I will create a test system to try. For the time being I have given up on restoring any persistence data.
Well, given the zram uncertainties (that exist for me at least at the moment), the backup seems to be incomplete, based on what is held in zram.
When I take a backup via openhab-cli, OH does not get shut down (for zram data to be written). Unless the backup process a ‘flush zram data to dusk’ there won’t b a complete backup.
Can someone tell me, if zram data is written when backing up via openhab-cli tool?
In any case, I do appreciate the responses.