WAL file cannot be resolved, backup might be incomplete.

[staze]

Seeing this error last couple days with nightly backups on my MB Nano SD.

Full log entires for midnight are:

export (15.08.2020 00:00:01): 15 lines of data written to file: NOAA-monthly-imp-202008-day.txt
backup (15.08.2020 00:00:03): backup media size is 1.7G (1.6G free).
backup (15.08.2020 00:00:19): WAL file cannot be resolved, backup might be incomplete.
backup (15.08.2020 00:05:15): backup completed: dbase-202008150000.gz (16.5M)

Giving things a reboot to grab latest firmware, but curious if anyone has any thoughts on what this means.

[staze]

Still seeing this. Grabbing latest firmware to check if it's been resolved.

@admin, any thought what this is?

[staze]

Just grabbed current firmware. Issue seems to be resolved.

backup (05.09.2020 13:55:09): backup media size is 1.7G (1.6G free).
backup (05.09.2020 14:00:19): backup completed: dbase-202009051355.gz (16.7M)

[staze]

Hi all,

This issue still seems to be occurring regularly.

Does this actually matter?

backup (05.05.2021 00:00:04): backup media size is 1.7G (1.6G free).
backup (05.05.2021 00:05:19): backup completed: dbase-202105050000.gz (18.5M)
export (06.05.2021 00:00:03): 6 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (06.05.2021 00:00:05): backup media size is 1.7G (1.6G free).
backup (06.05.2021 00:05:24): backup completed: dbase-202105060000.gz (18.5M)
export (07.05.2021 00:00:01): 7 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (07.05.2021 00:00:02): backup media size is 1.7G (1.6G free).
backup (07.05.2021 00:00:18): WAL file cannot be resolved, backup might be incomplete.
backup (07.05.2021 00:05:35): backup completed: dbase-202105070000.gz (18.5M)
export (08.05.2021 00:00:02): 8 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (08.05.2021 00:00:07): backup media size is 1.7G (1.6G free).
backup (08.05.2021 00:05:28): backup completed: dbase-202105080000.gz (18.5M)
export (09.05.2021 00:00:01): 9 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (09.05.2021 00:00:03): backup media size is 1.7G (1.6G free).
backup (09.05.2021 00:00:18): WAL file cannot be resolved, backup might be incomplete.
backup (09.05.2021 00:05:41): backup completed: dbase-202105090000.gz (18.5M)
export (10.05.2021 00:00:01): 10 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (10.05.2021 00:00:03): backup media size is 1.7G (1.6G free).
backup (10.05.2021 00:05:23): backup completed: dbase-202105100000.gz (18.5M)
export (11.05.2021 00:00:01): 11 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (11.05.2021 00:00:03): backup media size is 1.7G (1.6G free).
backup (11.05.2021 00:00:18): WAL file cannot be resolved, backup might be incomplete.
backup (11.05.2021 00:05:36): backup completed: dbase-202105110000.gz (18.5M)
export (12.05.2021 00:00:01): 12 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (12.05.2021 00:00:02): backup media size is 1.7G (1.6G free).
backup (12.05.2021 00:05:21): backup completed: dbase-202105120000.gz (18.5M)
export (13.05.2021 00:00:01): 13 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (13.05.2021 00:00:17): backup media size is 1.7G (1.6G free).
backup (13.05.2021 00:05:33): backup completed: dbase-202105130000.gz (18.5M)
export (14.05.2021 00:00:00): 14 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (14.05.2021 00:00:16): backup media size is 1.7G (1.6G free).
backup (14.05.2021 00:05:44): backup completed: dbase-202105140000.gz (18.6M)
export (15.05.2021 00:00:04): 15 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (15.05.2021 00:00:09): backup media size is 1.7G (1.6G free).
backup (15.05.2021 00:05:35): backup completed: dbase-202105150000.gz (18.6M)
export (16.05.2021 00:00:00): 16 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (16.05.2021 00:00:02): backup media size is 1.7G (1.6G free).
backup (16.05.2021 00:00:17): WAL file cannot be resolved, backup might be incomplete.
backup (16.05.2021 00:05:36): backup completed: dbase-202105160000.gz (18.6M)
export (17.05.2021 00:00:16): 17 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (17.05.2021 00:00:17): backup media size is 1.7G (1.6G free).
backup (17.05.2021 00:05:38): backup completed: dbase-202105170000.gz (18.6M)
export (18.05.2021 00:00:01): 18 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (18.05.2021 00:00:02): backup media size is 1.7G (1.6G free).
backup (18.05.2021 00:00:17): WAL file cannot be resolved, backup might be incomplete.
backup (18.05.2021 00:05:36): backup completed: dbase-202105180000.gz (18.6M)
export (19.05.2021 00:00:01): 19 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (19.05.2021 00:00:02): backup media size is 1.7G (1.6G free).
backup (19.05.2021 00:00:18): WAL file cannot be resolved, backup might be incomplete.
backup (19.05.2021 00:05:38): backup completed: dbase-202105190000.gz (18.6M)
export (20.05.2021 00:00:07): 20 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (20.05.2021 00:00:08): backup media size is 1.7G (1.6G free).
backup (20.05.2021 00:00:23): WAL file cannot be resolved, backup might be incomplete.
backup (20.05.2021 00:05:36): backup completed: dbase-202105200000.gz (18.6M)
export (21.05.2021 00:00:01): 21 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (21.05.2021 00:00:04): backup media size is 1.7G (1.6G free).
backup (21.05.2021 00:00:19): WAL file cannot be resolved, backup might be incomplete.
backup (21.05.2021 00:05:37): backup completed: dbase-202105210000.gz (18.6M)
export (22.05.2021 00:00:01): 22 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (22.05.2021 00:00:02): backup media size is 1.7G (1.6G free).
backup (22.05.2021 00:00:17): WAL file cannot be resolved, backup might be incomplete.
backup (22.05.2021 00:05:36): backup completed: dbase-202105220000.gz (18.6M)
export (23.05.2021 00:00:01): 23 lines of data written to file: NOAA-monthly-imp-202105-day.txt
backup (23.05.2021 00:00:02): backup media size is 1.7G (1.6G free).
backup (23.05.2021 00:00:18): WAL file cannot be resolved, backup might be incomplete.
backup (23.05.2021 00:05:36): backup completed: dbase-202105230000.gz (18.6M)

[admin]

To be honest, I never tested if a non resolved WAL file makes the backup inconsistent anyhow.
I expect not, it might just not have the very latest changes written into the DB.

[staze]

Do we know why it can’t resolve/find the WAL? It sure looks like it’s there…

[Gyvate]

a) it might not have been there when the log entry was written (automatically purged, ...)

b) I wouldn't worry too much about it as Meteobridge doesn't use (by default) continuous Archiving and Point-In-Time Recovery - that's where a WAL file comes into place. And you would have to set up this PITR yourself.
(by the way, I also have this message once in a while).

A WAL (=Write Ahead Log) file usually records all transactions since the last backup, so in principle you could rebuild your database to any point in time between your last backup and (e.g.) a system crash - but that needs some skill and deeper knowledge of the process. In professional environments that's common practice (an ORACLE database calls this WAL their ReDo logs).
But here the WAL file would only contain transactions which occurred between start of backup and end of backup. These will be covered with the next backup and won't get lost (unless the system [precisely your database] crashes in between). From your log we are talking about a 5 minute time frame. If you don't have minute based archiving active, it won't concern you at all.
If you have e.g. a (database) crash, your backup policy (once a day) will have a maximum possible data loss of one day [if the crash occurs 23 h 59 m after the last backup] (unless you know how to rebuild the database from a WAL file - and want to do this). Backup once an hour will reduce this risk significantly.

If you want to take a deep(er) dive into the matter, look up e.g. http://www.mit.edu/afs.new/sipb/project ... iving.html