barman compression error

[fchapuis0101]

Hi,
I've got this error message in postgres log
WARNING: gzip option is deprecated and will be removed in future versions. For WAL compression, please make sure to enable it directly on the Barman server via the compression configuration option
2025-08-13 15:26:30.962 CEST [3577794]: [207-1] user=,db=,client=,application= LOG: restored log file "000000320000399D00000096" from archive
in barman configuration compression = gzip is set
the restore_command is: restore_command: /usr/bin/barman-wal-restore -U barman -z -p 8 barman-a2s13-101 pg_cluster %f %p
I change the barman conf. with bzip2 and restore_command with -j option but the error message continue to be displayed

Any help will be very appreciated

Regards
Fabrice

[gustabowill]

Hey @fchapuis0101

The purpose of the compression flags (--gzip and --bzip2) in barman-wal-restore is primarily client-side decompression, it says "give me the WAL file compressed with this algorithm and decompress it locally once arrived". However, the usage of these flags can cause some weird scenarios e.g. if your WALs are already compressed in the Barman server with a different algorithm, it will decompress -> compress with the request algorithm -> transfer the file -> decompress once arrived in the client.

Such behaviors are very cumbersome to manage so we agreed that it would be better to centralize the way that compression is requested on Barman. Ideally, one should enable compression directly in the Barman server, not on barman-wal-restore, that's why we deprecated those flags. If you want the file to be decompressed on the client and not on the server, you can use the --keep-compression flag, which was introduced exactly for this purpose.

This is essentially what that message is saying. Let me know if you have any further questions.

[fchapuis0101]

Hi, thanks for answering, I try with --keep-compression on the client side and lz4 on the barman server, but same problem, the error persists in the postgres log

[gustabowill]

That warning message is only displayed when explicitly specifying one of the compression flags on barman-wal-restore. If you're just using --keep-compression it should never be displayed. Are you sure you're not seeing old log messages?

[fchapuis0101]

I will put the keep-compression option and check again the log. Thanks for your help