Ajouter une option pour désactiver la compression de sauvegarde

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21

Note to self:

Recently hit space issues again and backups failing so this post needs revisiting soon.

Note that in order to create a backup resulting in a 12GB gzip file I require ~36GB+ of space dedicated to backups, ~24GB+ of free space:

  • 12GB for the backup from the day before
  • 12GB for the new backup file
  • ~12GB+ tar archive to be compressed into gzip file (original DB file backup + original image files

So as backup sizes increase by 1GB, the backup / space requirements are actually increasing by a ~3GB.

This assumes that you are only keeping a single previous backup - where the Discourse setting maximum backups is set to 1.

The Discourse default is 5, so using defaults I would need ~84GB dedicated to backups to allow them to work.

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What is the lion’s share of the backup? I assume uploaded images and so on? Wouldn’t it be easier to specify the backup is database-only, and thus make it a tiny fraction of the overall size?

(Yes, we’d still need some way to back up the images independently, but at least then the urgent need for 100GB+ of space would not be present.)

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Yes the lions share of the backup content is “uploads”.

However a backup is not complete without the “uploads”.

My personal target is to move the images / “uploads” to Amazon S3 to avoid this issue for this specific instance, however there is still some testing to be done on a high topic / post count instance before I can trust the migration to S3, some issues already highlighted in that thread (more specifically avoiding a rebake of all posts).

I have other Discourse instances that would benefit in the backups being created in a more streamlined way.

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I have the same problem as this thread, I have many GB of images and while I want to migrate them to S3 from what I have read the migration script seems a bit buggy still. So, I still have images locally but am running out of disk space given the high ceiling needed to allow a backup. Even if I could delete the old backup before creating the new one it would be OK for me. In fact I have been doing that manually.

Note that the backup system also seems to be failing me on the free disk space calculation, it will fill up the whole disk before giving up, and not even delete the partial files. Then the whole computer gets unhappy. There should be a calculation to not do a backup if there is no disk space for it, taking into account the space needed for the compression etc.

Edit: I am going to run a cron job which will delete the (sole) local backup every day. That should solve my immediate problem, but I think it would also be nice to have an option to immediately delete any (local) backup that was already successfully copied to S3.

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Quelles sont les options gzip actuelles utilisées pour la compression des sauvegardes ?

Contrairement à ce qui est mentionné dans le sujet, je cherchais à économiser de l’espace en utilisant une méthode de compression plus efficace. J’ai effectué quelques tests rapides et approximatifs sur notre dump SQL avec différents niveaux de gzip et aussi avec brotli.

2630702226 level1.sql.gz
2276305530 level1.sql.br
2216602536 level5.sql.gz
2147212204 level9.sql.gz
2036157791 level2.br
1851831279 level4.br

Comme on peut le constater, Brotli niveau 4 surpasse largement Gzip niveau 5 en termes d’efficacité, tandis que le temps de compression reste dans la même fourchette. Le résultat de Brotli niveau 1 n’était pas mauvais, compte tenu de la rapidité fulgurante de cet outil.

Quoi qu’il en soit, je trouve des gains de 10 % ou plus tout à fait intéressants.

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Intéressant, quels étaient les temps de compression réels ? :thinking:

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Zopfli sera plus intéressant ici, car il est compatible avec les outils de décompression gzip standard. Brotli nécessite un décompresseur différent.

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zopfli est effroyablement lent, je doute que nous souhaitions l’utiliser pour quelque chose comme une sauvegarde massive. En revanche, brotli est au moins partiellement optimisé pour la vitesse.

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\u003cniveau de compression gzip de sauvegarde pour les téléchargements
est-il possible de désactiver la compression gzip. puisque mes téléchargements sont principalement des images déjà compressées, c’est une perte de ressources et de temps d’essayer de les compresser à nouveau.

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D’un fil de discussion connexe :

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