Modify production environment backup recommendation

[AkshayGadhaveRH]

Since online backups are supported for production, after snapshot backups were dropped [1], removing the now irrelevant line about online backups being unsupported. [1] https://issues.redhat.com/browse/SAT-25667

JIRA: https://issues.redhat.com/browse/SAT-29507

What changes are you introducing?

Why are you introducing these changes? (Explanation, links to references, issues, etc.)

Anything else to add? (Considerations, potential downsides, alternative solutions you have explored, etc.)

Checklists

• I am okay with my commits getting squashed when you merge this PR.
• I am familiar with the contributing guidelines.

Please cherry-pick my commits into:

• Foreman 3.14/Katello 4.16
• Foreman 3.13/Katello 4.15 (EL9 only)
• Foreman 3.12/Katello 4.14 (Satellite 6.16)
• Foreman 3.11/Katello 4.13 (orcharhino 6.11 on EL8 only; orcharhino 7.0 on EL8+EL9; orcharhino 7.1 with Leapp)
• Foreman 3.10/Katello 4.12
• Foreman 3.9/Katello 4.11 (Satellite 6.15; orcharhino 6.8/6.9/6.10)
• Foreman 3.8/Katello 4.10
• Foreman 3.7/Katello 4.9 (Satellite 6.14)
• We do not accept PRs for Foreman older than 3.7.

[github-actions]

The PR preview for ad0f091 is available at theforeman-foreman-documentation-preview-pr-3747.surge.sh

The following output files are affected by this PR:

• Administering_Project/index-foreman-deb.html
• Administering_Project/index-foreman-el.html
• Administering_Project/index-katello.html
• Administering_Project/index-orcharhino.html
• Administering_Project/index-satellite.html

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[maximiliankolb]

style-wise LGTM.

[evgeni]

Line 4 reads "Perform an online backup only for debugging purposes." -- this should also be gone.

I would also re-word the "risks associated" paragraph, but don't have a good suggestion right now.

[bangelic]

Line 4 reads "Perform an online backup only for debugging purposes." -- this should also be gone.

I would also re-word the "risks associated" paragraph, but don't have a good suggestion right now.

Just a suggestion to reword the "risks associated" paragraph:

When you perform an online backup, the procedure repeats the Pulp database backup until no processes are altering the database.
Because the Pulp database takes the longest to back up in the {Project} backup, any changes to it during this process restart the backup.

[evgeni]

Thanks Brian! This definitely reads easier than the previous version.
My concern however was more about the fact that the whole statement is not actually correct.
It's not the Pulp database (PostgreSQL), it's the Pulp data (/var/lib/pulp) that we watch for modifications and re-try the backup if we notice any.
Additionally (and that's why we consider online backup production ready now) we now ensure that no "normal" operations happen during the backup, so the chances that something changes the pulp data are rather small.

So how about this:

When you perform an online backup, most {Project} services remain running and usable.
To ensure a consistent backup, background workers are shut down and operations that require those remain in pending state.
Additionally the backup process ensures that the Pulp data (`/var/lib/pulp`) is not altered during the backup.
Any changes to the Pulp data during the backup will result in restart of the backup process, taking additional time.

[bangelic]

Thanks Brian! This definitely reads easier than the previous version. My concern however was more about the fact that the whole statement is not actually correct. It's not the Pulp database (PostgreSQL), it's the Pulp data (/var/lib/pulp) that we watch for modifications and re-try the backup if we notice any. Additionally (and that's why we consider online backup production ready now) we now ensure that no "normal" operations happen during the backup, so the chances that something changes the pulp data are rather small.

So how about this:

When you perform an online backup, most {Project} services remain running and usable.
To ensure a consistent backup, background workers are shut down and operations that require those remain in pending state.
Additionally the backup process ensures that the Pulp data (`/var/lib/pulp`) is not altered during the backup.
Any changes to the Pulp data during the backup will result in restart of the backup process, taking additional time.

Looks good, Evgeni. The only suggestion I would make is to change the last sentence to:
Any changes to the Pulp data during this process restart the backup, taking additional time.

[AkshayGadhaveRH]

Thanks @bangelic ! I have edited the para as per your and Evgeni's recommendation. However, I have kept the last line as per Evgeni's suggestion and tweaked the To ensure a consistent backup, line a bit.