Staggered snapshots

TrueNAS General
1

What is the recommended way to generate staggered snapshots? For example hourly that last for a couple days, daily that last a couple weeks, weekly that last a couple months, etc.

If you just create multiple separate schedules, is there a downside to having multiple snapshots taken simultaneously? So if the year starts with a sunday, I’ll have hourly, daily, weekly, monthly and yearly snapshots all taken at the same time at 0:00 on january 1st.

I tried to create a hourly schedule only from 1 to 23 (skip 0), and daily that skips the sunday, but then it fails because the weekly schedule doesn’t exactly fit in the monthly schedule.

2

ZFS snapshots are very efficient… so it should work fine.
Staggering then by 5 or 10 minutes each 12.00, 12.05, 12.10 etc would also work.

3

I try and avoid overlapping the timestamps if I can. here’s an example - one of our production systems has a schedule like this (datasets with SMB shares)

Hourly - Every hour from 1:00 to 23:00 - Lifetime 1 week
Daily - Every Night at 00:00 (excluding 1st day of each month) - Life of 4-12 weeks
Monthly - First of every month at 00:00 - Life of 6-12months

There for a really critical smb share (lots of activity and rollback of an hour could cost $$) - the dataset has:
Every 10mins (excluding on the hours - btw 6am and 10pm) - Life of 1 Day
Followed by the rest

The main reason we avoid doing all day for our 10min one - is it just limits the amount of snapshots in “Previous Versions” as we had performance issues at different times. On our 20/30min ver - we tend to use the whole day.

Edit: You could also limit your under hourly to biz days - such as monday to friday.

4

I’m not sure if there is an established recommendation.

BUT I’m trialing using minutely, hourly, daily, weekly, monthly.

The key is to have each snapshot task use a different naming scheme, ie auto-hourly, auto-daily etc

Each is a separate snapshot task. With progressively longer retention.

Minutely is actually 10 minutes and retained for 2 hours.

Hourly is retained for 2 days (or whatever I forget)

Etc.

I Replicate based on the hourlies or dailies, and use the “additional schemas” to pick up everything except the minutelies.

Replication snaps should have “allow empty” enabled. I disable empty on the minutely.

Turn on the replication task allow it to control life time on destination and hold pending snaps.

On the destination I run a separate snapshot task with 10 year retention and a different naming scheme.

5

Use different names for each snapshot task, such as:

  • auto-weekly_XXXXXX
  • auto-daily_XXXXXX
  • auto-monthly_XXXXXX

Also good practice to append the expiration lifetime at the end, such as:

  • auto-weekly_XXXXXX-6m
  • auto-daily_XXXXXX-1w
  • auto-monthly_XXXXXX-2y

This isn’t simply for better organizing, filtering, and searching.

:warning: It will prevent you from inadvertently destroying your snapshots, without even realizing it!

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