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Question concering Space Requirements in combination with immutable Capacity Tier (SOBR), Recommendations for Retention and Immutability

Hello everybody,

 

First, thank you for your input; I appreciate your help! I have the following question regarding space requirements for backups.

Here are the parameters:

  • B&R Version: 12.1
  • Performance Tier: Formatted with REFS, Cluster size 64KB
  • Capacity Tier (Wasabi): Versioning and Object Lock enabled
  • SOBR Configuration: Includes both the Performance and Capacity Tiers
  • Daily Backup Job:
    • Data size: 2 TB
    • Compression Ratio: 50% (resulting in 1 TB Data on the SOBR)
    • Daily Change Rate: 10% (resulting in 0.1 TB daily changed Data on the SOBR)

Case 1:

  • Backup Job Data Retention: 21 Days
  • Immutability: 10 Days

Space Requirement Calculation for Capacity Tier (Wasabi):

Backup blocks can be deleted after:

Retention Period(21 days)+Immutability Period(10 days)+Block Generation Period(10 days)=41 

Space requirement: 1 TB+(40 days×0.1 TB/day)=5 TB

 

Case 2:

  • Backup Job Data Retention: 10 Days
  • Immutability: 3 Days

Space Requirement Calculation for Capacity Tier (Wasabi):

Backup blocks can be deleted after:

Retention Period(10 days)+Immutability Period(3 days)+Block Generation Period(10 days)=23 

Space requirement: 1 TB+(22 days×0.1 TB/day)=3.1 TB

 

Is this calculation correct? Any input is highly appreciated! What are your settings / recommendations?

 

Thank you!

 

 

Andreas

5 comments

coolsport00
Userlevel 7
Badge +19

Hi @Andreas Holzinger -

Generally speaking...from what I can tell by first reading through it, it looks like you got all your ‘ducks in a row’ so to speak. All looks good to me.

Keep in mind regarding immutability, and you do have this stated above as far as days for it goes… but retention for immutability is such that the start of it begins AFTER THE LAST RESTORE POINT FOR AN ACTIVE BACKUP CHAIN IS CREATED. So, you’ll need to keep that in mind as well. Veeam has a calculator you can play with to help, if you haven’t seen it yet. It’s new:

https://calculator.veeam.com/vse/

It does have immutability option in it as well. I’ve not played with it myself, so can’t comment on it from personal experience.

Shane Williford - Veeam VMCA/VMCE | Veeam Legend | VUG Leader | VCP-DCV | Twitter: @coolsport00
Chris.Childerhose
Userlevel 7
Badge +21

Yeah your calculations look good based on how retention works with Immutability.

Recommendations - this is subjective based on your RPO/RTO and SLA requirements.  So keep that in mind when setting this up.

Chris Childerhose - VMCA2024 | VMCE2023 | Veeam Vanguard 7* | Veeam Legend 4* | vExpert 5* | VCAP-DCV/VCP-DCV | Object First Ace | Cisco Champion | Twitter: @cchilderhose | Blog Site – https://just-virtualization.tech
A
Userlevel 1

Thank you for your help!! 

 

One more question:

Is it possible to lower the immutability on an existing backup? For example from 14 days immutability to 7 days immutability. 

Thanks for getting this sorted out!

 

Andreas

coolsport00
Userlevel 7
Badge +19

Yes. 7 is the minimum amount, if I’m not mistaken (can’t go lower than that).

Update:

Yep 🙂 https://helpcenter.veeam.com/docs/backup/vsphere/hardened_repository_immutability.html?ver=120#immutability-for-image-level-vm-and-physical-machine-backups

Shane Williford - Veeam VMCA/VMCE | Veeam Legend | VUG Leader | VCP-DCV | Twitter: @coolsport00
dloseke
Userlevel 7
Badge +6

Do note that if you lower the immutability period on an existing backup, it’ll only affect restore points moving forward.  Those restore points that have already been written with the longer immutability flag will still be subjected to the original flagged period and not the new shorter period you set.  Doing so would create a vulnerability where the flag could be decreased and then the files modified/deleted, so clearly we wouldn’t want that.  So the point is, set that period with much thought and intention, because it takes a good long while to decrease it (case in point, a bucket I have in Wasabi that has very little data, but it’s flagged for a year, so I can’t delete it and clean up until that expires).

Derek M. Loseke, Senior Systems Engineer | Veeam Legend 2022-2023 | VMSP/VMTSP | VCP6-DCV | VSP/VTSP | CCNA | https://technotesanddadjokes.com | @dloseke

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