My company just started testing Wasabi as opposed to AWS S3 storage about two weeks ago, and we are greatly interested in thoughts on this topic as well.

From the info I have it will depend on what pricing tier you have for what constitutes the 'best practice' settings.

If you are using the Wasabi 'Pay As You Go' option it has a 90d deletion policy. Any data you delete prior to the 90d since initial upload is billed at the full active storage rate until 90d is up. We underestimated this and had to alter our backup policies as our costs were on track to be quite a bit higher then Amazon S3 costs. Until we can get more of a feel for how this affects us we have changed our full backup policy from every month to every three months.

If you are big enough >25TB of active storage then you should opt for their Wasabi Reserved Capacity Storage, you get a bit of a discount and they change the deletion policy to 30d as opposed to 90d.

The company I work for does not have the requirements for >25TB as of right now. I am in talks to see if they would allow a smaller reserved capacity (maybe 5-10TB) if we agree to a longer term.

Retention should always be set according to your business needs. You did not state how long you need to keep backups for your customer, so I'l just assume 60 days is all you need. You can, of course, keep fewer backups and costs will not change. Early deletion costs are the same as you'd pay if the data remained. Having said that...

• Full backup once per month - That works - every 30 days
• Block level in between - Yes. Incremental backups in-between
• Delete versions older than? 60 days works. After 90 days, the first 30 day backup set can be removed
• Always keep the last version - Yes, if that's what you need for old backups on systems that are not being actively backed up
• Keep number of versions - ignore this option

Another option is to utilize Backblaze S3 Compatible storage. Cost is $.005 per GB per month and there is no minimum retention period. Since we only keep one monthly version of images/HyperV Vhdx files in the Cloud (vs. 90 days for files), Backblaze is ideal. We keep local Daily image/VHDx copies, and consider the monthly VHDx/Image to be a Disaster recovery solution.

We had looked at Backblaze B2 however at the time the Synthetic Full Backup was only an option for MSP360 when using AWS or Wasabi. The Synthetic Full Backup is a critical feature do to the limited bandwidth of the internet connection in our geographical area.
My understanding is Synthetic Full Backup is available for Backblaze B2 in the newer v7 client that is not yet available to MSP360.

Reply clarified in next post

I am verifying, but I know it's supported in 6.x and everything I have for 7.0 says the new backup format also supports Synthetic Fulls for Image as well as File and Virtual. You would need to use the Backblaze S3 Compatible connector to see the Synthetic Full option.

I am thinking what you are now saying is that Backblaze B2 S3 support is not available yet for Managed Backup customers.. and that is true. I am trying to get an ETA and will reply back as soon as I hear.