Azure Tape Library - Local Storage Requirements?

[kbeaulieu]

Hi all,

We are testing spinning up an Azure tape library using Starwinds VTL and offloading backups to blob storage as an offsite repository. We are trying to figure out how to calculate the amount of local storage we will need on the tape library in order to process our offsite backups. For instance, say we have a backup job that would be sized at 20TB for one full copy of each vm in the job. If I want to do a tape backup of that job, do I need to have local storage that can support up to 20TB? Or can I have, say, 5TB of local storage on the tape drive with, say, 5 tapes of 1TB each, and VEEAM will know that the tapes are full and swap them out for new tapes?

[Dima P.]

Hello and welcome to the community Kyle,

If I am not mistaken with Starwind VTL emulated tape can be replicated immediately after emulated tape media is being removed from the drive and once it's replicated it can be removed immediately. Try to estimate how many tapes are going to be processed simultaneously and make sure that predefined cache can allocate these tapes. Cheers!

[JammedFalcon]

Hello,

It depends on the configuration for backups that you have and how exactly you are doing backups. In case you are doing backup firstly to the backup repository on the host and then uploading it to the cloud you need to have enough storage for local backups. In case you are doing backups directly to the tapes, you need to calculate upload speed and how many time you spend for a backup job. In case of 20TB backup job, you can split tape as 1TB each if you have only 5 TB available storage. Then during writing backups to the second tape, StarWind Cloud Replicator must be able to upload the first tape and remove the local copy to create a new tape for this job. According to this, if you have good upload speed the first backup tape will be uploaded, StarWind VTL will create a new tape and Veeam will be able to use it as the next tape for the current backup job.