Cache Sizing for Object Storage Clarity

[micoolpaul]

Hi all,

Feeling a bit blindsided by the quiet messaging on this feature.

On initial documentation release of v12, no mentions or advice was given on sizing considerations for NAS Backup cache repository when doing NAS Backup to Object Storage
https://web.archive.org/web/20230214231 ... ml?ver=120

Then at some point between February and May, the guidance is updated to recommend allocating not less than 1.5GB of disk space per 1 Million files protected by NAS Backup job (understand as well that duplication of protecting files between jobs also means extra storage required).
https://web.archive.org/web/20230531120 ... ml?ver=120

Now the guidance says that you require 1GB of disk space for active metadata per 1 Million files.

Whilst this is a change from the 'Veeam Best Practice' guidance of 4GB being sufficient, suddenly the 'Veeam Best Practice' documentation has been updated to state you require 5% of the source data size, as your cache drive. This suddenly changes architectures dramatically. As 50TB of data has gone, without any real announcement that I've seen, from ~4GB to ~2.5TB! That's a huge uplift in cache storage, made dramatically more expensive by the strong recommendations to store the cache on SSD.

Apologies if I've missed anything on this topic, but I don't recall any statements from Veeam on these requirements, and this is a big change that I'd appreciate an extra review of guidance on.

[Gostev]

Hi, Mico. It's unclear what document are you referring to. The links above don't work either.

[micoolpaul]

Hi Anton, sorry don’t know what’s going on with those links. Let me reset the conversation here.

I’ve worked on a project that utilises NAS Backup to object storage. Historically the only sizing guidance for the cache repository has been the veeambp.com guidance. And this was that you only need a few GBs of capacity for the NAS cache repository in a NAS backup architecture.

When v12 launched, the helpcenter documentation system requirements page had no special sizing guidance for NAS backup to object storage

The helpcenter documentation now (https://helpcenter.veeam.com/docs/backu ... repository
) has a sizing recommendation of 1GB of cache repository space per 1 million files. The internet archive links I attempted to share also showed a previous version of the same system requirements page that stipulated you needed 1.5GB of cache repository per 1 million files, and the other link showed the original launch documentation that didn’t have any sizing guidance at all on this topic.

However, in the current veeambp.com site, which finally supports vbr v12, a guidance is recommended to size the cache repo with 5% of the source share size.

Link for ease: https://bp.veeam.com/vbr/2_Design_Struc ... cache.html

Depending on file version expectations etc it feels dramatically over spec’d that in one of the examples on the Veeam BP link, 50TB source data, 300 million files, the veeambp.com website recommends 2.5TB of NAS cache storage, but (and it gets messy not knowing number of excursions) if we start with the 300 million file number, according to help centre sizing we’d only need a minimum of 300GB (we can’t be more specific until we look at number of file versions)

Hope this makes more sense

[Gostev]

Thanks for the clarifications. In general, the Help Center is the ultimate source of truth as this is what technical writers verify with the responsible teams.
While the BP site is more of a community project, it is not guaranteed to be up to date and it's definitely not reviewed by QA.

[micoolpaul]

Thank you Anton!

Shall stick to the Help Center as the minimum mandated capacity in this scenario and add extra buffer space on top!