Поделиться через


Third Party RBS provider corrupting images in Office documents

 

Recently, I was working with a customer where they complained of images rendered corrupt in SharePoint document libraries. If you take the busted document and save it as a .zip file and see the media folder, the image will be corrupted. If you try to open it, you will get a message that the image is corrupt. Now, after researching, I found the issue to be with the third party RBS provider. The third party RBS provider was corrupting the images during save to the disc. Nonetheless, the third party provider quickly provided a hot fix, and the issue was resolved.

Having said so, I relaized that there are many misconceptions about RBS. It is not my goal to explain what RBS is as there is a lot of information about it. There are some misconceptions that I want to address.

Is RBS is a silver bullet for content database size?

RBS would not be a mechanism to reduce content database size. As per the boundaries and limits. If you are using Remote BLOB Storage (RBS), the total volume of remote BLOB storage and metadata in the content database must not exceed the boundaries specified in the link. https://technet.microsoft.com/en-us/library/cc262787(v=office.15).aspx#ContentDB

By using RBS can I reduce the time for database backup and restore?

The answer is no. RBS adds complexity for the backup and restore, AND, RBS must be backed up in synchronization to maintain references consistency. The backup time = time taken to back up content db. + Time to back up RBS. If you look at the section “Implications of using RBS over the IT life cycle” at https://technet.microsoft.com/en-us/library/ff628583(v=office.15).aspx , RBS adds complexity for the backup and restore, AND, RBS must be backed up in synchronization to maintain references consistency. Here is an excerpt, For example, using a remote RBS provider will require increased IT operations complexity and some cost increases. This is because the content database and the BLOB store must be backed up in synchronization to maintain references consistency

Does RBS remove the 2 GB file size limit?

No, it does not.

Third Party RBS providers, shredded storage and RBS threshold!

With OOB FILESTREAM either everything is in RBS or nothing. With third party providers, you can specify thresholds. For example, if the content size > 1MB move it to RBS.

Now consider RBS with Shredded storage. By default, shredded storage will slice files that are SharePoint aware (e.g. Office documents) to 64 kb chunks; others (zip and media) to 1MB chunks. So, if you use a third party RBS provider you can set the threshold to 1MB and all media and zip files will move to RBS and all office documents will move to content DB. Note: Office documents will never go to RBS because the split size of 64KB is less than the threshold. I am not suggesting that you use such a threshold to simply keep all office content in SharePoint and everything else in RBS.

Final thoughts

RBS is not a mechanism to reduce content database size and does not reduce the backup and restore time. In fact, it adds complexity. I would consider RBS solely for storing real blobs like media files, other very large files and for Records management. It is preferred to have most of the content in the content database along with a proactive approach for data retention and archival which is a topic for some another day.