I have implementation where i need to support total around 25 - 50 TB of data in alfresco. I am planning to create around 50 tenants and each tenant having data upto 500GB to 1 TB. So for this design what all are the things I need to take care?
The size of content is fairly irrelevant and should not be a problem. The limits are not imposed by Alfresco so as long a s you are using a fairly modern filesystem (for example NTFS rather than FAT16) and you have enough disk space you should be O.K.
You may want to consider putting each tenant's content store on a separate disk or volume? And I'd suggest you look at some disk management tools.