how large of a volume

[Jason Kiebzak]

Hello Folks,

How large of a volume can I create with s3backer? Can I create 1 PB volume?

Thanks

Jason

[Archie Cobbs]

Block numbers are unsigned 32 bit values. So the largest s3backer "file" size is whatever s3backer block size you chose multiplied by 2^32.

The s3backer block size can be whatever fits in a u_int, which is usually 32 bits. So in theory that means the s3backer "file" itself should be able to go up to 2^64 bytes.

Of course a 4GB block size would probably be kind-of unwieldy... Practically speaking, an s3backer blocksize of 4MB (instead of 4GB) is feasible. That would result in a limit of 2^54 bytes = 16PB.

But you also need to check the limit of how large the "upper" filesystem can be. That depends on your filesystem choice of course.

Here's info on that: https://en.wikipedia.org/wiki/Comparison_of_file_systems#Limits

-Archie

[Archie Cobbs]

And as a last resort, you could always just redefine s3b_block_t and recompile :)

[Jason Kiebzak]

thanks. What is the largest s3backer volume anyone has used successfully (or heard of)?