wouldnt this be a lot of wasted space on the filer? 2.5x?
That's why I like thin provisioning. 2.5x factor probably comes from fractional reserve being kept at 100% - current official best practice recommends setting it to 0% (with a lot of caveats)
what does the -s option do for creating volumes?-s none, volume, file
none -> thin provisioning, i.e. only actually used space is taken from the aggregate
volume -> fat provisioning, i.e. full space reserved upfront from the aggregate
file -> never use