blocks, a new slab is created. If you update an existing item with data that is larger than the existing
block allocation for that key, then the key is re-allocated into a suitable slab.
For example, the default size for the smallest block is 88 bytes (40 bytes of value, and the default 48
bytes for the key and flag data). If the size of the first item you store into the cache is less than 40
bytes, then a slab with a block size of 88 bytes is created and the value stored.
by the chunk size factor until a block size large enough to hold the value is determined. The block size
is always a function of the scale factor, rounded up to a block size which is exactly divisible into the
chunk size.