Weekly Classic Computer Trivia Question (20150410)

ANDY HOLT andy.holt at tesco.net
Fri Apr 10 12:03:10 CDT 2015


> 
> True or False:
> 
> The ZFS file system wastes more space on an average file allocation than
> the ram in a typical PDP-8.

Given a few assumptions:
a) ZFS set up with default block size
b) you mean "typical"
c) On average, half the last block of a file is wasted
d) AFAICT ZFS doesn't use the trick used by some *ix filesystems of packing the data contents for small files into the directory.
    (to do so would clash with the reliability focus of ZFS)

Then:
 A typical PDP8 had 4 or 8K words (thus 6 or 12K bytes)
 Very few PDP8s had more than 32K words (48K bytes)
all of which are less than half the size of the default fs blocksize for ZFS.

Andy




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