use strict;
use warnings;

open my $fh, q{<}, \ <<__EOF__ or die qq{open: < HEREDOC: $!\n};
>>> prd1703
Filesystem                                  Size  Used Avail Use% Mounted on
/workspace                                  3.9T  687G  3.2T  18% /workspace/data
>>> prd1701
Filesystem                                  Size  Used Avail Use% Mounted on
/workspace                                  3.9T  887G  3.0T  13% /workspace/data
>>> prd1702
Filesystem                                  Size  Used Avail Use% Mounted on
/workspace                                  3.9T  746G  3.1T  23% /workspace/data
__EOF__

print for
   map { unpack q{x4a*}, $_ }
   sort
   map {
       m{(\d+)(?=%)}
       &&
       ( ~ pack( q{N}, $1 ) . pack( q{a*}, $_ ) )
   }
   do  {
       local $/ = q{};
       split m{(?<!\A)(?=>>>)}, <$fh>;
   };

close $fh or die qq{close: < HEREDOC: $!\n};