While creating multi-volume database, actual sizes of volumes are not corresponding to the number of pages set in RDB$FILES

set sql dialect 3;
create database 'c:\testmulti.fdb' user 'sysdba' password 'masterkey'
page_size 4096
length 1000
FILE 'c:\dbmv1.fd1' length 2000
FILE 'c:\dbmv1.fd2' length 3000
FILE 'c:\dbmv1.fd3' length 4000
FILE 'c:\dbmv1.fd4' length 5000;

create generator g1;
create table t1(c1 varchar(100));
insert into t1(c1) values ('test test test testtttttt test');
insert into t1 select * from t1 where gen_id(g1, 1)<1000000;
exit;

As a result, database files were created

29.06.2009 00:25 8 216 576 DBMV1.FD1 2006 pages
29.06.2009 00:25 12 357 632 DBMV1.FD2 3017 pages
29.06.2009 00:25 16 453 632 DBMV1.FD3 4017 pages
29.06.2009 00:25 38 703 104 DBMV1.FD4
29.06.2009 00:25 4 190 208 TESTMULTI.FDB -1023 pages