Looking for a Text on ZFS

Wojciech Puchar wojtek at wojtek.tensor.gdynia.pl
Sun Feb 3 08:56:08 PST 2008

> I already read that before I posted my question. Neither by this text,
> nor by the one in the Wikipedia could I participate in the exitement
> around ZFS. Ok, so it's a 128Bit FS. Big fat, hairy deal! I couldn't see

that's like 64-bit soundcards that have to be "better" than 32-bit, while 
most of them was unable to actually get past 13-14 bit (most past 12) with 
it's signal to noise ratio.

> any advantages in using it instead of FFS (UFS), but I thought I was

ZFS is "better" because:

1) you make create 1000 of "filesystems" without partitioning. so lots of 
"admins" that think more partitions=better are happy. you may set quota 
for each "filesystem"

2) it takes many drives to the pool and you may add then new drives.
same as gconcat+growfs.

3) it doesn't have per user quota, which creates a problem that is 
"solved" by 1), and you have to create at least one filesystem/user, which 
then is said to relieve admininstrator from work ;)

4) ZFS says that hardware checksums are not enough and disk hardware may 
be buggy so then "solve" this problem checking everything with CPU.

while i've had failing drives many times i never seen it reading bad data 
and not reporting error.

5) you don't have to wait for fsck. one of the few real adventages.
Anyway - FreeBSD doesn't crash like windoze, so it's not that big thing.

6) zfs set copies= works only on writes, but scrub doesn't make a 
missing copy when one is failed.

so the best possible adventage (setting what file to mirror, what not) is 

7) there is no per file encryption, while it's said it will be SOON ready.

8) ZFS is clear winner on artifical tests like creating miliion of small 
files and then deleting them etc..

9) ZFS is very fast, just add more RAM and faster CPU.

i would - to make more RAM and CPU power available for programs i run, not 
to be wasted.

there was a lot of excitement here after ZFS was ported, but i think it's 
time too see that 20 (or more?) year old UFS is still a winner.

i think some changes in UFS, like larger cylinder groups (so there won't 
be 10000 of then on big filesystem), possibly dynamic allocation of 
inodes, would be good. but not critical :)

More information about the freebsd-questions mailing list