[clue] ZFS on Linux?

[adam bultman]

On 10/31/2015 08:27 AM, Sean LeBlanc wrote:
> Anyone doing this? As many of you may or may not know, I dabble in the
> BSDs from time to time, and one of those more recent outcomes of that
> dabbling was a FreeNAS server I set up about 2 years ago to support Time
> Machine for macs as well as content for a Plex server.
>
> They give a bit more background on ZFS - I didn't realize that Snoracle
> took it closed source after acquisition, and that what is commonly
> called "ZFS" is probably really OpenZFS, and that Snoracle has their own
> version now, different than what the rest of world calls ZFS.
> ___________________________

For a lark (and for legitimate business purposes) I spent some time 
working with ZFS on linux, in it's two forms (more or less).

My server was a Dell Poweredge R900 (I think?);  quad proc, quad core, 
128GB of ECC RAM.  Boot drive was 5 or 6 of the built-in drives in a 
RAID5, with 2 SSDs for log and L2ARC.  I also had an 2 port emulex 10G 
NIC in it, too.  I tried multiple different shelves for running ZFS on - 
old Netapp shelves (FC connected DS14s, one with 500G ATA drives, 
another with 300G FC drives) and two SAS connected shelves of 300G SAS 
drives.  (Not all at once,  mind you.)

With CentOS6 *and* CentOS7, I couldn't get native ZFS to work 
reliably.   I also tried zfsonlinux, and that *also* didn't work 
reliably.  The system would basically crash if I *really* pushed the 
server hard or seemingly if the RAM cache got too full.

I was getting ready to blame the RAM (but it checked out with memtest86, 
multiple times) or the 10Gb NIC, but when I installed FreeBSD on the 
server and tested some more, it worked *perfectly*, and never once crashed.

I spent a decent amount of time trying to get ZFS working on linux - but 
to no avail.  Maybe I did something wrong several times in a row, and 
somehow the default FreeBSD setup is idiot proof - or something's wrong 
with my hardware and somehow I never hit the bug/problem running 
FreeBSD.   I have another box I'm going to test with (only 64GB of RAM, 
and 2 Intel X5550 CPUs) once I find the time to put CentOS 7 on it - and 
hopefully it'll work a whole lot better, since I have a large number of 
disk shelves sitting around, waiting to be used.



-- 
Adam