Rik's Blog

Those that know me, know I've had a server running at home for some time. Nothing special, but just lots of harddisks - runs a torrent daemon, DNLA/UPNP software - basically central storage and serving for everything I've got.

However there were faults with it.

1. Noisy - the Fan on the CPU was too loud, time to replace it.
2. Too many hot hardisks - some low capacity
3. Not all the same size hard disks - so no RAID
4. No redundancy so every time there's an electrical storm I run the risk of another disk blowout
5. Low memory - 2GB

An opportunity arose to upgrade the CPU to a quad core i7, (from an old core 2 duo E6300) - so got a new motherboard, CPU was free, 8GB of DDR3, and 4x 2TB Green SATA2 harddisks. Total cost - just €440 delivered!

So I've stripped out the old mobo/cpu/memory and harddisks and installed all the new gear. Case is now much more streamlined (going from ATX to mATX) as I've less drives, etc. Big Q now is what to run on it....

To solve pain point #4 above I need RAID. I could use the Intel chipset to do a RAID 1 reducing my 8TB to 4TB but with full backups. Seemed a bit pointless to me to waste 2 disks on redundancy. So ideally RAID5 is needed. And this is where I started to do a little more searching/thinking... There are 2 ways to do RAID - hardware or software. Each has some gotchas, as well as pluses obviously.

For hardware I had a choice - use the Intel stuff, which didn't have RAID5, or buy an external controller. Unfortunately even cheap controllers aren't cheap - about €160 (1/3 of my system price), and good ones are even more expensive (almost the same price again!). While Hardware gives you performance, your at the mercy of the vendor in ensuring compatability of your RAID set on future products if something were to go wrong - e.g. try taking a RAID set from one Intel chipset to another - it doesn't work. Independent RAID cards are a bit better this way - btu your still at their mercy.

So what about software.. Well things are a bit better here. You can always go back and get the software - even possibly an archive of a full distro with the right drivers and software - so in theory it's a lot less risky. But the downside is performance. You now have to use your CPU much more to do the overheads of the RAID algorithm, and write to the individual disks. Lucky me that I've managed to score a nice i7 for my troubles

Which left me looking at solutions. Time and time again it came back to ZFS being the best performing of the lot. However now I had a dilema. ZFS is supported on OpenSolaris, Linux and FreeBSD (as well as Mac OS-X but not gonna run that). Which to pick...

Linux I'm most familiar with. Linux ZFS support has issues, but is developing quite rapidly - 3 solutions exist, 2 native ZFS (zfsonlinux and kqstor)and a FUSE (zfs-on-fuse) implementation. It's been gathering pace and catching up on features but for the most part the impression I get by googling is that the FUSE version isn't efficient, and the native one isn't reliable. Which kind of defeats the purpose of choosing it. I could always go with MD driver on Linux, but I've ruled that out for now as I'd like to get the performance of ZFS if I can

I had a quick look at OpenSolaris - and there is still some activity - particularly on EON the NAS version. However, with Oracle effectively killing it last year it's hard to recommend using it.

And finally - freeBSD. 3 Install options are open to me - freeBSD release itself which actually has quite an old, but stable ZFS support (ZPool version 15), freeNAS which is based on freeBSD, or PC-BSD which is a desktop based distro. From a freeBSD install there are mechanisms, like nanoBSD, to reduce the install down to a USB pendrive. And this is what the freeNAS guys have also moved to - then add their magic on top. Unfortunately again, the ZFS version is still only version 14/15. FreeNAS is undergoing a lot of development now as it moves to use nanoBSD and get it's GUIs updated, etc. It's really nice and worth a look. And finally PC-BSD, it's a desktop version of freeBSD - requires a large install, but looks nice - may even just look for myself.

In conclusion - for latest ZFS versions Linux or OpenSolaris are ahead of the game right now. FreeBSD will get an update to v28 at some point - it's just a matter of time. I may be coming down too hard on the Linux versions, but impressions are slow or unreliable.. I may just have to test them to see which is better. And finally OpenSolaris - is it truly dead?

I'll be sampling these over the coming days/weeks and hope to blog about experiences.

First up FreeNAS 8.0 RC4