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#297862 - 03/05/2007 22:49 ultimate home RAID gizmo (random pondering)
DWallach
carpal tunnel

Registered: 30/04/2000
Posts: 3810
I'm not planning to pull the trigger on anything like this until early next year, so maybe this is all a huge waste of time, but what the heck.

I've currently got an Infrant X6 (more-or-less RAID5) box with 4x250GB of storage. We discussed this earlier, but I ended up just keeping the thing. It's basically full, and while it does the job, it's not exactly screamingly fast. NFS will never equal local disk performance, even over Gbit links. More importantly, it's simply too loud to leave on all the time. This is a pain, for all the reasons you can imagine. My front-end box is a Mac Mini, talking to the Infrant box with GigE (but not jumbo frames). And, yes, I've got the Infrant box on a UPS, which allows it to turn on all the disk caches.

I've been pondering how I want to improve on this situation. Initially, I was convinced that I'd end up with a MacPro Tower with four bigger disks in it. Those are quiet enough that they won't be annoying to leave on 24x7. Unfortunately, Mac OS X 10.4 doesn't support RAID5. Your only choices are mirroring, striping, or an external box like an Xserve RAID, or other RAID enclosures.

This got me poking around. The rumor mill is saying that OS X 10.5 will include ZFS, and there's some evidence from early developer builds to support that claim. If true, ZFS would easily do the RAID5 thing with a MacPro Tower's internal disks, and you'd get fast snapshots and all the other ZFS goodies as well. At that point, the only missing feature, relative to the Infrant box, would be it's easy setup and a handful of really nice features (e.g., an Infrant box will email you when a disk fails, among other events).

Of course, ZFS is natively at home in Solaris / OpenSolaris and has been ported to FreeBSD. ZFS hasn't shown up yet in FreeNAS (built on FreeBSD), but that's just a matter of time. And, for that matter, one of my dream features for the house I plan to buy in December (or thereabouts) would be a utility / wiring closet where I could have a rack-mount server, real wired Ethernet to every room, and so forth. At that point, the noise issues go away, and the Infrant box (or a sequel to it) looses one of the biggest strikes against it.

One way or the other, having a "real" computer is looking more attractive than the Infrant for my file server. Like it or not, I'm becoming one of these Apple walled-garden types, where the idea of all the Apple parts just snapping together and working is increasingly attractive.

Thoughts?

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#297863 - 04/05/2007 07:49 Re: ultimate home RAID gizmo (random pondering) [Re: DWallach]
LittleBlueThing
addict

Registered: 11/01/2002
Posts: 612
Loc: Reading, UK
I think you know that I'm a solid linux fan so do take that on board

IIRC one of the concerns is "what if it all goes wrong".

How many people do you know who can help if your ZFS system goes titsup?

Are all the nice ZFS tools ported/GPLed? or just the cli ones?

What can ZFS do for you that you can't do with other systems?

Seriously - as a home user, what do you need?

Snapshots are cool - essential if you need to backup a 24x7 operation. Now weigh up the complexity vs the risk they introduce.
_________________________
LittleBlueThing Running twin 30's

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#297864 - 04/05/2007 10:57 Re: ultimate home RAID gizmo (random pondering) [Re: LittleBlueThing]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14484
Loc: Canada
Quote:

Snapshots are cool - essential if you need to backup a 24x7 operation. Now weigh up the complexity vs the risk they introduce.


Yeah. Linux also has snapshots, and they work on *any* filesystem type, including ext2, ext3, xfs, FAT, ...

But I haven't yet seen a simple GUI widget to make them easy to use, and the CLI tool just plain sucks for complexity. And the "can I recover" from disaster question nags me whenever I'm adding layers to the software between me and my files!

Cheers

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#297865 - 04/05/2007 13:00 Re: ultimate home RAID gizmo (random pondering) [Re: mlord]
DWallach
carpal tunnel

Registered: 30/04/2000
Posts: 3810
Years ago, we had a NetApp filer, and its daily snapshots were easy to use and were worth their weight in gold when you had the occasional software disaster (e.g., Netscape once crashed on me, leaving behind garbage in its config files). Just cd yesterday and copy the files back to today. The Infrant box, built on Linux and using its snapshot feature, gets part way there, but it's not nearly as easy to get to the snapshots. ZFS, if it lives up to its marketing, lets you make a snapshot any time you want with very low overhead and a simple naming convention that seems suspiciously like the way NetApp does it. ZFS's RAID support and end-to-end integrity checks are also very impressive. ZFS's send and receive features appear to make it almost painless to synchronize your filesystem with a remote server.

All very impressive stuff, but it's a valid question to ask what degree of tools support you'll get standing behind it if/when something goes wrong.

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#297866 - 04/05/2007 13:16 Re: ultimate home RAID gizmo (random pondering) [Re: mlord]
LittleBlueThing
addict

Registered: 11/01/2002
Posts: 612
Loc: Reading, UK
Quote:
Quote:

Snapshots are cool - essential if you need to backup a 24x7 operation. Now weigh up the complexity vs the risk they introduce.


Yeah. Linux also has snapshots, and they work on *any* filesystem type, including ext2, ext3, xfs, FAT, ...

But I haven't yet seen a simple GUI widget to make them easy to use

Have you seen EVMS? Or is that why you said "simple"?

Quote:
And the "can I recover" from disaster question nags me whenever I'm adding layers to the software between me and my files!

<grin> the number of times I've done a disk swap on a raid, started the rebuild and, when mounting to verify all is well, gotten the 'no filesystem' type response because I forgot the lvm layer!!!
What's annoying is that it gives me a new grey hair *every time*.
_________________________
LittleBlueThing Running twin 30's

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#297867 - 04/05/2007 13:32 Re: ultimate home RAID gizmo (random pondering) [Re: LittleBlueThing]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14484
Loc: Canada
Quote:
Quote:

But I haven't yet seen a simple GUI widget to make them easy to use

Have you seen EVMS? Or is that why you said "simple"?


Yeah, EVMS fails the "simple" test. Way too many steps/screens to do a snapshot. They could learn a lot from the VMware Workstation "snapshot tree" tool.

Cheers

(edit: one of the quotes was unclosed)


Edited by Roger (04/05/2007 14:28)

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