been running for a couple years...crashed today; how to recover data?

[batpot]

Don't know what version I was running, but I had setup a ZFS pool across 4 750gb hard drives, and am using a USB drive for booting.

I was streaming a video from it, and it crashed, and I heard it restart, but never got the beeps indicating it had started up again.

I shut it down, plugged in a monitor/keyboard, and the restart took a long time, but eventually came to an option screen...boot freenas, boot in safe mode, various other options.
Doing nothing resulted in eventually getting a message saying config.xml file is missing; I restarted and tried safe mode, and it seemed to just stop loading at some point.

As near as I can tell, somehow the usb thumb drive got corrupted.

Can I install the newest version w/out re-silvering?

 

[ProtoSD]

If you've been running for a couple of years and streaming video from it, and getting a message about config.xml, you had to be running version .7. You're asking in the wrong forums for .7 questions (Link for FreeNAS 7 is in the titlebar at the top of the page). There shouldn't be any resilvering involved at all, reinstall the version you were using, they are different versions of ZFS.

The FreeNAS™ 8 series represents an entire rewrite from the .7 series of FreeNAS™. In other words, FreeNAS™ was rewritten from scratch and features were added as the new base stabilized. This means that not every feature in the .7 series was re-implemented and some features that are not available in FreeNAS™ .7 are available in FreeNAS™ 8.x. ...

New developers and new code.

 

[batpot]

Ok, yeah, that was kind of a different question that maybe I should have asked: can I (should I) install FreeNAS 8 w/out having to re-silver.

You're suggesting just reinstalling the .7 version instead?

 

[Milhouse]

Note that there is currently no upgrade path for FreeNAS 0.7 to FreeNAS 8, so if you do install FreeNAS 8 you will lose your configuration (even assuming you had a backup) AND also your data. To use FreeNAS 8 you will need to set everything up from scratch, and restore your data from backup, as FreeNAS 8 uses a different version of ZFS (v15, whereas FreeNAS 0.7 uses v13)*.

A FreeNAS 0.7-to-8 upgrade feature is planned for FreeNAS 8.2.

* If you're up to it, you could auto-import the v13 volume in FreeNAS 8 then drop to the CLI and upgrade the pool to v15, which would obviate the need to restore the data from backup, but there's will be no going back once you have done this, so you better be sure you want to use FreeNAS 8 which still lacks some features present in FreeNAS 0.7. If you were happy running FreeNAS 0.7 then my advice would be to stick with what you know works. :)