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Having become disillusioned with hacking Buffalo NAS devices, I've decided to roll my own Home server. After some research, I have settled on an HP Proliant Microserver with Ubuntu Server and ZFS (OS on 1 Ext4 disk, Data on 3 RAIDZ disks).

As Joel Spolsky and Geoff Atwood say with regards to backup, I can't rest until I have done a restore in all of the failure scenarios that I am seeking to protect against.

Q: How to configure Ubuntu Server to recognise a pre-existing RAIDZ array?

Clearly if one of the data disks die - then that is a resilvering scenario, which is well documented. If two of the data disks die, then I am into regular backup/restore land. If the OS dies and I can restore, also an easy scenario.

But if the OS dies and I can't restore, then I need to recreate an Ubuntu server. But how do I get this to recognise my RAID-Z array? Is the necessary configuration information stored within and across the RAIZ array and simply need to be found (if so, how)? Or does it reside on the OS ext4 disk (in which case how do I recreate it)?

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up vote 6 down vote accepted

Found my answer at

# zpool import

Implication is that config data must be stored in and across RAIDZ devices.

Apparently, if the data is complete, the import results in ONLINE (e.g. in my case, 3 of my 3 RAIDZ disks), if the data is partially but sufficiently complete the result is DEGRADED (e.g. 2/3); and if the data is insufficiently complete the result is FAULTED (e.g. 1/3).

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