Drive labelling with ZFS
frank2 at fjl.co.uk
Wed Jun 14 08:06:01 UTC 2017
On 14/06/2017 03:02, David Christensen wrote:
> On 06/13/2017 04:32 PM, David Christensen wrote:
>> Both  and  discuss the fact that a given drive, partition, file
>> system, etc., can be identified in various ways, manual or automatic,
>> but the kernel will pick one and "wither" the rest. Once a GPT label is
>> set manually, other methods should be disabled via settings in
>> /boot/loader.conf and the system rebooted ( p. 35):
> Beware that all your disks need to have GPT labels, and those labels
> need to be carried forward into /etc/fstab, etc., before you reboot,
> as the kernel won't be able to find the disks using Disk ID or GPT
> GUID labels once those methods are disabled.
Thanks David. I'd actually tried all the things you suggested, and read
and re-read the Lucas books which blithely suggest setting GEOM labels
but without going in to detail. The first chapter is all over the place
in structure. However, I didn't try the sysctrl tweaks you suggest to
disable the other methods. I recall the books suggesting that other
methods are disabled, but without telling you how.
You may well have supplied the missing piece of the jigsaw here. It's a
shame ZFS can't be told which labelling method to use (or can it?)
Current situation is less than helpful.
The new SAS enclosure utility in 11.0 is great. It can flash the light
on any drive you like, but it only takes device names, not GUIDs. And if
ZFS fails /dev/da87p3 it immediately changes to referring to it by the
GUID only. I can see why assuming the drive is completely off-line but
in most cases it's JUST failed, and therefore knowing where it was is
the same as knowing where it is.
Part of the problem is that zpools created by sysinstall during
installation are on unlabelled partitions. Actually it does label them,
but not in any helpful way. </rant>
More information about the freebsd-questions