Re: Lockdown adaX numbers to allow booting ?

On Fri, Sep 20, 2019 at 08:29:08AM -0700, Freddie Cash wrote:

> On Fri, Sep 20, 2019 at 7:35 AM Slawa Olhovchenkov <slw_at_zxy.spb.ru> wrote:
> 
> > On Thu, Sep 19, 2019 at 06:04:54PM +0200, Michael Gmelin wrote:
> > > What about gpart output of the pool drives?
> > >
> > > In general you would create zpools using gptids or gpt labels, not the
> > devices, so you’re independent of device numbering. The boot loader should
> > only be installed on drives that contain the boot pool (maybe you have old
> > boot loaders on data drives?).
> >
> > ZFS work w/ ZFS labels, not w/ device names/gptids/gpt labels.
> > You don't worry about changed device names aroud reboots.
> >
> 
> Very true, from ZFS' point of view.  It writes a ZFS label to whichever
> GEOM provider you hand it (file, iSCSI device, raw device, MBR partition,
> GPT partition, etc), and it will find it's pool members based on those
> labels.  ZFS doesn't care where the device is physically connected in the
> system, just that it is connected.
> 
> But the ZFS labels aren't what it will display in "zpool list -v" or "zpool
> status" output.  That will show the GEOM provider you gave it (and,
> depending on the order that GEOM tastes the devices, and what's
> enabled/disabled in loader.conf, that output can change).  That's where
> it's useful to have human-readable, descriptive labels (like GPT partition
> labels), and to disable all the GEOM ID systems you won't be using via
> loader.conf.  So that when things go sideways, and a disk dies, you can
> find it quickly and easily.  Much easier to replace "gpt/jbod3-a6" in a
> multi-chassis storage system with 100+ drives than to figure out which bay
> corresponds to "ada73" after a couple of reboots that may or may not have
> changed the PCI bus enumeration direction, or after replacing an HBA that

Location of device in multi-chassis storage system is different story.
I am don't know how to field engineer insert disks in chassis.
For me simple is find in /var/run/dmesg.boot S/N <=> daXY mapping and
turn ON led by sas2ircu.

> enumerates drives a different way (da vs ada), or after a BIOS/EFI upgrade
> that renumbers things, or any other number of situations.  (We've run into
> most of these, and have come to rely on GPT partition labels for just this
> reason; and we stick the drive serial number on the outside of the bay,
> just in case).

> It's not a ZFS requirement.  It just makes things easier for the admin down
> the road. Especially if the admin team changes or inherits systems.  :)

This is need many manual work at setup and build time.
DC field engineer make servers for me and don't do this work for me.