Re: [gentoo-user] Fun with mdadm (Software RAID)

[Steven Lembark <lembark@wrkhors.com>]

> I think any system admins reading this would long for the
> predictability of "consumer hardware", having too often been
> confronted with indistinguishable 32 hex digit identifiers.  I would
> imagine it quite likely that the said admins have written scripts to
> make this more manageable.

Simple fix: use LVM, let it deal with the UUID. At that point
the PV's get UUID's, the VG's get UUID's, the LV's get UUID's
and you never have to type or see or use them.

Snippet from my /etc/fstab:

    /dev/vg00/root      /           xfs ...
    /dev/vg00/var       /var        xfs ...
    /dev/vg00/var-tmp   /var/tmp    xfs ...

this is basically the same fstab on my server & notebook, hasn't
changed in the transitions from ATA to SATA to SCSI to SAS to 
NVME. 

If you want mirroring then either create a mirror with mdadm 
and use it as a PV -- kenel will auto-start the mirror, vgscan
will find it, and Viola!, it's up -- or use -m2 and mirror/stripe/
RAID5/whatever using lvcreate to spread the data across whatever
you like. 

Here I have two nvme's (used to be scsi, then sas) which are mirrored
for vg00 w/ the root, var, home filesystems another that's striped
for /var/tmp and other scratch spaces.

This gives an overview:

https://speakerdeck.com/lembark/its-only-logical-lvm-for-linux

-- 
Steven Lembark
Workhorse Computing
lembark@wrkhors.com
+1 888 359 3508