[CentOS] Migrating to nvme and expand

Fri Apr 2 07:37:31 UTC 2021
Roberto Ragusa <mail at robertoragusa.it>

On 4/1/21 12:22 AM, Jerry Geis wrote:
>> Are you using the MD devices as Physical Volumes ?If ues, then create a
> PV from that NVME and then pvmove.
>> Best Regards,Strahil Nikolov
> more /proc/mdstat
> Personalities : [raid1]
> md126 : active raid1 sdb3[2] sda3[0]
>        1866465280 blocks super 1.2 [2/2] [UU]
>        bitmap: 4/14 pages [16KB], 65536KB chunk
> md127 : active raid1 sdb1[0] sda1[2]
>        52461440 blocks super 1.0 [2/2] [UU]
>        bitmap: 1/1 pages [4KB], 65536KB chunk
So you are not using LVM and everything gets more complicated.

For sure, you have to do the movement while booting from a rescue disk.
Either you use some partition cloning/rearrangement tool (assuming
they are able to cope with a RAID1 source) or you simply create
new filesystems, format them and copy all the files over.
I would go for the second option, and really use LVM on the NVMe
and not assign all the space to /home because that is almost irreversible
while gradual expansion is very easy to do later.
Then, adjusting grub to use the NMVe is also necessary.
And, of course, checking which drive the BIOS is set to boot from.

This is all easily doable for experienced users, but in each step
there is a chance to make bad errors.

    Roberto Ragusa    mail at robertoragusa.it