Upgrades: LVM to SSD migration

ExecutorElassus · Posted: Tue Oct 11, 2016 2:26 pm Post subject: Upgrades: LVM to SSD migration

I have a rather substantial hardware upgrade on its way, and I'd like some advice on how to manage it without drinking myself into a coma or setting myself or my computer on fire. To wit, I'm replacing the mobo/CPU/RAM on my system, but also -- more significantly -- adding three SSDs to get a performance and boot-time improvement. My present hard-drive setup is somewhat complex, so I'd like some advice as to how best to manage the transition.

Here's what I have presently:
Three HDs are partitioned exactly the same: 100MB for /boot (RAID1/mirrored across all three), 10GB for / (also RAID1), 2GB for <swap> (three independent partitions), and all the rest of the drive part of one big RAID6 array. This RAID6 array is further partitioned to contain the following LVM partitions:

/portage
/portage/distfiles
/usr
/var
/var/tmp/
/opt
/home
and nine partitions as storage partitions varying in size from 100GB to 1.5TB

When finished with the transition, I want the following:
/boot, /, <swap>, /portage, /portage/distfiles, /usr, /var, /var/tmp, and /opt (as well as all other system partitions) all on two of the SSDs, mirrored as a RAID1 array.
/home and all the storage partitions (save one) and its subdirectories expanded to fill the entire three HDs, which will now be a single partition in a RAID6 array
that one storage subdirectory on the last SSD

I have a total of 6 SATA ports on the new mobo, so I could conceivably have all six drives attached at the same time. How, then, do I go about migrating from one setup to the other? Is my proposed target the best solution, or is there a better way to use the (upgraded) hardware that I'll have? What is the best way to copy an entire partition's contents, preserving file attributes like access/modification time, etc.?

Thanks in advance for the help. Huzzah for pimped-out machines!

Cheers,

EE
ADDED: furthermore, if at all possible, I would like to encrypt the system as much as possible while I'm transitioning over. At least /, and possibly also the /home partitions, I would like to have protected with encryption, meaning that I'll have to wipe the partitions (probably one at a time) as I remove them from and re-add them to the arrays.
ADDED 2: furthermore, as /var and /usr are on an LVM, I presently boot using an initrd (kindly shepherded into functioning by Neddy Seagoon) to pre-mount and scan them before transitioning to "real" root. Since this will no longer be necessary, how do I transition back to *not* using the initrd to boot?

frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

ExecutorElassus · Posted: Tue Oct 11, 2016 9:18 pm Post subject:

Roman_Gruber · Posted: Wed Oct 12, 2016 5:44 am Post subject:

I have not read the full post.

I have three SSDs which I switch as backup or system drives. 120GB SSDs or 128GB SSDs. 2 Drives on the shelf, one in use. Its a rotation cycle, the backup drive is than mounted in my notebook and the system drive is than put on the shelf.

I have hte distfiles on an ordinary HDD.

Boot is unencrypted as the handbook wants it with 128MB on the SSD
root is LVM / LUKS on the SSD. Last backup revealed that i moved 32GB of data for root.
Some older User data resides on the 1TB 2.5" HDD, becuase its hardly used and I am too lazy to sort it out. Its not backuped because its very old, not that important

Disk Wise: 128GB / 120GB SSD is enough for root including home without the distfiles for a desctop user with a minimalistic desctop like i3wm + custom scripts.