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Re: BTRFS and debian




On 07/09/18 11:17, Ge wrote:
Hi there!
I am new here.

Welcome! :-)


I am trying to install debian on a VM to test it before i install it on
my laptop.

What hardware?  What host OS?  What hypervisor?


Since its a laptop i would like to encrypt the hard drive.

Disk encryption is a discussion unto itself. One choice is a laptop with firmware that supports self-encrypting drives (SED) and a matching HDD/SSD. One software choice for Stretch is dm-crypt/LUKS.

I
would also like to be able to return my whole system to a previous state
or just my home directory.

Backup/recover, imaging, snapshots, version control, etc., are yet more discussions. Since the subject line includes btrfs, subvolumes and snapshots may be an option:

https://en.wikipedia.org/wiki/Btrfs#Subvolumes_and_snapshots


I would need to work through the various use-cases to figure out what can be done with the subvolume mounted and in use, with the subvolume mounted but not in use, and with the subvolume not mounted. (I use dd(1) to image partitions, with the LUKS container closed and/or the file system not mounted.)


I would like to ask

1. Whats the appropriate layout?
My current layout is:

LVM VG Laptop-vg LV root 16.9GB Linux device mapper (linear)
#1	16.9GB	f	btrfs	/


LVM VG Laptop-vg LV swap 4.3GB Linux device mapper (linear)
#1	4.3GB	f	swap	swap

Encrypted volume (sda5_crypt)-21.2GB Linux device mapper (crypt)
#1	21.2GB	K	lvm

SCSI1 (0,0,0) (sda) 21.2GB ATA QEMU HARDDISK
#1	primary	254.8MB	K	ext2	/boot
#5	logical	21.2GB	K	crypto	(sda5_crypt)

I use 16 GiB SSD's and/or 16 GiB USB flash drives for system drives. I wipe and test them using the manufacturer's diagnostic tool before installing Debian, or just wipe them with dd(1) if I do not have a tool. In the Debian Installer, I choose 'manual' for 'partitioning method', create a new partition table (MBR), and create three primary partitions:

1   ~1 GiB btrfs mounted at /boot
2   ~2 GiB LUKS (random key) with swap
3  ~10 GiB LUKS (passphrase) with btrfs mounted at /

10 GiB root is enough for single-user Xfce workstation (my bulk data is on a file server).

The last ~3 GiB are unallocated -- for over-provisioning, because the drives have different numbers of sectors, and because of the GB/ GiB stupidity.


Should i make a different partition for /home/ ?

I don't -- I put my bulk data on a file server, including all e-mail attachments. My home directory is ~1 GB.


(If/when I want to travel with my laptop, I will need to figure out how to set up a VPN to my file server.)


2.I will obviously make the / partition btrfs. Do i have to use btrfs
also on my boot partition?

No, but I do.


3.Is there any btrfs GUI program to manage my system on debian stretch
or on debian buster? or i can only do this from the command line?

STFW I see:

http://carfax.org.uk/btrfs-gui
http://snapper.io/


Stretch has a package for Snapper:

https://packages.debian.org/search?keywords=snapper&searchon=names&suite=stable&section=all


(I use the included command-line tools.)


David