How can I keep the /home partition untouched using archinstall?

augur · Yesterday 15:51:51

I'm doing this on a virtual machine. I'd rather not learn the process by experimenting on bare metal (although I backed up my entire system and, separately, my /home partition).

I have 4 partitions: boot, root, swap and home. I want to find out what the proper way is to have the first three wiped and /home untouched.

Manual disk partitioning in archinstall offers marking/unmarking partitions for formatting, which wipes data. When I select that option in the menu, I can't determine the way the partition has been marked. When I enter the menu again, the marking/unmarking option is gone. Wipe: False is set for the entire drive.

I found the wipe option in fdisk, but does it delete the data, too?

The manual:

-w, --wipe when
Wipe filesystem, RAID and partition-table signatures from the
device, in order to avoid possible collisions. The argument
when can be auto, never or always. When this option is not
given, the default is auto, in which case signatures are wiped
only when in interactive mode. In all cases detected
signatures are reported by warning messages before a new
partition table is created. See also wipefs(8) command.

Another manual:

wipefs can erase filesystem, raid or partition-table signatures
(magic strings) from the specified device to make the signatures
invisible for libblkid. wipefs does not erase the filesystem
itself nor any other data from the device.

I can't find this option in cfdisk.

Should I delete the partitions I want wiped using fdisk and create new ones?

Last edited by augur (Yesterday 15:56:08)

mpan · Yesterday 18:20:17

Welcome to the forum.

The question mixes multiple separate issues. Below is each of them answered separately. But you may also skip that part and get a more direct solution, if you explain what you mean by “wipe.” Not what you want to do with archinstall, but what is the end result you want to achieve. Preferably don’t use word “wipe” and don’t try to replace it with any other word in the same meaning: use a description.

The answers:
The Guided Installer script in Archinstall isn’t a comprehensive tool. Archinstall itself isn’t an installer in the first place. It’s a framework which users may use to write their own automatic or semi-automated Arch deployments. One such example profile comes preinstalled: The Guided Installer. It should by no means be taken as a way to skip understanding the normal installation process. It’s an aid to people already knowing that and needing a quick deployment in some typical scenarios, not a substitute. So don’t expect it can do a lot beyond the basics.

The wipe option in the Guided Installer script applies to the entire device. I don’t recall the exact semantics now, and they are not specified, but skimming over the source it seems it just overwrites area with the partition table. It damages data, but does not completely erase it.

wipefs removes signatures of filesystems etc. It overwrites short byte sequences (e.g. magic numbers) that make the kernel and other utilities recognize filesystems. But that’s all. Neither the metadata nor data is touched. The operation is reversible, if backups are made.

Data erasure has multiple meanings, depending on what is the goal and, if it’s for security purposes, what is the threat model. Deletion of data for security purposes requires at minimum a full-disk erase operation (for unencrypted volumes) or proper discarding of the key (for encrypted volumes).

To just repartition, without actually destroying data, no wiping is needed. Just delete all old partitions except the one to be saved, create new ones. Bytes from old data will not interfere with that in any way.

For all big operations on storage media, important data should always be backed up. It’s the kind of thing where we’re a finger slip from a catastrophe, regardless of how good plan we have. Humans make mistakes. Some operations put enough stress on the device that they may trigger a malfunction. Backup, backup, backup.

Last edited by mpan (Yesterday 18:29:46)

WorMzy · Yesterday 18:31:15

Mod note: moving to archinstall subforum.

MAYBL8 · Yesterday 18:31:45

The easiest way is to make the /boot partition and / (root) partition. Format the / partition. make it around 40gb depending on the size of your disk. Select /home for the rest of the drive but select to not format it. That should do it. also select swap if you want one. That it the ruff overview of what to do

Arch Linux

#1 Yesterday 15:51:51

How can I keep the /home partition untouched using archinstall?

#2 Yesterday 18:20:17

Re: How can I keep the /home partition untouched using archinstall?

#3 Yesterday 18:31:15

Re: How can I keep the /home partition untouched using archinstall?

#4 Yesterday 18:31:45

Re: How can I keep the /home partition untouched using archinstall?

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