luks, zfs, /var

Message

deathraccoon · Post by **deathraccoon** » Thu Dec 17, 2015 7:53 pm

I m reinstalling Gentoo. I have two drives, a primary SSD which holds the system. This is formatted with XFS and Ext4. My secondary, data, drive is encrypted with LUKS and uses a ZFS filesystem.

I want to mount a dataset from the encrypted (secondary) drive onto /var in the primary drive in order to use compression and take the load off the SSD.

My question: during the boot process, will /var need to be available to the system *before* decryption of the secondary drive occurs and the zpool is imported, or can I boot into the system without /var?

Roman_Gruber · Post by **Roman_Gruber** » Thu Dec 17, 2015 8:25 pm

In short, you need an initramfs.

Personal opinion.

encrypt the hole box or leave it. (too much to go into details, the internet is full why, temp files, .. configs, lint ... not good to only encrypt a subset)

i used for years encryption on t9500 cpu (thats 7+ years old now)
past 2-3 years ssd with encryption

now a new box. disc wise there is not much difference

t9500 wiht encryption vs t4300 without encryption (two gentoo notebooks)

i have

25 gb used for everything for / (on a 120gb adata ssd)
*) /usr/portage does not have to be on the ssd
*) /var/log ... same
*) with Downloand folder which will be soon a temporary folder(5gb)

1tb drive for distfiles, and a few junk files from the past which i do not care

I am quite sure i can slim down my hole gentoo box to 20gb, which is easy to backup in a few minutes via usb-3.0 and a ssd in it.

cheapest sata ssd will do the job becaue you use encryption.

deathraccoon · Post by **deathraccoon** » Thu Dec 17, 2015 9:29 pm

I know what I must do now. Simply create a new zpool at /var. I was thinking in terms of needing to use the one zpool at the encrypted drive, but there's no reason I can't make another.

likewhoa · Post by **likewhoa** » Fri Dec 18, 2015 3:25 pm

You won't need /var mounted for ZFS or the system to boot and ZFS should mount your dataset once the system switches to the real root. So no initramfs needed unless you encrypt /.