Gentoo Archives: gentoo-user

From: Philip Webb <purslow@××××××××.net>
To: Gentoo User <gentoo-user@l.g.o>
Subject: [gentoo-user] no /usr , no problem
Date: Sun, 06 May 2012 10:14:53
Message-Id: 20120506101256.GA2966@ca.inter.net
1 Everyone knows about the problem of /usr on a separate partition.
2 My 2003 machine + my netbook have /usr on the same partition as / ,
3 but by regular desktop machine (2007) had /usr on an LVM partition.
4 I plan to build a new machine later in the year
5 & didn't want to have to learn re Initramfs, Drakut etc
6 & be stuck with an odd-ball machine as stand-by for the next so-many years,
7 so I decided to put /usr on the same partition as / .
8 Since / is on /dev/sda3 , which didn't have enough space for both,
9 that meant a major re-organisation of the hard drive.
10 I've now completed that job & am surprised how straightforward it was,
11 so in case anyone else is wondering what to do, here's an outline.
12
13 First of course, be careful & pay attention to what you're doing !
14 It took me 5 days altogether from beginning to end.
15
16 (1) back up everything, incl /boot + / :
17 I bought 48 GB USB sticks to store the system + my personal files ;
18 make sure you 'cp -a' at every stage : the '-a' flag is vital.
19 It's much slower copying to USB than copying back to HDD ;
20 always 'umount' the USB before removing it !
21 -- I have a bad dir on 1 stick as a result of forgetting that.
22
23 (2) check the back-up files, try out System Rescue
24 & test copying to/from USB after booting SR.
25
26 (3) design the new partition layout & the new LVM layout.
27
28 (4) when you're satisfied everything is ready
29 -- part of the reason it takes 5 days is that you need to sleep on it -- ,
30 boot from System Rescue : I used 2.6.0 , which is impressively powerful.
31 I've marked the places where "your mileage my vary".
32
33 Then (a) make a final back-up of constantly changing stuff, in my case
34 ~/Mail /var/log + a special dir in which I kept news items + pictures,
35 which I grab from my daily read of the press (YMMV).
36 (b) use LVM to deactivate + remove LVs, then the VG ( /dev/sda5 : YMMV);
37 (c) use Gparted to resize /dev/sda3 + recreate /dev/sda4 - /dev/sd9 (YMMV);
38 (d) use LVM to recreate the VG + LVs ;
39 (e) use 'resize_reiserfs' (YMMV) to extend the formatting of /dev/sda3
40 & 'mkreiserfs' to format the recreated partitions ;
41 (f) copy /usr from USB to /dev/sda3 ;
42 (g) copy /var /var/log from USB to the new LV (YMMV);
43 (h) copy /home etc ditto : I needed my LV of pictures
44 to get the desktop background, which is stored there (YMMV);
45 (i) install a new /etc/fstab : edit it under a new name before starting SR,
46 then copy it into place at this point, keeping a copy of the old one.
47
48 (5) reboot & copy the rest of your data to the new LVs.
49
50 I was amazed that after doing the above procedure carefully,
51 the system came back & everything is now working normally, incl Portage.
52
53 YMMV, so make sure you design your own procedure to fit your own needs.
54
55 HTH a few users.
56
57 --
58 ========================,,============================================
59 SUPPORT ___________//___, Philip Webb
60 ELECTRIC /] [] [] [] [] []| Cities Centre, University of Toronto
61 TRANSIT `-O----------O---' purslowatchassdotutorontodotca