Category: PC Tweakage

Up to this point I’ve been using a hardcoded

Option "Rotate" "CCW"

in my /etc/X11/xorg.conf file to get a portrait-mode display on my right-hand monitor, as described in grisly detail there.

That kills xrandr, which prevented any further display configuration and seemed to sometimes kill off the screensaver. Maybe the screens would blank and then power down, maybe they’d just power down, maybe they’d be on all the time.

However, simply eliminating the hardcoded Rotate didn’t solve the problem, as xrandr refused to do anything. The appropriate command-line syntax isn’t obvious to the casual observer, but this was alleged to work: xrandr -o left.

Come to find out, after considerable digging, that one must add this secret incantation to each Display stanza in /etc/X11/xorg.conf:

Option  "RandRRotation" "on"

And, perforce, remove the Rotate option.

That’s evidently due to the fact I’m using the proprietary nVidia driver, which I think everybody does.

Log out, Ctrl-Alt-Backspace to restart the X server, log back in again, and shazam the cute little Display applet in the Settings Manager actually works. Not only that, but you can specify Left rotation for Display 1 and that actually works, too.

Update: but, alas, it seems to not be sticky between sessions. Worse, there seems to be no combination of xrandr parameters that can rotate the right-hand screen from a console on the other or, presumably, from a startup script. It is not obvious what this means, either:

This option selects the X display to use. Note this refers to the X screen abstraction, not the monitor (or output).

I can’t find anything that works.

And, FWIW, there’s no Screensaver config applet in the Settings Manager (at least not that I can find), so you fire it up from the command line:

gnome-screensaver-preferences

Yes, you use the Gnome screensaver preferences in Xubuntu.

We need Samba for the Token Windows Laptop and the CNC box on the milling machine which also runs TurboTax during that season of the year. Despite having done this many times before, it never works right until, suddenly, without warning, everything works. It’s a permission thing, I think.

To get SWAT running, check there, which boils down to:

• sudo chmod g+w /etc/samba/smb.conf
• sudo chgrp adm /etc/samba/smb.conf

Put this in /etc/xinetd.d/swat:

... comments snipped ...
service swat
{
        port    = 901
        socket_type     = stream
        wait    = no
###     only_from = localhost
        user    = <<your adm-enabled userid>>
        server  = /usr/sbin/swat
        log_on_failure  += USERID
        disable = no
}

Then use sudo smbpasswd -a -e <> to set up the allowed users and get their passwords aligned. I use the same userids and paswords on all the boxes, which is terrible security.

Whenever you change anything, use sudo /etc/init.d/samba restart to make sure Samba gets the message.

Use SWAT to set up all the shares. This is what the config file looked like after the damn thing finally started working:

# Samba config file created using SWAT
... snippage ...

[global]
	workgroup = whatever-you-use
	server string = %h server (Samba, Ubuntu)
	map to guest = Bad User
	obey pam restrictions = Yes
	passdb backend = tdbsam
	pam password change = Yes
	passwd program = /usr/bin/passwd %u
	passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
	unix password sync = Yes
	syslog = 0
	log file = /var/log/samba/log.%m
	max log size = 1000
	dns proxy = No
	usershare allow guests = No
	panic action = /usr/share/samba/panic-action %d

[printers]
	comment = All Printers
	path = /var/spool/samba
	create mask = 0700
	browseable = Yes
	printable = Yes
	writeable = Yes

[print$]
	comment = Printer Drivers
	path = /var/lib/samba/printers

[Bulkdata]
	comment = Assorted useful files
	path = /mnt/bulkdata
	read only = No

... likewise for other file shares ...

Actually, you don’t have to share the printers with Samba. Better to use CUPs directly. Just tell Windows to “Connect to a printer on the Internet or on a home or office network”, then fill in something like:

http://oyster:631/printers/R380_TP

And that’ll work even better.

Having just bumped the basement file server from Kubuntu 7.10 to Xubuntu 8.10, a few notes are in order…

The general idea was to saw an existing 20 GB partition in half, maintain the existing 7.10 installation, and install 8.10 in the liberated part. The overview:

• partimage — back up the 7.10 installation in sda6 and the data in sda7
• resize2fs -p /dev/sda6 5G — squish the filesystem down
• partimage — save the squished filesystem
• cfdisk — delete sda6 and create a pair of 10 GB partitions sda6 and sda7
• partimage — restore the squished filesystem to sda6
• e2fsck -fv /dev/sda6 — prep it for resizing
• resize2fs -p /dev/sda6 — expand to fill entire partition
• tweak /etc/fstab to reflect the fact that sda7 has become sda8
• reboot and shazam 7.10 started up just fine

Then install 8.10 in sda7 and configure from there, using the 7.10 installation as a reference to help remember what’s needed.

The only complication was that the Ubuntu 8.10 mini-ISO install enumerated the USB backup drive as sda, so things got a bit weird; evidently, the USB drive now has the grub MBR. Unplugging that drive, then deploying a bit of grub fu from SystemRescueCD fixed that up:

• find /boot/grub/stage1 — appears in (hd0,5) and (hd0,6), thus sda6 & sda7
• root (hd0,6)
• setup (hd0)
  

Then apply the relevant installation info from the series starting there, omitting all the user apps and foo-foos that won’t be needed on the basement box.

Add useful server programs:

• nfs-kernel-server
• xinetd
• swat

There’s an authorization bug that may kill local login and sudo, as documented there, triggered when you configure CUPS printers (among other causes). The quick-and-dirty solution seems to be:

• boot in recovery mode
• remove samba*
• install samba
• install xubuntu-desktop

It’s worth noting that I’d just finished configuring ssh for public-key logins, so I could get into the box from my Comfy Chair upstairs, but I couldn’t reconfigure anything because sudo segfaulted.

Create mountpoints, then set up /etc/fstab to automount the various partitions:

/dev/sda8 /mnt/music		ext3	defaults,noatime,auto,rw,nodev,noexec,nosuid 0 0
/dev/sdb1 /mnt/bulkdata		ext3	defaults,noatime,auto,rw,nodev,noexec,nosuid 0 0
/dev/sdb2 /mnt/diskimages	ext3	defaults,noatime,auto,rw,nodev,noexec,nosuid 0 0
/dev/sdb3 /mnt/userfiles	ext3	defaults,noatime,auto,rw,nodev,noexec,nosuid 0 0
UUID=069e50dc-1994-47d2-9c7e-0b5179a89041 /mnt/backup ext2 defaults,noatime,noauto,nodev,noexec,nosuid 0 0

It would be more sensible to use UUIDs for those partitions, but that stuff hasn’t broken yet. If the USB backup drive enumerates as sda again, then I’ll be forced to tweak it.

Add stanzas like this to /etc/exports:

/mnt/bulkdata *(rw,async,subtree_check,root_squash,no_all_squash)

That gets the files served to the other boxes.

Install Turboprint and tweak the printer drivers accordingly.