- main - earth.li

How to remove password having got root access to a system?
by Chris Green 17 Dec '11

17 Dec '11

Well, after a fair amount of hassle, I've worked out how to get root access to the hard disk on the system I have installed xubuntu 11.10 but the main account password is broken. You boot the "Live CD" system and you can then mount the disk and use sudo to become root. So, I can edit /etc/passwd and I can edit /etc/shadow but removing the password field from my main/default user in the /etc/shadow file *still* doesn't allow me to login. Grrrrr!!! What are the requisites for a login to have no password? I thought it was a 'x' in the password field in /etc/passwd and nothing in the password field in /etc/shadow but that seems not to work. -- Chris Green

3 3

Can't get Grub menu to appear, nor the boot sequence text
by Chris Green 17 Dec '11

17 Dec '11

Sort of going on from investigating my boot times I've just realised I seem to be unable to see/start the grub menu on my system. All I see is the BIOS boot sequence, finishing with the SATA drives being detected, then there is a blank screen (though the monitor indicates it is being driven) for several seconds followed finally by the login screen. I have just changed /etc/default/grub to:- GRUB_DEFAULT=0 GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT= GRUB_CMDLINE_LINUX="" ... and I still see absolutely nothing between BIOS and login screen. Any ideas as to what I can do to see the grub screen? Apart from anything else if I have some sort of catastrophe it's going to be a bit difficult to get into single user/command line mode. -- Chris Green

5 8

PCI SATA Card
by steve-ALUG＠hst.me.uk 17 Dec '11

17 Dec '11

Why is nothing ever simple? Replacement Sata disks sourced, purchased, plugged 1 in. Spins up, but not detected. Turns out my Motherboard has a SATA 1 controller chip that will not work under any circumstances with SATA 2 disks, even if you tell the disks to pretend to be SATA 1 disks. Don't suppose anyone has a linux compatable PCI SATA controller card with 2 Sata channels lying around that they don't need do they? (Note, that's PCI, not PCI-X, or PCI Express). What a waste of an evening! Harumph!!! Steve

1 0

Have I got a disk failing - or what?
by Chris Green 14 Dec '11

14 Dec '11

My logwatch presented me with this (among other things) this morning:- --------------------- Kernel Begin ------------------------ WARNING: Kernel Errors Present [ 7.192693] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro ...: 1 Time(s) [ 7.386581] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro ...: 1 Time(s) [ 20.697614] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro ...: 1 Time(s) [ 20.824819] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro ...: 1 Time(s) [ 20.861868] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro ...: 1 Time(s) [ 20.907760] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro ...: 1 Time(s) [ 20.945476] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro ...: 1 Time(s) [ 21.031194] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro ...: 1 Time(s) [ 27.012635] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,comm ...: 1 Time(s) [ 28.113740] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,comm ...: 1 Time(s) [ 28.463488] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,comm ...: 1 Time(s) [ 33.145286] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,comm ...: 1 Time(s) [ 33.649576] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,comm ...: 1 Time(s) [ 34.486168] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,comm ...: 1 Time(s) [ 45.508896] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,comm ...: 1 Time(s) [ 49.252032] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,comm ...: 1 Time(s) ---------------------- Kernel End ------------------------- Should I be worried? That's my 'root' disk:- /dev/sda1 on / type ext4 (rw,errors=remount-ro,commit=0) It doesn't have either /home or /bak on it so it's just system configuration that needs to be preserved (which it is). -- Chris Green

2 4

Replacing RAID Disks
by steve-ALUG＠hst.me.uk 13 Dec '11

13 Dec '11

Hi Guys & Gals, I have a server running Ubuntu Lucid 10.04. It has 2 sata disks running as RAID level 1 (simple mirror) using MDADM. Recently there's been an error on 1 of the disks. After a reboot, the raid array resynchronised itself, but I'm taking this as a warning and an excuse to replace the disks. I have several questions. First of which is, is MDADM still the way to go? I seem to remember reading that you can set up RAID 1 with just using ext4. Presumably MADAM is still the best. Next, my original partitioning scheme was one / (root) raid device with partition, and one swap raid device swap with partition. I presume that a better layout would be to have / (root), home and swap raid devices with partitions. Should I be using LVM as well, or just shove a partition directly on the raid device? I don't want to do a fresh install, I want to copy the data over from the old disk to the new ones. What's the best way of going about this? I can only have 2 drives connected at a time, but I could put the new disks into a spare computer and transfer files over the network if necessary. I'm hoping that I may be able to get away with this: Using the appropriate raid controls, remove the "faulty" drive from the raid array, then physically remove it. Then physically mount one new, bigger drive. Create 3 raid partitions on the and format one as / (root) and one as swap, leaving the other one empty for a bit. Using the appropriate raid controls, mount the new devices and let them synch. Unmount and remove the remaining old drive. Mount, partition then add the new drive to the raid. Let it synch. Once that's all happened, boot from a live cd, mount the devices, format the spare partition as "home", copy (move) files from the home directory to the new home partition. Would this work? Or is there a better way? Any comments appreciated. Steve

3 3

Where is all the time going?
by Chris Green 13 Dec '11

13 Dec '11

Feeling a bit bored (and waiting for some replies to questions elsewhere) I decided to look and see where all my boot time is going. There are two very obvious pauses in the dmesg output:- [ 2.934091] ata8: SATA link down (SStatus 0 SControl 300) [ 2.934130] ata7: SATA link down (SStatus 0 SControl 300) [ 18.251024] Adding 9936892k swap on /dev/sda5. Priority:-1 extents:1 across:9936892k [ 20.088037] <30>udev[292]: starting version 167 [ 20.133565] lp: driver loaded but no devices found ... ... ... [ 23.959982] FS-Cache: Loaded [ 24.133173] FS-Cache: Netfs 'nfs' registered for caching [ 24.143427] Installing knfsd (copyright (C) 1996 okir(a)monad.swb.de) [ 24.353496] type=1400 audit(1323793685.691:10): apparmor="STATUS" operation="profile_replace" na> [ 24.353957] type=1400 audit(1323793685.691:11): apparmor="STATUS" operation="profile_load" name=> [ 34.486168] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,commit=0 [ 36.986993] svc: failed to register lockdv1 RPC service (errno 97). [ 36.987111] NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory [ 36.996319] NFSD: starting 90-second grace period ... ... ... [ 38.612346] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 49.294292] eth0: no IPv6 routers present I don't think that last gap waiting for IPv6 routers is relevant, I can do just about anything before that happens. So, any ideas what may be causing that first 16 second gap and/or the second ten second gap? -- Chris Green

3 4

X over ssh problem
by mick 12 Dec '11

12 Dec '11

Hi guys I use ssh tunneling to manage my remote systems, but until today I have never attempted to forward X over a tunnel (I don't have X servers running remotely and I have never seen the need to run X based graphical programs on those servers). Today I wanted to run etherape on a remote server so that I could watch the traffic patterns. So. I changed the remote server's sshd_config to enable X forwarding ("X11Forwarding no" becomes "X11Forwarding yes") and restarted sshd. On my desktop I similarly changed my local ssh_config file to allow X forwarding ("ForwardX11 no" becomes "ForwardX11 yes") to obviate the need to use the -X switch on the command line. I then installed etherape on the remote server and fired it up only to get the message "Error: no display specified". Sure enough "echo $DISPLAY" shows nothing. But I thought (and everything I have read confirms) that ssh should take care of setting the appropriate display when X11 forwarding is set. I then tried setting a display manually (export DISPLAY=localhost:10.0 on the remote server) and got the response "Error: cannot open display: localhost:10.0" I must be missing something. What am I doing wrong and how can I fix it? Surely I don't have to have an X server running on the remote host? Thanks in advance. Mick

2 3

Set up Raw Printer with CUPS (Debian+Gnome)
by ted.harding＠wlandres.net 11 Dec '11

11 Dec '11

Greetings all! I am in one of my occasional struggles with CUPS (which I hate -- as compared with good old LPD)! Not helped by the unhelpful Gnome: Desktop --> Administration --> Printing "assistant". Basically, I have an HP LaserJet 1300 which I want to use as a raw printer (I do all my printing via PostScript files which I create myself, and the HP has built-in PS capability, so it's just a matter of piping the PS file straight into the printer, with no intermediate processing). The printer is to be connected to a laptop via a USB cable. So all I want to do is set up printing on the laptop so that when I issue a command lpr filename.ps the PS file gets printed by being sent straight to the printer over the USB port. So how do I set this up as a raw printer? There seems to be no route to this (that I can detect) via the above "assistant". Maybe there is a direct method using CUPS-oriented commands from the command-line, but I can't manage to suss that out either! Any help (especially from people who have done this successfully for themselves) will be highly appreciated! Thanks, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <ted.harding(a)wlandres.net> Fax-to-email: +44 (0)870 094 0861 Date: 08-Dec-11 Time: 19:52:40 ------------------------------ XFMail ------------------------------

2 2

How to test if a cat5 (or cat6) is working as well as it should?
by Chris Green 06 Dec '11

06 Dec '11

I have a number of quite long (i.e. 30 metres or more) cat5e cables strung about the place and would like to test how 'clean' they are. It's easy enough to test their basic integrity (i.e. if all 8 wires are correctly connected) and I have done that. However I'd like to see if they are actually good enough to provide maximum performance when running gigabit. Presumably if they aren't working too well one will see errors and retries at the hardware level - is there a tool for monitoring this? Mostly these cables have just one switch between the ends but there are a couple where there may be two switches involved. -- Chris Green

7 12

Problems with new[ish] Firefox on Ubuntu 11.04
by Chris Green 06 Dec '11

06 Dec '11

I have just upgraded my system to xubuntu 11.04 and I have a couple of problems with the version of Firefox it has installed. The first problem is that I can't even see what version of Firefox it is as the main menus have disappeared (that's the File, Tools and other menus, including the Help menu which tells you which version of Firefox you have). How on earth do I get those menus back? Secondly the new Tab layout is a pain, I've turned off 'Tabs on top' but the tabs are still in a sill place because the leftmost tab sits above the sidebar, not above the web display area. Is there any way to get back to the old layout where the tabs are actually above the pages they refer to? -- Chris Green

3 4