isw: Could not find disk /dev/sd# in the metadata error with dmraid

Reinstalled my old rig yesterday, to switch from a RAID0 to a RAID1 conf, now that the bulk of my data is stored in the RAID5 array from my HTPC. As usual, using the Motherboard's fakeraid driver. This time it's the intel's ICH8R Matrix Storage RAID driver (and boy is it slow on rebuilding RAID1 arrays, which I had to do since I only got a brand new Vista64 stable for four hours before a complete freezout that required a hard reset!).

As usual, went through a Linux reinstall, only to find out that dmraid 1.0.0.rc15 would return the following:
root@dusk:/usr/src/dmraid/1.0.0.rc15# dmraid -ay
ERROR: isw: Could not find disk /dev/sdc in the metadata
ERROR: isw: Could not find disk /dev/sdb in the metadata
no raid disks
Well, once again, it was Debian patches to the rescue. Just make sure you apply the latest dmraid_######.diff patches to your dmraid install (just like we did for grub, see below) and voila!:
root@dusk:/usr/src/dmraid/1.0.0.rc15# dmraid -ay
RAID set "isw_dadaadaecb_Ark" was activated
RAID set "isw_dadaadaecb_Ark1" was activated
RAID set "isw_dadaadaecb_Ark2" was activated


Booting with a failed primary HDD on a Linux RAID1 array

Thought it would be straightforward, and that the system would automagically take care of it by itself, think again:
  1. GRUB is dumb, until we tell it exactly what to do, so, assuming your /boot partition is located on sda1/sdb1, you need to make sure that you manually setup both disks, using:
    [root@whatever ~]# grub

    GNU GRUB version 0.95 (640K lower / 3072K upper memory)

    [ Minimal BASH-like line editing is supported. For the first word, TAB
    lists possible command completions. Anywhere else TAB lists the possible
    completions of a device/filename.]

    grub> root (hd0,0)
    Filesystem type is ext2fs, partition type 0xfd

    grub> setup (hd0)
    Checking if "/boot/grub/stage1" exists... yes
    Checking if "/boot/grub/stage2" exists... yes
    Checking if "/boot/grub/e2fs_stage1_5" exists... yes
    Running "embed /boot/grub/e2fs_stage1_5 (hd0)"... 15 sectors are embedded.
    Running "install /boot/grub/stage1 (hd0) (hd0)1+15 p (hd0,0)/boot/grub/stage2
    /boot/grub/grub.conf"... succeeded

    grub> root (hd1,0)
    Filesystem type is ext2fs, partition type 0xfd

    grub> setup (hd1)
    Checking if "/boot/grub/stage1" exists... yes
    Checking if "/boot/grub/stage2" exists... yes
    Checking if "/boot/grub/e2fs_stage1_5" exists... yes
    Running "embed /boot/grub/e2fs_stage1_5 (hd1)"... 15 sectors are embedded.
    Running "install /boot/grub/stage1 (hd1) (hd1)1+15 p (hd1,0)/boot/grub/stage2
    /boot/grub/grub.conf"... succeeded

    grub> quit

  2. If you have additional disks that you fsck (last columns of your fstab), be mindful that libsata will reorganize their names around, so if you set your /dev/sdc1 to be checked at bootime, you might end up getting stuck with fsck not finding the disk, and not being able to boot at all!


Booting fakeraid RAID5 Linux, the less half assed way

This will be the final episode of our ongoing installation of Linux on a nVidia MediaShield fakeraid RAID5 array.

By now, you should have a kernel and an initrd.gz image that allow you to boot onto your RAID5 partition, the only last remaining problem being that you need an external non RAID5 disk to do so. That disk could probably be put to better use, so let's remove it from the equation. And no, we're not gonna use an USB stick, CD-ROM or even a floppy, because what we need is a solution always at our fingertips, that we can rely on 24/7, without having to look for a flimsy little device/disc, that we're sure to lose or scratch anyway. Instead, we're going to use something MUCH better.

Re-introducing, the best invention since sliced bread: the fully hacked WRT54G, with supporting cast: PXE!

If by now you don't have a hacked WRT54G in your house, you're an idiot, and if you didn't get a motherboard + ethernet controller that supports PXE, you also need to rethink your life.

You'll find plenty of (seriously confusing) guides on how to use PXE, so I'll just cut down to the chase. What we need here is a PXE executable that can boot our vmlinuz + initrd.gz, as well as relinquish the boot operation to the default disk device, so that we can chose between Vista and Linux.
If you do the groundwork, you'll probably find out that GRUB can be compiled to be run from PXE. The only issue we have here is that the nForce forcedeth network driver is not embedded with GRUB 0.97, and while you can pick one up from gPXE (which is where all the network drivers from GRUB come from anyway), if you want to do things clean, you'll have to recreate the configure/Makefile settings to add the forcedeth, which is a major pain in the ass (or you can simply hijack one of the existing drivers files, and replace it with the forcedeth.c code, but this lazyman's option of choice is not really gratifying).

Instead, we're going to use PXELINUX, a spinoff of the Syslinux project.
Since our WRT router is using DNSMasq, we'll practically follow the instructions from the link above, so if you need more than what I am to present below, feel free to refer to the official documentation.
  1. Create a tftpboot directory on your multipurpose router. For convenience, I am creating mine in /share/tftpboot as the /share directory is already shared using Samba, and this of course gives us great convenience to setup our PXE server files
  2. Copy your vmlinuz and initrd.gz images in this directory
  3. Download and extract the latest syslinux.zip from kernel.org.
  4. Copy the pxelinux.0 from the syslinux.zip core/ directory into your tftpboot dir
  5. Copy menu.c32 from /com32/menu into your tftpboot dir
  6. It's also a nice feature to be able to boot DOS floppy images using PXE as well (eg: Win98 bootdisk, Memtest86+, etc.). To do that, copy memdisk from the memdisk/ directory to your tftpboot dir. Note that memdisk can also handle gzip compressed images, which can help reduce transfer time
  7. Optional: If you want to confirm that memdisk works, or if you simply want to have the Memtest86+ option, you can also download the compressed Memtest86+ v2.10 image that I am providing here. Note that this is the same memtestp.bin that you can download from http://www.memtest.org/ except padded to reach the standard 1.44 MB floppy size. Despite multiple attempts, I haven't yet found how to get memdisk to auto-pad floppy images...
    Oh, and the reason I use Memtest86+ rather than Memtest86 is that the latter didn't seem to handle my 4 GB RAM properly
  8. Create a pxelinux.cfg/ directory in your tftpboot dir
  9. Create a graphics.conf text file there, with the following content:
    menu color tabmsg 37;40      #80ffffff #00000000
    menu color hotsel 30;47 #40000000 #20ffffff
    menu color sel 30;47 #40000000 #20ffffff
    menu color scrollbar 30;47 #40000000 #20ffffff
    menu master passwd yourpassword
    menu width 80
    menu margin 22
    menu passwordmargin 26
    menu rows 6
    menu tabmsgrow 15
    menu cmdlinerow 15
    menu endrow 24
    menu passwordrow 12
    menu timeoutrow 13
    menu vshift 6
    menu passprompt enter password:
    noescape 1
    allowoptions 1
  10. Create a default text file in the pxelinux.cfg directory, and adapt the following content to your needs (NB: By default, this menu will apply to all PXE devices. If you want to target specific MACs, just change the "default" name to the MAC address of your interface (eg: "01-88-99-aa-bb-cc-dd"):
    default menu.c32
    prompt 0

    menu title PXE Boot Menu
    menu include pxelinux.cfg/graphics.conf
    menu autoboot Starting Local System in # seconds

    label bootlocal
    menu label ^Local System
    menu default
    localboot 0
    timeout 35

    label linux
    menu label Slackware 12.2 (RAID5)
    kernel vmlinuz
    append initrd=initrd.gz vga=791 vt.default_utf8=1

    label dos
    menu label DOS (Win98)
    kernel memdisk
    append floppy initrd=win98.gz

    label memtest
    menu label Memtest86+
    kernel memdisk
    append floppy initrd=memtestp.gz
  11. Now, you need to tell your DHCP server that it should handle PXE, and which files it should provide. If you are using DNSMasq, this is as trivial as adding the following lines:
    # PXE Booting
    # This is the file that will be ftpd's accross
    and then restarting the daemon (/etc/init.d/dnsmaq restart)

  12. Finally, you can enable PXE in your PC BIOS, and watch in awe as you can now conveniently boot whatever you want from the network. If it doesn't work, I'd suggest you run a test with memdisk and a bootdisk (eg: memtest), as it shouldn't require much of any configuration to run properly.

RE: Installing XBox controller on Vista 64

Well, I already gave you some tips, but each time I do it, it's a complete pain finding the right driver and getting it to work. I'll tell you; there are WAY TO MANY versions of the xbcd driver floating on the internet.

The one you want to use then is the one listed from this thread (0.2.6 at the time of this article - I also put a copy of the installer here if you need). Don't bother installing anything else.
Then the nice thing is that this latest version is already self signed, and the installer will also prompt you to install the driver's root CA, so if you're in test mode, you're golden.

2 things to know though:
- To access the setup utility, you need to have disabled UAC (use msconfig for that). You can re-enable it afterwards
- If you already installed an xbcd driver, or if it simply doesn't appear to work, just select "update driver" on the device, and point it to your Windows\Inf directory. The update should get you sorted.


Booting fakeraid RAID5 Linux, the half assed way

OK, by now you have a whole Linux system sitting idly on one of your RAID5 device mapper partitions. First thing you want to do then is edit the etc/fstab there to have the root filesysten point to the right device (in our case /dev/mapper/nvidia_aeejfdbep2). Not that it's actually necessary considered how we are going to boot, but it can't hurt.

If you've done your groundwork, you found out by now that using GRUB or LILO as is won't be of much help, as none of them is able to handle a RAID5 device mapper array. We don't have a choice her but have to run dmraid -ay before we try to access the disks, and of course, that means we need to build an initrd image.
As a side note, RAID1 or RAID0 shouldn't be an issue with GRUB, so you can probably follow this tutorial and complete the bootloader installation on your main RAID5 array, and have it work.

Now, our final solution here will still require an external partition with a /boot directory that the bootloader can refer to at boottime, but for the sake of this exercise, and also for our final solution, which will no longer require an external non RAID5 partition (more about that in the next post), we're gonna setup our RAID5 Linux system as close to standalone as possible, which means that what we ultimately want is the ability to run the bootloader from our RAID5 system (so that the day we have a bootloader that properly handles RAID5, we can just install it on the RAID5 MBR rather than the external disk, and ditch the latter in a heartbeat).
Unfortunatley, this means that we'll need to use GRUB rather than LILO, so we'll break things in 2 parts: First we'll configure initrd and setup LILO from the non RAID Linux to boot our RAID, and once we're there we'll setup GRUB to boot our RAID from the RAIDed Linux (but still using the non RAIDed boot). If you're confused, just hang on.

Part 1: Setting up initrd to boot the RAID5 Linux

Well, time and time again, I find more compelling reasons to use Slackware, the last one being /boot/README.initrd, which is installed by default, and in which Patrick Volkerding tells you anything you want to know about how to create initrd. Not that there is much you need to know in the end as:
root@stella# cd /boot
root@stella# mkinitrd -c
is all you need for now. The mkninitrd will have created a brand new initrd-tree and initrd.gz for you - isn't that nice?

Now, obviously, we need to add our dmraid executable to the initrd-tree and recreate initrd.gz. But if you're thinking "fine, we'll just pick up the exec", think again!
The dmraid executable we built was the dynamically linked version, so if you strace the files used, you'll see that we're gonna have to copy a whole bunch of libraries as well:
root@stella# strace -e trace=file dmraid -ay 2>&1 | more
execve("/sbin/dmraid", ["dmraid", "-ay"], [/* 35 vars */]) = 0
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY) = 3
open("/lib/libdevmapper.so.1.02", O_RDONLY) = 3
open("/lib/libc.so.6", O_RDONLY) = 3
open("/proc/mounts", O_RDONLY) = 3
RAID set "nvidia_aeejfdbe" already active
RAID set "nvidia_aeejfdbep1" already active
RAID set "nvidia_aeejfdbep2" already active
RAID set "nvidia_aeejfdbep3" already active
NB: The removed output above has to do with /proc, /dev or /sys, which won't be an issue.

The smart way (or lazy way, which is even better), is to compile dmraid as a static binary, so that we don't have to care about those pesky libraries. Therefore:
root@stella# cd /usr/src/dmraid/1.0.0.rc15/
root@stella# make clean
root@stella# ./configure --enable-static_link
root@stella# make
root@stella# ls -alF tools/dmraid /sbin/dmraid
-rwxr-xr-x 1 root root 204658 2009-02-05 23:01 /sbin/dmraid*
-rwxr-xr-x 1 root root 816664 2009-02-06 16:47 tools/dmraid*
root@stella# cp tools/dmraid /boot/initrd-tree/sbin/
That's 600 KB more to our initrd right there, but at least we know that we have everything we need.
Now, all that's left is editing the init script in /boot/initrd-tree to call our command.
Depending on your distro, the name & content of the init script could be very different, so you might have to be creative. In the case of slackware, the init script is called "init" (which makes sense, because then you don't have to specify it as a kernel parameter), and in the
if [ "$RESCUE" = "" ]; then
section, which already contains some disk detection routines, we're gonna add:
  # Initialize DMRAID:
if [ -x /sbin/dmraid ]; then
/sbin/dmraid -ay
Now, we shall rebuild our initrd:
mkinitrd -r /dev/mapper/nvidia_aeejfdbep2

The stage is now setup to see if we can boot our RAID5 system using LILO, by adding the following section in /etc/lilo.conf:
image = /boot/vmlinuz
initrd = /boot/initrd.gz
root = /dev/mapper/nvidia_aeejfdbep2
label = RAID5_Linux
Now, reinstall LILO:
root@stella# lilo
Warning: '/proc/partitions' does not match '/dev' directory structure.
Name change: '/dev/dm-0' -> '/dev/disk/by-name/nvidia_aeejfdbe'
Warning: Name change: '/dev/dm-1' -> '/dev/disk/by-label/Vista64'
Warning: Name change: '/dev/dm-2' -> '/dev/disk/by-name/nvidia_aeejfdbep2'
Warning: Name change: '/dev/dm-3' -> '/dev/disk/by-label/Media'
Added RAID5_Linux *
Added Slack_New
Added Slack_Old
Added Rescue_1
4 warnings were issued.

Don't worry too much about the warnings. Just reboot and, yay, it works!... Err, well... kinda, because while you should have seen the dmraid disks being mapped, and you do end up with everything running as it should from the RAID5 partition, you might end up with a boot where the rc.d/init scripts from Slackware are not being displayed on the console at bootime as they should.
If you look in /var/log/messages, you will see that all the scripts do indeed run, but you're being left with a very silent screen right before you end up with the prompt.

The problem is actually due to udev screwing up the /dev repository after the root filesystem is mounted. The solution to that? Keep the /dev used by the kernel even after root is mounted by compiling your kernel with:
Device Drivers ---> Generic Driver Options ---> "Create a kernel maintained /dev tmpfs (EXPERIMENTAL)" and "Automount devtmpfs at /dev" bot selected.

Part 2: Setting up GRUB on the RAID5 Linux partition

There are 2 (well 3) reasons why we want to replace LILO with GRUB here:
1. GRUB is more likely to be patched for full RAID5 support compared to LILO, so when that happens, we want to be ready
2. If you're using RAID0/RAID1 instead of RAID5, GRUB should actually be able to install the bootloader on your RAID array
3. Having GRUB handle RAID takes some trickery which you probably want to read about.

Once more, we'll be using grub 0.97, however, if you use the vanilla version, no matter what you do or where your /boot partition might be located (even on a standard non-RAID disk), you might end up with the infamous:
grub> setup (hd0)
Checking if "/boot/grub/stage1" exists... no
Checking if "/grub/stage1" exists... no

Error 2: Bad file or directory type
AFAIK, this could be due to GRUB 0.97 being unable to access ext3 256 bytes inodes, OR it could happen if you have more than 2 GB RAM, or it could have to do with the 2.6 kernel new geometry. Well, all I know is that one of the grub 0.97 patches from Debian fixes the problem. Thus:
4) Reinstall grub on RAID:
root@stella# wget ftp://alpha.gnu.org/gnu/grub/grub-0.97.tar.gz
root@stella# tar -xvzf grub-0.97.tar.gz
root@stella# cd grub-0.97
root@stella# wget http://ftp.de.debian.org/debian/pool/main/g/grub/grub_0.97-47lenny2.diff.gz
root@stella# gunzip grub_0.97-47lenny2.diff.gz
root@stella# patch -p1 < grub_0.97-47lenny2.diff
root@stella# cat debian/patches/00list
OK, that last line gives us the order in which we should do the installation of the patches, so from there on you just need to run a bunch of:
patch -p1 < whatever.patch
In the order provided from the 00list file (i.e. starting with cvs-sync.patch and ending with use_grub-probe_in_grub-install.diff). Once you're there, just compile and install grub so that we move to the final phase. Now, we'll still tell GRUB to use our /boot directory on /dev/sdc1, because we don't really have a choice here (if you don't believe me, you can try installing on RAID5 and see your 'setup (hd#)' command fail miserably), but we will also tell it how to "see" our RAID5 array, and to be able to do that, we will need to know our disk geometry, which we can get from fdisk. What we want are the C(ylinders) H(eads) and S(sectors) value:
root@stella# fdisk /dev/mapper/nvidia_aeejfdbe
Command (m for help): p

Disk /dev/mapper/nvidia_aeejfdbe: 2000.4 GB, 2000409722880 bytes
255 heads, 63 sectors/track, 243202 cylinders
These days, most disks have 255 heads and 63 tracks anyway (which are the greatest values you can set), so what you really need is the number of cylinders. This we will use to provide the geometry of our RAID5 "disk" to GRUB, in C H S order, because it is unable to figure it our by itself. And also, since we are doing a GRUB installation from scratch, we have to copy the stage1 & stage2 files to the /boot/grub directory (which is information that the clueless people using ready made packages are apparently unable to provide - damn you Ubuntu!):
mount /dev/sdc1 /mnt/hd
mkdir /mnt/hd/boot/grub
cp /usr/local/lib/grub/i386-pc/* /mnt/hd/boot/grub/
grub --device-map=/dev/null
grub> device (hd0) /dev/sdc

grub> device (hd1) /dev/mapper/nvidia_aeejfdbe

grub> geometry (hd1) 243202 255 63
drive 0x81: C/H/S = 243202/255/63, The number of sectors = -387927166, /dev/map
Partition num: 0, Filesystem type unknown, partition type 0x7
Partition num: 1, Filesystem type is ext2fs, partition type 0x83
Partition num: 2, Filesystem type unknown, partition type 0x7

grub> find /boot/grub/stage1

grub> root (hd0,0)
Filesystem type is ext2fs, partition type 0x83

grub> setup (hd0)
Checking if "/boot/grub/stage1" exists... yes
Checking if "/boot/grub/stage2" exists... yes
Checking if "/boot/grub/e2fs_stage1_5" exists... yes
Running "embed /boot/grub/e2fs_stage1_5 (hd0)"... 16 sectors are embedded.
Running "install /boot/grub/stage1 (hd0) (hd0)1+16 p (hd0,0)/boot/grub/stage2
/boot/grub/menu.lst"... succeeded
Good, now we're ready to create our boot menu:
vi /mnt/hd/boot/grub/menu.lst

default 0
timeout 3

title Vista (64 bit)
rootnoverify (hd1,0)
chainloader +1

title Slackware 12.2 (RAID5)
root (hd1,1)
kernel (hd0,0)/boot/vmlinuz root=/dev/mapper/nvidia_aeejfdbep2
initrd (hd0,0)/boot/initrd.gz
This allows us to boot both Vista and Slackware on the RAID5 array using the /boot partition on the non RAID disk. Note that at this stage, it is probably a good idea to duplicate the /boot directory from the non RAID to the RAID partition, and recreate a small boot partition from scratch on the non RAID.

Of course, as mentionned before, because we still need a non RAID HDD, this is an half assed solution. In the next post, we'll see a better assed solution, where we do away with that extra HDD, and where we'll explore some new interesting stuff...


And here we go again - RAID5 fakeraid + Linux

It's that time of the decade where I get a new machine, this time an nVidia MCP79 (a.k.a. GeForce 9400) based motherboard from Gigabyte. Oh, and yes, the MCP79 is the same all-inclusive nForce chipset nVidia uses in the new MacBook Pros, as well as their Atom "can of whoop-ass" for set top HDTV boxes.

As most people, I'm pleasantly surprised by the features of the chipset. My goal was to build an HTPC, and with one good durable mobo (with both HDMI and optical SPDIF), the adding of a 45 nm quad core and 4 GB dirt cheap DDR2 RAM, I should have a solution that will last for some time. Oh, and of course, since we're hopefully going to store a lot of media data there, we can't forget the 3x 1 TB Samsung SpinPoint HDDs in a RAID5 array, which is what brings us here today.

Yep, as you guessed from the title, it's ye olde getting Linux to work with fakeraid. And the first thing I gotta say is I'm sick and tired of all the posts you see on the net where people asking how to make Linux work with their fakeraid are met with a "why don't you use Linux's md instead".
Well, I'm sorry, but there are still people out there who want to dual boot with Vista and trust nVidia RAID5 driver (MediaShield) enough not to want to make a complete mess of their Windows installation. Hell, I'd rather spend time figuring out how to make my RAID5 work in Linux than have to spend time doing the same thing in Windows. Plus, I like the convenience of having my BIOS handle things like RAID.

Here we are then, with Vista installed and painfully updated at last (see below) and a blank partition on the nVidia RAID5 MediaShield array that's just dying to get Linux installed.

OK, it's not that I mind a challenge here, but I've got a blank HDD lying around, so this time, what we're going to do is install Linux on that standalone drive, conf it so that it sees the RAID5 partition, and then move over our system rather than have to create our own custom RAID5 installation CD.

As usual, I'm gonna use the latest Slackware (12.2) so ymmv.

1. Slackware install with ALL the options you really want in the end (we'll be using that partition as the source) and LILO booting the single HDD = piece of cake. Just make sure that you don't install LILO on anything else BUT the HDD that's not part of the array
2. First bad surprise - if you keep your 2.6 kernel as is, no matter what you try, dmraid will return:
ERROR: device-mapper target type "raid45" not in kernel
Don't waste your time changing the raid45 to raid456 identifiers in dmraid either - you'll still get the same error. The kernel actually needs to be patched for dmraid to be happy.

[UPDATED]One year later, and still a mess. As of 2.6.35, the dm-raid45 module still hadn't been integrated to the kernel, plus the evil people at Red Hat who were supposed to maintain that module have completely dropped the ball, the Gentoo people also have dropped the ball (after 2.6.31) and the last set of dm-raid45 patches I could only go to 2.6.33 (and don't work against 2.6.35). So I guess we're stuck with 2.6.33 then. This last set of dmraid patch can be found from Mandriva. Can't help but find it strange that, while the dm-raid45 module is commonly used in Ubuntu (except that dmraid itself is useless with large disks as it doesn't support GPT), nobody seems to care about trying to merge it with the official kernel tree. Oh well...
root@stella# cd /usr/src/linux-2.6.33/
root@stella# wget http://tmb.mine.nu/Mandriva/Cooker/dm-raid/dm-raid45_2.6.33-rc1-20091126.patch
root@stella# patch -p1 < dm-raid45_2.6.33-rc1-20091126.patch
root@stella# wget http://tmb.mine.nu/Mandriva/Cooker/dm-raid/dm-raid45-buildfix-for-2.6.33.patch
root@stella# patch -p1 < dm-raid45-buildfix-for-2.6.33.patch
OK, so you just go through your usual kernel recompile. Now, a couple of things I wanna point out:
- You do want to reduce the size of your kernel if you're planning to remove the standalone HD and still boot your RAID5 array Linux partition with a decent solution
- Of course you want to add Device mapper support (Device drivers -> Multiple devices driver support (RAID and LVM)) and the new experimental "RAID 4/5 target" that was added by the kernel patch
- Despite being a Gb adpater, the nForce Ethernet driver (forcedeth) is to be found in: Ethernet (10 or 100Mbit) -> EISA, VLB, PCI and on board controllers -> nForce Ethernet support
- if you're using ext4 for root, don't forget to include ext2 support as well, as your root partition cannot be mounted without it.

Once you have a kernel that boots, you can move on to the dmraid install. This time, no need for devmapper. Just download the current dmraid source from http://people.redhat.com/~heinzm/sw/dmraid/src/:
root@stella# cd /usr/src
root@stella# wget http://people.redhat.com/~heinzm/sw/dmraid/src/dmraid-current.tar.bz2
root@stella# tar -xjvf dmraid-current.tar.bz2
root@stella# cd dmraid/1.0.0.rc15
root@stella# ./configure; make; make install
root@stella# dmraid -ay
RAID set "nvidia_aeejfdbe" was activated
RAID set "nvidia_aeejfdbep1" was activated
RAID set "nvidia_aeejfdbep2" was activated
RAID set "nvidia_aeejfdbep3" was activated
Yay! it works!

If you only see see the RAW disk (nvidia_aeejfdbe) but not the partitions, that's probably because you're using a GPT disk. In that case, you need to also run kpartx as follows:
root@stella# kpartx -a -v /dev/mapper/nvidia_aeejfdbe
add map nvidia_aeejfdbe1 (252:1): 0 262144 linear /dev/mapper/nvidia_aeejfdbe 34
add map nvidia_aeejfdbe2 (252:2): 0 209715200 linear /dev/mapper/nvidia_aeejfdbe 264192
add map nvidia_aeejfdbe3 (252:3): 0 186478592 linear /dev/mapper/nvidia_aeejfdbe 209979392
add map nvidia_aeejfdbe4 (252:4): 0 11324626944 linear /dev/mapper/nvidia_aeejfdbe 396457984
kpartx itself can be obtained from the multipath-tools.

OK, so now we can get going. Be sure you format the RELEVANT partition. In my case, I'll be using nvidia_aeejfdbep2, the second partition on the RAID5 array for the GNU/Linux system.
root@stella# mkfs.ext4 /dev/mapper/nvidia_aeejfdbep2
root@stella# mount /dev/mapper/nvidia_aeejfdbep2 /mnt/hd
root@stella# mkdir /mnt/hd/proc
root@stella# mkdir /mnt/hd/sys
root@stella# cp -ax / /mnt/hd
This could take a while...
Note that the -x option ensures that we stay on a single file system

OK, in the next post we'll see the grub way to (kinda) boot this whole mess


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Here's a link to the hosts file I use on my Windows systems:


Windows update error 0x8024402c

Well, like everybody else, this error has been driving me nuts. Plus it manifested itself in such a weird way I couldn't believe.

I already had that issue last week on a brand new Vista 64 install, and somehow, it appeared that resetting the LAN paramaters to default did the trick, and after a short hour struggle, I was able to apply the updates.

I was not so lucky with that old laptop of mine running XP, which was badly in need of critical updates, but that couldn't seem to download them. Well, actually, at first, it started to download the updates alright (got through about 8-10 of them) but then it failed! Tried every hint from the link above. None worked...

This is a job for... Is it a bird? Is it a plane? No, it's Wireshark!
OK, so Wireshark reveals that, despite everything Microsoft wants to make you believe, the issue is really with au.download.windowsupdate.com not being resolved. Of course, one has to wonder why an Irish based Windows has to pick up its updates from Australia, but hey, that's Microsoft for you.
Indeed, a few tests from the commandline show that au.download.microsoft.com is indeed not resolvable. OK, let's see what the DSL router (which can also do basic diagnostic checks) has to say about it... WTF? The DSL router sees no issue there:
Resolving au.download.windowsupdate.com ...
Reply from
Reply from
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Ping Host Successful
And this is where it gets really weird, as it appears that my Linux machines also cannot resolve the host... while the router can?!?! No way!

OK, by now I need to apply these updates badly, and therefore, yes, you got it, we're gonna edit the systems32/drivers/etc/hosts file of course and get done with it.
So here goes: au.download.windowsupdate.com
and try downloading the updates again (with Wireshark still running in the background).
What the hell?!? No difference - We still get DNS requests for au.download.windowsupdate.com that don't seem to resolve. But how on earth is that possible with a triple checked hosts file?

The answer of course is that Microsoft deliberately screwed up their DNS resolution so that their update servers can NOT be overridden by the hosts file. Yeah, I can understand the logic of it, but how about relying on https and certificates instead, to check that the server is legit, rather than breaking down DNS. Talk about another half assed approach to security...

Well, that will teach me to try to work around a problem rather than solve it, because with no DNS override, I'm back to square one. And I'm not really willing to install my own DNS server just to work around this problem either.

Now, further use of nslookup with various Irish DNS seem to indicate that they ALL have the same issue??? Is someone out there to get me or what, because none of this makes any sense!

At this stage, instead of banging your head against the wall, you gotta try to apply logic. If all of the Irish DNSs were failing to resolve the Windows Update servers, you'd probably get people armed with pitchforks on the streets within minutes, so I must be doing something wrong.
A quick change of NS lookup tool actually confirms it (DON'T USE NSLOOKUP ANY MORE STUPID!). dig quickly shows that it's only the DNS that I was using (Eircom's & - never trust the incumbant!) can't resolve the bloody server, while my own ISP's DNS can.

A quick change of DNS servers on the DSL router, a full reboot (ipconfig /release + /renew would probably have done the trick, but with M$, you can never be too sure), and Windows Update is happy again.

Good thing I didn't have anything better to do this morning. And just to sum up the lessons for today:
- 0x8024402c happens if Windows cannot resolve the IP of the download servers
- Windows update CAN switch download servers on the fly while downloading (!)
- Use Wireshark to find out which download servers Windows Update is trying to use
- Windows name resolution is screwed so that it will always try to use DNS and not the hosts file for the download servers
- Don't trust what your DSL router tells you about Name Resolution - it might not be using the configured DNS servers!
- DON'T USE NSLOOKUP ANY MORE! Use dig instead.
- Screw Eircom!