Technology has evolved since the last MythTV PVR I built, as chronicled here.  Here’s the latest techniques and tech that I’ve used to (start) build(ing) my current PVR. I’ll update this article as I go, as there’s been some bumps along the way, so completion of the project has been slower than I anticipated.

Requirements for my new PVR include:

• Linux operating system for cost and flexibility reasons
• Quiet! Fan-less operation if at all possible, external power supply ok
• Small form factor, black case to fit in with my current home theater gear
• Video capture with MPEG-2 hardware acceleration to help keep the CPU needed as small as possible, in an expansion card format for the most compact physical footprint .. additionally there must be at least two independent tuners
• Analog tuners, but would be good if they were capable of digital for when I eventually move to digital/HD
• IR receiver and transmitter capability for easy remote control and ability of the PVR to use my current set-top box as a source (gives me all the cable company movies and channels that are not available via the basic cable connection
• Ability to schedule at least 10 shows and retain 5 episodes of each show .. also ability to schedule based on show name alone
• Ability to perform post-recording processing, such as removing commercials or changing formats
• Should be able to use a pre-packaged distribution for most if not all of the functions .. I know it’s a home-brew, but I’m tired of messing with individual packages, firmware, and custom codes to make it work. Using a distribution package makes it easier to maintain through updates.
• Want to purchase the parts from the same supplier if possible (ended up using newegg.ca)

Since I already run MythTV, it was an obvious starting point and given I don’t have an affinity to a specific Linux distribution, I looked at Mythbuntu and Mythdora since I’m familiar with and already run both Ubuntu and Fedora distributions.

After downloading the Mythbuntu 10.10 ISO disk image, I discovered I didn’t have my USB DVD drive, so I wanted to create a bootable USB flash disk.  I followed the excellent instructions at https://help.ubuntu.com/community/Installation/FromUSBStick and successfully burned a bootable Mythbuntu disk on a 2GB USB flash disk via a Ubuntu VM running on my MacBook Pro.

The Hardware

The hardware that I chose to use included:

• An Antec ISK-300-65 case, good for fan-less operation
• ASUS AT5IONT-I mainboard dual core Atom D525 CPU
• Hauppauge WinPVR-2250 dual tuner PVR card with MPEG-2 hardware acceleration (PCI-express)
• 4GB DDR3 SO-DIMM memory (2x 2GB)
• 2x 750GB 2.5″ SATA HDDs
• My existing Microsoft MCE USB IR receiver/blaster and remote

I evaluated the very cool and potentially high performance hybrid HDD/SSD disks, but there were too many experiences users expressed that were sub-optimal, most stating the technology is too new. Having a terabyte 2.5″ disk with 4GB of SSD would be sweet, but for now I’m just sticking with 750GB 7200RPM 2.5″ SATA disks. Since I changed my mind and I’m not going to put a DVD drive into the case, I chose to put another HDD in and mirror them up (since there are two SATA adapters on the mainboard and space in the case for two HDD).

The ASUS mainboard is designed for fan-less operations, and coupled with the Antek case as one massive heat sink, it is incredibly quiet. Video outputs are all handled by the mainboard versus the video capture card and include DVI, HDMI and component video outputs. On initial power on, I was somewhat underwhelmed, since although the power on button turned on the blue power light on the mainboard, then spun up the disk and fan, no joy on the mainboard BIOS POST. After some Googling, I found the Asus board uses the very finicky Intel memory controller that is used with the Atom CPU. I purchased a pair of KVR1066D3S7/1G (Kingston 1GB 204-Pin DDR3 SO-DIMM DDR3 1066 (PC3 8500) Laptop Memory) to boot the AT5IONT-I far enough to get the BIOS updated. See the forum thread here for other people’s experiences. Version 312 of the ASUS BIOS did not support the 2GB DIMMs so I was a bit annoyed that I had to purchase 1GB DIMMs (Kingston KVR1066D3S7/1G) in order to get into the BIOS.  I downloaded the 316 BIOS ROM image from the ASUS website and put it onto a FAT formatted USB memory stick, thinking I’d have to go through the pain of booting some form of Windows or DOS to run some lame BIOS updater utility. I was pleasantly surprised to find a BIOS update utility built into the BIOS! All I had to do is plug in the USB stick and select the option to update the BIOS. It worked! Not only the most painless BIOS update I’ve ever done, now the 2GB memory DIMMs work (anyone want to buy my 1GB DIMMs for the cost of shipping?). On to the installation of Mythbuntu.

I originally wanted to have a slim DVD drive to play DVDs but then realized that I don’t even have any movies on DVD any more.  All the oldie goldies that I had, I now have copies in iTunes. Since the mainboard only supports two SATA interfaces, I chose to reserve one for a future redundant HDD (as it turns out I just ordered the extra disk when I purchased the 1GB DIMMs).

The Hauppauge card is a dual-tuner analog/digital that has an IR receiver and blaster – so it can change channels on a cable set top box. The 2250 also has dual tuners so that the conflicts that I often encountered with a single tuner can be avoided. 

OS Install

I tried a couple of All-In-One distributions (Mythdora and Mythbuntu) and even a couple of versions of each.  Seemed like I ran into issues with both distros in different areas. Mythbuntu 10.10 wouldn’t save the Video Sources. Mythdora had a better setup interface than Mythbuntu 10.10, but would not setup a default route for some reason – all the subsequent updates and package installs would obviously fail.  Sigh. Doing a base install of Fedora 14 then installing from ATrpm repositories would go better for the OS install (including full mdadm mirroring of the two SATA drives), but compiling the Hauppauge HVR 2250 analog driver from Steve Toth’s excellent support site would fail with usb_ function call mismatch errors. Apparently the usb_ memory function definitions have changed in recent 2.6 kernels. Arrrg!

Fortunately I set this aside for a while and in the mean time, Mythbuntu came out with release 11.04 … would it work??

So now it works for analog .. exactly what I wanted. Ironically I don’t need the digital tuners for a while yet.

Here’s how:

I downloaded Mythbuntu 11.04 64 bit ISO and created bootable USB flashdrive via
http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3 on my HP notebook (Windows 7). Booted off the USB and selected the Install option. Ultimately I wanted to partition the drives and use mdadm software RAID 1 with LVM2 on top for partition and filesystem management options. No matter how I tried, the Mythbuntu 11.04 installer just would not let me do an install in that configuration. So I did a vanilla install, configured things the way I wanted THEN did a transition to LVM2 mirroring setup.

1. Use USB stick to boot Mythbuntu 11.04 and perform MythTV install
Use the following partition table on /dev/sda with all primary partitions and ignore /dev/sdb for now – note you’ll need to use /srv for the MythTV storage fs as those are the mount point options available in the install image. Don’t worry, we’ll change it later to /storage and only /dev/sda1 (/boot) will remain after we’re done the conversion to LVM mirroring.
/dev/sda1 /boot 150MB
/dev/sda2 / 8GB
/dev/sda3 swap 8GB
/dev/sda4 /srv 630GB

Once the install is done, change the /srv filesystem to /storage and make it owned by user mythtv then create the storage directories that MythTV will use for LiveTV and Recordings.
umount /srv
vi /etc/fstab (change /srv to /storage)
mkdir /storage
mount /storage
mkdir /storage/livetv
mkdir /storage/recordings
mkdir /storage/db_backups
chown mythtv:mythtv /storage/*

2. Compile V4L code
Install tools needed to get and build the code
apt-get install git patch patchutils libproc-processtable-perl gcc make

Get the code base and build it – based on the forum post “How to Obtain, Build and Install V4L-DVB Device Drivers”
git clone git://linuxtv.org/media_build.git
cd media_build
./build
sudo make install


3. Download HVR 2250 firmware and install in /lib/firmware
wget http://www.steventoth.net/linux/hvr22xx/firmwares/4019072/NXP7164-2010-03-10.1.fw
sudo cp NXP7164-2010-03-10.1.fw /lib/firmware

I found that the HVR 2250 card wasn’t completely recognized even with the firmware in place, as seen in dmesg output .. and no /dev/video* or /dev/dvb/… devices were created. Googling found a few forum posts that discuss the issue .. the solution: create /etc/modprobe.d/saa7164.conf and force a card selection.

Jun 23 22:17:54 pvr kernel: [10.642158] saa7164 driver loaded
Jun 23 22:17:54 pvr kernel: [10.642321] saa7164 0000:07:00.0: PCI INT A -> GSI 19 (level, low) ...
Jun 23 22:17:54 pvr kernel: [10.643371] saa7164[0]: Your board isn't known (yet) to the driver.
Jun 23 22:17:54 pvr kernel: [10.643376] saa7164[0]: Try to pick one of the existing card configs via
Jun 23 22:17:54 pvr kernel: [10.643380] saa7164[0]: card=<n> insmod option.  Updating to the latest
Jun 23 22:17:54 pvr kernel: [10.643384] saa7164[0]: version might help as well.
Jun 23 22:17:54 pvr kernel: [10.643395] saa7164[0]: Here are valid choices for the card=<n> insmod option:
Jun 23 22:17:54 pvr kernel: [10.643403] saa7164[0]:    card=0 -> Unknown
Jun 23 22:17:54 pvr kernel: [10.643410] saa7164[0]:    card=1 -> Generic Rev2
Jun 23 22:17:54 pvr kernel: [10.643417] saa7164[0]:    card=2 -> Generic Rev3
Jun 23 22:17:54 pvr kernel: [10.643424] saa7164[0]:    card=3 -> Hauppauge WinTV-HVR2250

To set a card number option, create a modprobe directive file /etc/modprobe.d/saa7164.conf
options saa7164 card=3

Now reboot and watch the dmesg output to ensure the firmware is loaded properly
Aug 18 19:31:29 pvr1 kernel: [24.480644] saa7164 driver loaded
Aug 18 19:31:29 pvr1 kernel: [24.480891] saa7164 0000:07:00.0: PCI INT A -> GSI 19 (level, low) ...
Aug 18 19:31:29 pvr1 kernel: [24.490973] CORE saa7164[0]: subsystem: 0070:8891, board: Hauppauge WinTV-HVR2250 [card=3,insmod option]
Aug 18 19:31:29 pvr1 kernel: [24.490992] saa7164[0]/0: found at 0000:07:00.0, rev: 129, irq: 19, latency: 0, mmio: 0xfb800000
Aug 18 19:31:29 pvr1 kernel: [24.700362] saa7164_downloadfirmware() Waiting for firmware upload (NXP7164-2010-03-10.1.fw)
Aug 18 19:31:29 pvr1 kernel: [27.153217] saa7164_downloadfirmware() firmware read 4019072 bytes.
Aug 18 19:31:29 pvr1 kernel: [27.153227] saa7164_downloadfirmware() firmware loaded.
Aug 18 19:31:29 pvr1 kernel: [27.153257] saa7164_downloadfirmware() SecBootLoader.FileSize = 4019072
Aug 18 19:31:29 pvr1 kernel: [27.153269] saa7164_downloadfirmware() FirmwareSize = 0x1fd6
Aug 18 19:31:29 pvr1 kernel: [27.153276] saa7164_downloadfirmware() BSLSize = 0x0
Aug 18 19:31:29 pvr1 kernel: [27.153282] saa7164_downloadfirmware() Reserved = 0x0
Aug 18 19:31:29 pvr1 kernel: [27.153289] saa7164_downloadfirmware() Version = 0x1661c00
Aug 18 19:31:29 pvr1 kernel: [27.304006] Modules linked in: nvidia(P+) snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel(+) ir_lirc_codec lirc_dev ir_mce_kbd_decoder ir_sony_decoder snd_hda_codec ir_jvc_decoder snd_hwdep snd_pcm snd_seq_midi rc_rc6_mce psmouse ir_rc6_decoder ir_rc5_decoder mceusb serio_raw snd_rawmidi ir_nec_decoder joydev snd_seq_midi_event rc_core snd_seq saa7164(+) snd_timer snd_seq_device snd xhci_hcd asus_atk0110 dvb_core v4l2_common videodev media v4l2_compat_ioctl32 tveeprom soundcore snd_page_alloc lp parport usbhid hid ahci r8169 libahci
Aug 18 19:31:35 pvr1 kernel: [34.380040] saa7164_downloadimage() Image downloaded, booting...
Aug 18 19:31:35 pvr1 kernel: [34.490037] saa7164_downloadimage() Image booted successfully.
Aug 18 19:31:36 pvr1 kernel: [36.830033] saa7164_downloadimage() Image downloaded, booting...
Aug 18 19:31:38 pvr1 kernel: [38.270702] saa7164_downloadimage() Image booted successfully.
Aug 18 19:31:38 pvr1 kernel: [38.996628] DVB: registering new adapter (saa7164)
Aug 18 19:31:38 pvr1 kernel: [38.999488] saa7164[0]: registered device video0 [mpeg]
Aug 18 19:31:39 pvr1 kernel: [39.231624] saa7164[0]: registered device video1 [mpeg]
Aug 18 19:31:39 pvr1 kernel: [39.443888] saa7164[0]: registered device vbi0 [vbi]
Aug 18 19:31:39 pvr1 kernel: [39.444038] saa7164[0]: registered device vbi1 [vbi]


4. Run MythTV Backend setup, use IVTV MPEG driver and /dev/video0, /dev/video1

This configuration will result in the NTSC (analog) tuners to function with MythTV by initializing the tuner as an “IVTV MPEG-2 Encoder” defined for /dev/video0 and /dev/video1.

<I’ll post an update here for each of the backend setup steps, but for now follow the setup steps in order starting with General>

Under Storage, change the default directories for Recordings, LiveTV and Database Backups to the directories you created in step 1.

5. Setup mail transport agent so we can send status email
apt-get install postfix bsd-mailx

Since I locate the PVR behind a firewall on a residential Internet connection, I choose “Internet connected with Smart (Relay) host”
shawmail.cg.shawcable.net

6. Fix up some of the annoying outstanding problems

Arrow Buttons Repeat

For some reason, the Windows Media Center remote control IR codes are working but arrow button presses cause double movements. Huh? Ok, Google solves it:

MCE remote menu entries skipping twice for every button push
http://www.mythtv.org/wiki/MCE_Remote#Arrow_Buttons_Repeat

When navigating the menus in MythTV, it may appear that each time you hit the up or down arrow, that the button his hit twice but if you are using irw, the button only appears to be pressed once. This is likely caused by another kernel module that is attempting to treat the MCE remote as a keyboard. As a test try unloading a few modules
modprobe -r ir_rc6_decoder
modprobe -r rc_rc6_mce
modprobe -r ir_rc5_decoder

Since this solved the problem, the post author suggests the following command on system boot (in /etc/rc.local)
echo lirc > /sys/class/rc/rc0/protocols

Audio Pauses and Stutters

Turns out the default 4096 buffer size is too small for this system, so I increase it to 16384 (trial and error).

Put these lines in /etc/rc.local:

# prevent Arrow Button repeat
echo lirc > /sys/class/rc/rc0/protocols
# increase of audio buffer - from 4096 default to 16384
echo 16384 | tee /proc/asound/card0/pcm1p/sub0/prealloc

7. Setup the Disk Mirroring

I’m not going to use mdadm (dang it!) because mdadm (3.1.4) breaks initramfs (forum posts here). People upgrading Ubuntu to the “natty” release experienced this behavior where initramfs could not mount /root. For now I’ll use LVM2 to do the mirroring of

/
swap
/storage

but /boot will still be a standalone ext4 partition and filesystem on /dev/sda1. For recovery if /dev/sda dies, I’ll partition /dev/sdb the same and keep /dev/sdb1 in sync with /dev/sda1 – as well as have grub install a boot loader on both /dev/sda and /dev/sdb.  With the Asus AT5IONT-I mainboard, you can designate which SATA disk is the “Primary” and which is the “Secondary”. Worst case, if /dev/sda dies the Secondary drive can be manually mapped to the Primary disk (/dev/sda). Whew. A lot of extra work because mdadm is broken!

7.1. Install the lvm2 package

apt-get install lvm2

7.2. Partition the second drive with the desired end state

fdisk /dev/sdb

primary partition 1, 150M, set active, partition type flags “83″ (normal Linux fs)
primary partition 2, rest of the disk, partition type flags “fd” (Linux logical volume)

7.3. Setup the first LVM partition for pvr on /dev/sdb

# initialize the LVM volume
pvcreate /dev/sdb2
pvdisplay /dev/sdb2
# create the volume group
vgcreate rootvg /dev/sdb2
# create the logical volumes (with extents from one physical disk)
lvcreate -L 8G -n lv_root rootvg
lvcreate -L 8G -n lv_swap rootvg
lvcreate -L 650G -n lv_storage rootvg

This gives us the volumes we’ll use in our final configuration. Go ahead a get the filesystem contents copied across to the new LVM volumes.

# create the filesystems
mkfs.ext4 /dev/rootvg/lv_root
mkfs.ext4 /dev/rootvg/lv_storage
mkswap /dev/rootvg/lv_swap
# copy the old fs to new fs
mkdir /mnt/root
mount /dev/rootvg/lv_root /mnt/root
cd /
find . -xdev -print | cpio -pmd /mnt/root
umount /mnt/root
mkdir /mnt/storage
mount /dev/rootvg/lv_storage /mnt/storage
cd /storage
find . -xdev -print | cpio -pmd /mnt/storage
umount /mnt/storage

7.4. Update boot configuration to use LVM root volume

Copy the /dev/sda1 /boot filesystem to /dev/sdb1 for a backup in case something goes horribly wrong, you’ll at least have a starting point to recover.

To update GRUB to use the LVM device, add GRUB_DEVICE=/dev/mapper/rootvg-lv_root
to /etc/default/grub and disable the UUID volume label tracking by uncommenting the GRUB_DISABLE_LINUX_UUID=true line.

Update the /boot/grub/grub.cfg by running
cp /boot/grub/grub.cfg /boot/grub/grub.cfg.orig
update-grub -o /boot/grub/grub.cfg
You should see update-grub detect the original boot env on /dev/sda1 (/boot) with a root of /dev/sda2 (where we configured /) and you should also see it detect the new root environment on /dev/mapper/rootvg-lv_root.

Then install the grub boot environment on /dev/sda and optionally /dev/sdb. Note /dev/sdb will not have a boot block or env loaded yet, so no worries about having to save what might be there.
grub-install /dev/sda
grub-install /dev/sdb

Update the /etc/fstab to swing the filesystems over to the LVM volumes – update the device specs from their UUID labels to /dev/mapper/rootvg-lv_root, /dev/mapper/rootvg-lv_swap and /dev/mapper/rootvg-lv_storage
cp /etc/fstab /etc/fstab.orig
vi /etc/fstab

It should look something like
# / was on /dev/sda2 during installation
#UUID=fc0fa1e9-e2b6-4d11-9a51-d3c432bb3137 / ext4 errors=remount-ro 0 1
/dev/mapper/rootvg-lv_root / ext4 errors=remount-ro 0 1
# leave /boot alone
/dev/sda1 /boot ext4 defaults 0 2
# /storage was on /dev/sda4 during installation
#UUID=131514d2-3911-45df-8d6f-b9a19f2379bb /storage ext4 defaults 0 2
/dev/mapper/rootvg-lv_storage /storage ext4 errors=remount-ro 2
# swap was on /dev/sda3 during installation
#UUID=eedc9a3b-d957-4904-988e-32b117def5ac none swap sw 0 0
/dev/mapper/rootvg-lv_swap none swap sw 0 0

This is the nail-biting time, now reboot. When GRUB comes up and shows you the boot environments, select the normal boot Ubuntu Linux with the root on /dev/mapper/rootvg-lv_root.

7.5. Extend the LVM to use /dev/sda
Now we’re running on the LVM volumes on /dev/sdb, we want to reclaim the plain 0×83 Linux filesystem partitions off /dev/sda and add them to the rootvg volume group then extend each logical volume so it has a mirror on /dev/sda.

# delete /dev/sda2, /dev/sda3, /dev/sda4 partitions
# add /dev/sda2 as the remaining disk, toggle the partition
# type flags to 0xfd (Linux LVM)
fdisk /dev/sda

Now clear the first few blocks of /dev/sda2 since it will still have a Linux ext4 filesystem signature on it and we don’t want to confuse LVM.
dd if=/dev/zero of=/dev/sda2 count=100

Extend the volume group to include /dev/sda2 and add a mirror onto each logical volume.

# initialize the /dev/sda2 partition for LVM
pvcreate /dev/sda2
pvdisplay /dev/sda2
# extend the volume group to include /dev/sda2
vgextend rootvg /dev/sda2
vgdisplay -v
# now extend each logical volume to /dev/sda2
lvconvert -m1 --mirrorlog core /dev/rootvg/lv_root /dev/sda2
lvconvert -m1 --mirrorlog core /dev/rootvg/lv_swap /dev/sda2
lvconvert -m1 --mirrorlog core /dev/rootvg/lv_storage /dev/sda2

Let this run for a while, the system will be very busy syncing (re-silvering) the physical extents on /dev/sdb2 to /dev/sda2.

Side note: If something messes up and you need to remove the /dev/sda2 or /dev/sdb2 volume, or if you need to tear down the lvm2 setup (such as to remove or play around with RAID volumes), use

lvremove /dev/mapper/rootvg-lv_root
vgremove rootvg
pvremove /dev/sdb2

so you don’t have problems with residual signatures when you try to initialize the LVM volume group an physical devices again.

7.6. Update /boot on /dev/sdb

mount /dev/sdb1 /mnt/boot
cd /boot
find . -print | cpio -pvmd /mnt/boot
umount /mnt/boot

Now you should be able to boot off either /dev/sda or /dev/sdb.

8. Remaining issues
Despite turning off the screen saver, the HDMI to TV output dims occasionally and I’m pretty sure it’s not my Sony Bravia that’s doing it.

Audio is still a pain in the butt – I’m using the analog audio out on the Asus mainboard into a pair of Audio Engine speakers to get audio, since I think the HDMI driver needs to be changed to support audio over HDMI. I’m using the Open Source video driver instead of the nVidia and I think that’s the culprit. No time to test it right now though.

Update:
Tried out a LVM volume extend for the /storage filesystem:

df -h /storage
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/rootvg-lv_storage
669G 70G 565G 11% /storage

vgdisplay
— Volume group —
VG Name rootvg
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 11
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 2
Act PV 2
VG Size 1.36 TiB
PE Size 4.00 MiB
Total PE 357628
Alloc PE / Size 355728 / 1.36 TiB
Free PE / Size 1900 / 7.42 GiB
VG UUID JwB28k-Eeg6-HNq0-Ghdn-r4db-mNqd-fZWYfG

Since vgdisplay shows we have free space (7GB), issue the lvextend command:
lvextend -L +1G /dev/rootvg/lv_storage
Extending 2 mirror images.
Extending logical volume lv_storage to 679.78 GiB
Logical volume lv_storage successfully resized

After extending the logical volume, we can extend the filesystem. We will extend the fs while it’s mounted, since the current versions of resize2fs allow online extension or shrinkage.

resize2fs /dev/mapper/rootvg-lv_storage
resize2fs 1.41.14 (22-Dec-2010)
Filesystem at /dev/mapper/rootvg-lv_storage is mounted on /storage; on-line resizing required
old desc_blocks = 43, new_desc_blocks = 43
Performing an on-line resize of /dev/mapper/rootvg-lv_storage to 178200576 (4k) blocks.
The filesystem on /dev/mapper/rootvg-lv_storage is now 178200576 blocks long.

Yay! LVM sure makes fs and volume manipulation easy.

df -h /storage
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/rootvg-lv_storage
670G 70G 566G 11% /storage

Problem: I’ve done migrations of LVM2 volumes from 320GB SATA to 500GB SATA and added
a redundant 500GB SATA. Now I want to get software RAID 1 setup to protect the
root, swap and /storage filesystems from damage if/when one of the shiny new 500GB SATA
disks bite the dust.

Followed howtoforge.com linux_lvm_p1 (start of article) to free up sda from LVM
volume group VolGroup00 .. http://www.howtoforge.com/linux_lvm_p7

0. Did a file level backup to the fileserver:
[root@n59 20080724]# ssh root@192.168.1.2This e-mail address is being protected from spambots, you need JavaScript enabled to view it “tar cf – /lib” | dd of=mythtv-lib.tar
(repeat for /boot /storage /var /etc /home)

1. Free up sda2 LVM volume. I know this volume is not used anymore,
but it still has same-disk backup of /storage from when I was tweaking
MythTV.

[root@mythtv ~]# pvmove /dev/sda2
[root@mythtv ~]# vgreduce /dev/VolGroup00 /dev/sda2
[root@mythtv ~]# pvremove /dev/sda2

- now running on sdb only -

Setup RAID 1 mirroring (md)
–
2. Partition sda for mirroring (Auto RAID label)
[root@mythtv ~]# fdisk /dev/sda
<delete partitions>
<add primary 1 whole disk>
<set flag to fd – Auto RAID>

[root@mythtv ~]# fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 19 152586 83 Linux
/dev/sda2 20 60801 488231415 fd Linux raid autodetect

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 19 152586 83 Linux
/dev/sdb2 20 60801 488231415 8e Linux LVM

Notice that sdb is still using only LVM, not RAID.

3. Setup md devices – sdb is ‘missing’ – its still in use for LVM so ‘missing’
keyword is used.

[root@mythtv ~]# mdadm –create /dev/md0 –auto=yes -l 1 -n 2 /dev/sda2 missing
mdadm: array /dev/md0 started.

4. Prepare new md volume for LVM

[root@mythtv ~]# pvcreate /dev/md0
Physical volume “/dev/md0″ successfully created

5. Now extend the VolGroup00 vg to include the new md LVM volume

[root@mythtv ~]# vgextend VolGroup00 /dev/md0
Volume group “VolGroup00″ successfully extended

6. Now move data from /dev/sdb2 to LVM volume md0
[root@mythtv ~]# pvmove /dev/sdb2 /dev/md0

<long time>

7. Now we remove the sdb2 volume from LVM
[root@mythtv ~]# vgreduce VolGroup00 /dev/sdb2
[root@mythtv ~]# pvremove /dev/sdb2

8. Now we format /dev/sdb with fd (Linux RAID autodetect): (make it sdb1)
Same as sda.

9. Next add /dev/sdb2 to /dev/md0

[root@mythtv ~]# mdadm –manage /dev/md0 –add /dev/sdb2

10. Now the RAID array will be synchronized. This will take some time, you can check with

[root@mythtv ~]# cat /proc/mdstat

11. Update initrd BEFORE you reboot
If no /etc/mdadm.conf exists, you may choose to create it. It appears that I needed to
do that AND rebuild my initrd to support LVM on RAID1 during boot.

echo “DEVICE /dev/hd*[0-9] /dev/sd*[0-9]” > mdadm.conf
mdadm –detail –scan >> mdadm.conf

mkinitrd -f /boot/initrd-`uname -r`.img `uname -r`

12. Copy /boot over to sda – gets the new initrd (although /dev/sdb1 is still
labeled BOOT, so it is the partition that will be mounted as /boot)
[root@mythtv ~]# mke2fs /dev/sda1
mke2fs 1.40.2 (12-Jul-2007)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
38152 inodes, 152584 blocks
7629 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67371008
19 block groups
8192 blocks per group, 8192 fragments per group
2008 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729

Writing inode tables: done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 22 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.

[root@mythtv ~]# mkdir /tmp/newboot
[root@mythtv ~]# mount /dev/sda1 /tmp/newboot/
[root@mythtv ~]# cd /boot
[root@mythtv boot]# find . -print | cpio -pvmd /tmp/newboot
/tmp/newboot/./vmlinuz-2.6.22.4-65.fc7
/tmp/newboot/./config-2.6.22.4-65.fc7
/tmp/newboot/./initrd-2.6.21-1.3194.fc7.img
/tmp/newboot/./System.map-2.6.21-1.3194.fc7
/tmp/newboot/./initrd-2.6.22.4-65.fc7.img
/tmp/newboot/./System.map-2.6.22.4-65.fc7
/tmp/newboot/./lost+found
/tmp/newboot/./grub
/tmp/newboot/./grub/device.map.old
/tmp/newboot/./grub/jfs_stage1_5
/tmp/newboot/./grub/device.map
/tmp/newboot/./grub/ufs2_stage1_5
/tmp/newboot/./grub/e2fs_stage1_5
/tmp/newboot/./grub/xfs_stage1_5
/tmp/newboot/./grub/stage2
/tmp/newboot/./grub/splash.xpm.gz
/tmp/newboot/./grub/grub.conf
/tmp/newboot/./grub/fat_stage1_5
/tmp/newboot/./grub/vstafs_stage1_5
/tmp/newboot/./grub/grub.conf.dist
/tmp/newboot/./grub/stage1
/tmp/newboot/./grub/menu.lst
/tmp/newboot/./grub/reiserfs_stage1_5
/tmp/newboot/./grub/iso9660_stage1_5
/tmp/newboot/./grub/minix_stage1_5
/tmp/newboot/./grub/ffs_stage1_5
/tmp/newboot/./config-2.6.21-1.3194.fc7
/tmp/newboot/./vmlinuz-2.6.21-1.3194.fc7
25716 blocks
[root@mythtv boot]# cd /
[root@mythtv /]# umount /tmp/newboot

13. If you’ve mucked around with the hd ordering in grub, undo it now:
Grub configuration:
# grub
grub> device (hd0) /dev/sda
grub> device (hd1) /dev/sdb
grub> root (hd0,0)
grub> setup (hd0)

14. Reinstall grub to ensure initrd references in grub are updated
[root@mythtv ~]# /sbin/grub-install /dev/sda
[root@mythtv ~]# /sbin/grub-install /dev/sdb

NOTE: I haven’t taken this to the fall back filesystems or having the
/boot filesystem on a RAID1 volume yet, but one should be able to enable
RAID1 for /boot now (create md1 == /dev/sda1 and /dev/sdb1 and setup an ext2 fs
on md1 to hold the RAID1 protected /boot fs). Haven’t tested
that yet, but did get that to work in earlier 2.6.x kernels (Debian and Fedora).

15. Hold breath, have Fedora Core 7 Rescue disk ready, Reboot

16. Celebrate.