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The Sagem PVR 6280T has left the building

It has been replaced by a Humax PVR-9200T. The Sagem box had a number of peculiarities that have never been fixed by Sagem even though it has had a couple OTA (Over The Air) upgrades. When I got close to its 1-year anniversary I had actually decided to see what Tesco would say if I tried to return it under warranty, but buying and moving house at the same time meant that I never got around to it. Its worst peculiarity happened if you were viewing a recording and a new timed recording kicked in. It would briefly switch to the channel on which the recording was about to take place, stay there for a few seconds and then return to what you had been watching all along. But even though its peculiarities were really annoying at times, its ultimate downfall in this household was the size of its hard disk. The fact that we don’t actually se that much TV means that the hard disk was usually more than 75% full because of recordings we wanted to see sometime.

The Humax has a 160 GB hard disk, so it should in theory make life easier for us. It is of course a possibility that all that happens is that it will take us longer to get to the 75% mark and then we will be back where we started. If that happens, I plan on using the USB plug and take some of the recordings of it.

So what is there to like or dislike about the Humax device compared to the Sagem box (some of these features are not unique to the Humax, but they are features the Sagem didn’t have):

• If something I want to record is part of a series, and I choose to record, it asks if I want the whole series or just that particular program.
• Rather just having the ability to choose to record from the EPG or via date-and-time programming, there is a “Find” option where I can search by name or part of the name or I can choose a genre such as “Movies” or “Education” and scroll through the resulting list. After I discovered that, I haven’t used the EPG list at all.
• I like and dislike the remote. It is much bigger than the remote for the Sagem, and most of the buttons are much better laid out. On the Sagem I frequently pressed the wrong button. Unfortunately, some of the potentially useful buttons are under a sliding panel which doesn’t seem that sturdy, and I just don’t use them because they are under that panel.
• The Humax can make two recordings simultaneously. Even though the Sagem box has twin tuners, it can’t make more than one recording at a time.
• If I choose to record something which conflicts with something else I’ve already set to record, the Humax will show me the conflicting recordings, and I can choose to replace or leave alone. On the Sagem, it would just ignore you.
• The EPG take ages to fill with data compared to the Sagem. I knew about this from comments on the internet, so it wasn’t a surprise. The other features of the Humax outweigh this downfall, but it really does take a surprisingly long time to fill up.
• Getting to the list of available recordings was actually better on the Sagem. One click on the “List” button would bring, well, the list of recordings up where you could see all details of the recordings such as date and time the recording was made, from which channel etc. Highlighting one of the recordings and clicking “Ok” would start the playback. The closest thing to this simplicity on the Humax involves pressing one of the buttons hidden underneath the sliding panel, and the list that pops up is not very detailed in information. If you want the detailed information, you have to press “Menu” and then choose “Recordings” to get to a list with information similar to that displayed on the Sagem. When you then select a recording, it starts playing right away, but the menu interface is still on the screen as well, so you have to push the “Exit” button on the remote to get the menu interface away.
• There is an 8 GB partition on the hard disk which is reserved for JPEG pictures and/or MP3 audio files. Whether you use it or not, it is there and taking up exactly 8 GB of space. If you do use it, for many people 8 GB would turn out to not be enough, and for those who don’t use it, it is just wasting space.

At the time of writing, the cheapest place to get the Humax is at Dixons where you can get it for £159.94 (incl. shipping). They are frequently sold out at Dixons, so you’ll have to watch their website every now and then to check whether they are back in stock. Or you can buy my used Sagem box on eBay…

More on Converting RAID-1 to RAID-5 with no data loss

I have for a while had a RAID-1 disk array on my Linux based (Centos 5) home server. As I was beginning to run out of disk space, I wanted to add an extra disk and change it to a RAID-5 disk array thereby doubling the amount of disk space available.

My Dell PowerEdge 930 has a drive bay with room for 4 hard drives. The server originally came with a Western Digital 80 GB SATA drive. This contains everything, except for /home. 2 Maxtor DiamondMax 10 300 GB drives were originally setup in a software RAID-1 array. So to get that extra disk space, I bought a new hard disk that I wanted to add to the server and then turn the RAID-1 array into a RAID-5 array,
I was going to do it the hard way, take a backup, wipe away the old array, create a new one and restore the data. But I found a blog entry here that explains how to change it online. So this blog entry is first of all to tell anyone interested that it actually works, but also to document those steps that weren’t entirely clear (to me at least). It was quite some time ago that I created the original software RAID array on the server, so there were a few additional steps necessary that are not documented in the above. You need to follow the instructions in Scotts document, and you can then refer to my document in case you run into some of the same issues I did.

My home server hosts a couple of web sites, a mail server + several home services such as being a file server for, downtime had to be minimised which is why the in-place conversion appealed so much to me. I was even braver than Scott and except for a few actions where I stopped some services and then started them again shortly after when everything seemed all right, all services were active throughout the conversion

Stopping the RAID array
My server has no keyboard or monitor attached, so I was going to do this via ssh. That was only possible because I wasn’t touching the boot drive. If you want to do this with the boot drive, you need a real screen and keyboard attached and do what you are doing there. The mdadm –stop command would not stop the array and it took me a while to realise I had forgotten to umount the array. I couldn’t do that either, I kept being told that the device was in use or busy. The lsof command
lsof |grep /home
finally showed me the issue. I had logged in as a normal user and then issued the su command, so /home/users was in use. I needed to login directly as root.

New partition on new disk
The disks I originally purchased are no longer in production, and the new disk of course doesn’t have the same size as the original disks. Some Linux RAID documentation seems to imply that it doesn’t matter if the partitions are of different size, whilst other documents said that you would lose data if the partitions were not of the same size. I wasn’t going to experiment, so I made the partition on the new disk the exact same size as the partitions on the old disks. The simplest way to get a partition on the new disk to be similar to the partitions on the old disk is to use the sfdisk command which on my server meant I did
sfdisk -d /dev/sdb | sfdisk /dev/sdd

Re-shape process
Doing “cat /proc/mdstat” gives you statistics about the data transfer speed and the number of minutes it will take. The value for the data transfer speed was fairly consistently around 4000 KB/sec and it claimed it would ~1100 minutes. I tried speeding it up by manipulating the values for:
/proc/sys/dev/raid/speed_limit_min
/proc/sys/dev/raid/speed_limit_max
It didn’t seem to make any difference so I finally left it and went to bed. Next morning when I woke up it was finished reshaping, and I did not sleep for that long. As you can see from the graph, at some stage, it picked up speed and raced through the rest of the reshaping.

Resizing the array
Reading various RAID documentation makes it clear that there is an optimum “stride” value which is equal to the chunk size divided by the block size. In my case the chunk size is 64 KB and the block size is 4 KB, so the stride value should be 16. You can find the block size with
dumpe2fs –h /dev/md0
and the chunk size with
cat /proc/mdstat
The man pages for resize2fs “will heuristically determine the RAID stride that was specified when the file system was created”. I have no idea whether that means that it will pick the optimum stride value, so I chose to specify the value manually, so on my system I did
resize2fs –p –S 16 /dev/md0
By doing a du with one minute in between, I could see that the resize was happening at about 16 GB/min.

Summrary: It works, I had minimal downtime, and I essentially had two sets of data to operate on. The data on the array being converted and the data on the backup.

Dnsmasq

I’ve installed dnsmasq on my Linux server (Centos 5.1) and stopped BIND and dhcpd. I checked prior to stopping them, and BIND was taking up ~200 MB RAM. I run a mail server (Postfix) so the large amount of RAM used by BIND is probably due to all the DNS look-ups it has to perform. I will be interested in seeing how much RAM I now use.

Configuration was quite easy, certainly a lot easier than BIND and dhcpd. I did hit two challenges:

I started accepting lots of email for a domain that I do host a website for, but I don’t run email services for it. So it was never in my local named files, but I did include it in the /etc/hosts file which is where dnsmasq reads the dns names and ip addresses from. So I removed it from the hosts file and the email was still being accepted. When it couldn’t find the host, it sent a request to the upstream dns servers. That was solved by adding the parameter “local=/domain.tld” (with “domain.tld” being replaced with the domain name I use on the internal network).

I noticed a “log-queries” command which is supposed to log each DNS query. I was curious as to what that would look like, so I enabled it. Only, nothing happened. Strange, as the “log-dhcp” command worked fine. Eventually I found a reference in a mailing list somewhere that your syslog facility must be in debug mode, and it does mention that in the sample log file, but as the log-dhcp command worked without that, I had paid no attention to it.

Winamp, FLAC and media players

In earlier posts, I have mentioned switching to using Winamp as my main PC-based music player and deleting all my MP3 files and re-ripping my CD’s in the FLAC format. I have not regretted those two decisions. Having all my audio in a loss-less format means I can switch to another format at any time without losing anything other than what the other format loses. So if I convert from FLAC to another loss-less format at a later time, at least I won’t have to rip all the CD’s again. I still like Winamps media library and the ease with which you can create new “views” is great.

In the original post about ripping all files to FLAC, I did worry a little bit about the iPods and other MP3 players sprinkled throughout the home.

That challenge turned out to be a non-issue. Winamp supports “Plays for Sure” devices like the iRiver as well as iPods and it is quite simple to configure it to convert non-supported file-formats into another supported format on the fly as the files are transferred to the MP3 player (transcoding). So the PC’s used by those family members with iPods use Winamp to automatically transfer whatever audio we want whilst on the fly convert the FLAC files to AAC, and the lone iRiver has audio files converted on the fly to MP3. It obviously takes longer than transferring files that might already be in a format supported by the relevant media player.

Winamp does have “out-of-the-box” support for iPods, but I have installed ml_ipod which has enhanced iPod support. For example it can transfer cover art onto the iPod if it is present on the server.

What has not worked so well is getting the D-link DSM-320 media player to play. The version of TwonkyMedia I have is supposed to (like Winamp) be able to transcode from FLAC to another format, but I haven’t had that work reliably.

I’ve played around with TVersity which was somewhat better, but still not that reliable when transcoding. Unfortunately it is a Windows program and the home server runs Linux. I tried installing TVersity in a VMware image where the OS was Windows. That image works fine when the VMware image runs on Windows host. I installed the VMware player on the Linux server. The Windows image with TVersity seems to run fine, but the D-Link media player can’t locate it. It is most likely a routing issue. The Linux server probably needs to be configured to forward multicast (which uPnP uses, and the D-Link media player uses uPnP). I’ve tried to configure the forwarding of multicast, but without success. So at the moment the D-Link media player is idle.

I have considered buying the Netgear EVA8000 which on paper looks like it does most of what I want from a media player. There are seemingly many things to like about it, but specifically it supports FLAC files natively, and it can get access to files on any fileserver supporting SMB (which a Linux machine with Samba does), so there would be no need for either TVersity or Twonkymedia. So why haven’t I rushed out to buy it? Too many comments from existing owners about things that don’t work well, and the price is a bit high. For not much more I can buy something like the AOpen miniPC.

Linksys WAG300N

My ADSL modem died on me on recently. For two months my BT supplied ADSL connection had become worse and worse. The modem was loosing the signal several times a day. The statistics page of the X-Modem M3 from ADSL Nation seemed to imply that it was the ADSL connection. I even had BT check the line and they suggested lowering the line speed. And then I lost the connection again and the modem couldn’t connect again. I finally got suspicious and tried the USB ADSL modem I was originally supplied with, and guess what, no problems with the ADSL line at all.

So this time I bought a combined router, switch, access point and ADSL modem. I don’t really like that combination, I prefer the ADSL modem to be separate, but the X-Modem M3 is the only true Ethernet ADSL modem available for the UK market (as far as I know). I decided to go for a device with 802.11n (draft).
I once had a Netgear ISDN router; firmware updates ended very quickly and support was not good. I bought a Linksys WRT54G some years ago and it just keeps working and working, and even though Linksys seems to have end-of-lifed it as far as firmware updates go, the firmware updates did continue for quite some time. So I chose the Linksys WAG300N.

I’m afraid it will be returned though. It has performed well, but:
It has an On/Off button. The other day there was a short power cut and the WAG300N did not switch back on by itself, I had to press the on/off button when power had come back on. I run several services on a home server (which comes back on automatically after a power cut), so the ADSL modem has to come back on its own after a power cut as well.
There are no ADSL statistics. You could argue that the ADSL statistics are of little use as I couldn’t use them to figure out what was wrong with the deceased ADSL modem, but at least I could see that something was wrong. So I want some statistics.

On the positive side: It was extremely easy to get working with the ADSL connection, and one big plus point with me is that it supports SNMP out of the box.