# Tivo Restore failed: Premature end of backup data then kernel problems



## philt (Oct 25, 2007)

Hi, I'm new around here - I hope this doesn't come across as yet another newbie messed up his Tivo thread ...appologies...

Several years ago I upgraded my tivo to 120G; I have a feeling I had a problem with making a backup then and ended up directly copying the contents of the old drive to the new drive. Anyway my 120G drive has been faulting a little and I got a GSOD which thankfully disappeared on switching off and on again so I decided my HD was on the way out and I'd replace it, taking a backup at the same time. This I duely did and tivo.bak was produced by MFSLBA48.iso. The problem has come when I try to restore, I got "Restore failed: Premature end of backup data" on the linux screen. All I can find on the web suggests this is because I have expanded twice however I'm following instructions on Steve Conrads pages - he has done exactly the same ie 40 to 120 to 250 (which is the size of my new Seagate DB35 drive) without problem.

I am writing in case you can give me any pointers, note I still have my original 40G drive (which did some time back in Tivo) but really wanted the uptodate season pass info from my (?failing) 120G drive to be on my new drive. In my desperation I also typed in copyKernel so could that have made things even worse.

....2 months later...

The above was an e-mail I prepared a month or two ago but never got an answer from the people I sent it to (I should have sent it to this e-mail list). Since then I went for it and copied the COMPLETE contents of my (?failing) 120G disc to my 250G disc (which I think I had already run copy kernel on (possibly twice)) using a command line with tao in it (I think it was mfsbackup -Tao - /dev/hdc | mfsrestore -r 4 -s 127 -xzpi - /dev/had). After about 18hrs of copying, it showed my disksize as 250G so I was hopeful. I also installed cachecard drivers via the Knoppix boot disk in readiness for buying a cachecard (which, 2 months later has just arrived and Im going to install this morning).

The installation initially seemed to work ok (except error: driver failed to load and error: no information in kernel log message on Tivo bootup, presumably due to cachecard drivers but no cachecard) however it became increasingly apparent there were intermittent problems and I think they are getting worse: 1) programmes will suddenly slip into another tv programme completely, 2) (sometimes associated with 1) at a certain (reproducible) point in a recording Tivo will reboot, 3)recordings (often ones which previously have been viewable) will state Error playing a recording and be unavailable. Do these problems fit with a dunce bodging up a tivo upgrade??! Or previous hard drive errors? Is there a programme that stands a chance of fixing such errors? Im not bothered about having 250 versus 120G so is there a way of reverting to a non-LBA48kernel (bear in mind I dont know what Im talking about with Linux)? Why couldnt I restore my original back-up (both this time and in my original 40-120G upgrade? Is my tivo.bak file going to be of any use either now or if massive crisis strikes and is it worth me sending it to anyone to examine?

Sorry to barrage you with questions, I HAVE looked up a lot of this online but dont seem to find a scenario that fully equates to my current one!

Phil 
Staffordshire Moorlands


----------



## ColinYounger (Aug 9, 2006)

Phil - no newbie questions there. Most of them look distinctly non-newbie. 

First - I am no expert on drive recovery, etc. There are experts floating around who I expect will jump in. But in the interests of being friendly and giving a response...

1) I expect your copy of the 120 -> 250 copied across all the bits that were failing. The symptoms you describe sound like corruption in the MFS (TiVo's database) which you've copied across and possibly exacerbated.

1a) Having said that, it might be an incorrect swap file but my bets are with 1).

2) With 1 in mind, I think your solution will be to say bye bye to the drive contents and re-image it. If you haven't got a 'pure' drive image, there's a begging thread here - note that it only supplies the 2.5.5 software; if your TiVo is running 2.5.5a you'll need extra bits and bobs - check your system information on TiVo to see. Your 40Mb drive might be your saviour!

3) LBA48 kernal just allows TiVo to access larger drives. It does not cause problems of any kind (to my knowledge) and can be applied as many times as you like. In short, IMO LBA48 is a red herring.

4) I'm not an expert, but yes; I think your original backup is duff. I don't know why.

HTH, and hopefully Blindlemon or Healydave will jump in.


----------



## blindlemon (May 12, 2002)

It sounds like maybe you are NOT running with the LBA48 kernel.

After a reboot, check the kernel log. There will be a line similar to the following that tells you the kernel version:-

```
Jan 1 00:00:16 (none) kernel: Linux version 2.1.24-TiVo-2.5 ([email protected]) (gcc version 2.8.1) #14 Wed Oct 8 12:06:25 MDT 2003
```
If it is as above then you *do* have the LBA48 kernel.

If you don't have that line but one that mentions '[email protected]' instead then just pull the drive, boot from the LBA48 CD and re-run copykern choosing kernel option 1 to install the LBA48 kernel and initialise the swap. Any corrupted recordings already on the drive will remain corrupt and should be deleted, but future recordings should be fine.


----------



## philt (Oct 25, 2007)

Colin and Blindlemon - many thanks - i have just looked up how to check the kernel via backdoor (haven't backdoored before) - now I have the most technical bit - persuading my wife to stop watching telly! I fitted cachecard ok but a) can't telnet or ftp (wants to but asks for password or something - Windows Vista command prompt) and it also looks as if I have the "classic MSP chip not initalizing properly" problem (won't let me insert URL as I'm too new) brought on by fitting the cachecard. Life's never simple - I'll raise these issues as another thread if I can't find the answer elsewhere (hopefully unlikely). Will get back to you, Phil.


----------



## philt (Oct 25, 2007)

wife off telly / tivo, backdoored and surprise surprise there's [email protected] just below Swansea University Computer Society in log! So I don't know what happened to my copykernel command(s) 2 months ago although I'm not sure I remember being offered number options with it; will pull drive over next week, Phil.


----------



## blindlemon (May 12, 2002)

Do it ASAP - every time the old kernel tries to write past 137gb it will wrap around and write to some other part of the drive instead. The danger is that it may overwrite something important.


----------



## philt (Oct 25, 2007)

will do - does this mean I've been incredibly lucky over the last 2 months; also, why if my kernel hasn't updated, does tivo still show recording capacity as the full 250G 85hrs at best quality?


----------



## blindlemon (May 12, 2002)

Yes you have been lucky. 

Although the wrap-around wouldn't have occurred until the OS needed to write past 137gb, the fact that the addressing of the drive is sector-based at that level means that bad writes can occur in any of the partitions on the drive - including the OS, the boot partition and the swap. Therefore any write 'past' 137gb could effectively be the one that clobbers something important. 

The recording capacity shown is based on the size of the MFS partitions which will be correctly created if you did your upgrade with a LBA48-aware boot CD. The kernel on the boot CD can 'see' and access the area past 137gb correctly and writes the partition data accordingly - it's just the TiVo kernel that messes up.

If I had aTiVo with a drive > 137gb, no LBA48 kernel and anything I wanted to preserve on it, I'd switch it off immediately and not use it again until I had installed the LBA48 kernel.


----------



## philt (Oct 25, 2007)

thanks blindlemon - somewhat sobering - probably saved by my wife's desire to clean unwanted programmes off the disk whenever she can (which sometimes makes me wonder why I'd upgraded at all! ...but useful post holidays) - will sort today!


----------



## ColinYounger (Aug 9, 2006)

Glad my 'LBA48 is a red herring' was spot on, then. 

</sarcasm>

That'll teach me to jump on a thread where I don't know the in's and out's. <sigh>


----------



## philt (Oct 25, 2007)

all sorted - many thanks for all your help everyone; only probelem now is that I keep losing sound cos I've been stupid enough to buy a secondhand v2.0 (I think) Cachecard! which I presume is impossible to get upgraded to v2.2...
Phil.


----------



## mikeyp (Dec 22, 2005)

I'm not sure any more, but I believe you can send it back to be re-flashed to v2.2 but you'll be without it for a good while as it ships across the atlantic and back.
9th tee are the main sellers, so if you email them I'm sure they can tell you what you need to know.
http://www.9thtee.com/tivocachecard.htm


----------

