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PVRs, file transfers, large hard disk drives and odd filesystems…

Posted in technology, TV with tags , , , , , , , , , , , , on January 27, 2014 by bytor

OK this is a somewhat minority interest post, but it might help someone who is trying to do the same tasks as I was, or experiences some or all of the same difficulties.

First some keywords for the search engines: PVR, ext2, ext3, linux, FAT16, FAT32, FAT16/32

OK first up: what was I trying to do:

  • transfer files from my PVR (personal video recorder, a Humax Foxsat HDR) to my Windows 7 PC, for the purposes of archiving, and converting to compressed MP4 files using Handbrake, for playing on my tablet (a 1st generation Google Nexus 7)

Humax FoxSAT HDR

Problems:

  • Some files are too large to be transferred. Previously I was using a portable external drive of about 30GB size, which in actual fact was a repurposed iRiver MP3 player (iHP140) which I had long ago installed some 3rd party firmware (Rockbox) to extend its functionality, and subsequently stopped using when I got a smartphone that doubled as a portable music player.
  • iRiver iHP140
  • This device could be mounted as a USB drive, and I believe it was formatted in FAT 16 or FAT32. This has a filesize limit of 4GB and some of the uncompressed video files (for exampla a movie longer than about 2 1/2 hours) would exceed this limit.
  • The iRiver was getting a bit flaky and I suspect, recahing the end of its reliable natural life. Sometimes it would not be recognized, or files would randomly disappear, then reappear when it was powered down, rested, and remounted.

Initial solution seemed simple. External hard disks these days are larger, cheaper (and one hopes) more reliable. PC World had a good deal on Western Digital 1TB “My Passport” small external drives for £60. I snapped one up.

western_digital_my_passport_ultra_1tb_blue

First problem encountered. The Western Digital HDD was formatted in NTFS. This was not recognized by my Humax PVR. Since there is no chance to alter the Humax, my options were limited. It recognizes either FAT 16/32, or linux EXT3. So if I was to continue my plan I would have to reformat the WD HDD to one of these. But which?

FAT 16/32 has the advantage of very wide compatibilty. Windows of all flavours would read it, and so would the Humax. But it is somewhat ill suited to the large size of modern HDDs. On Windows you can format a drive in FAT32 but with some severe limitations. The first is that maximum volume size if a meagre 32GB. Not very useful if your drive capacity is 1TB! Yyou can use one of many 3rd party partition manager programs to format a FAT32 drive with a larger volume size than this, but then you also come across other potential problems: cluster size, file allocation table size and performance. Now I don’t pretend to really understand the intricacies of this sort of stuff but some more info on this is here.

Anyway, I read enough to decide that maybe formatting to FAT16 or FAT32 was not likely to be the best use of my new 1TB drive, so I decided to investigate formatting in EXT3. Now what is EXT3? I knew that it was one of the commonly used filesystems in many Linux systems, but apart from that I was ignorant. I soon discovered that Windows doesn’t read this filesystem natively, and this was going to be a major problem in my original task of transferring files from the PVR to the Windows PC.

However a quick search revealed that there were a number of ways to allow Windows to access, at least on a read-only basis, EXT filesystems.  The EXT2fsd project seemed to be one of the one that came up most frequently in searches. However I was made a bit wary by the fact that it doesn’t seemed to have been updated since 2011, and also many webpages mentioned its risk of data corruption and other teething troubles. It sounded like a possible solution, but not perhaps ideal.

Finally I settled on another solution that sounded a little more stable and also seemed to allow writing a Windows system to a EXT3 system – Paragon Software EXTfs for Windows.

I downloaded this and installed it easily on my Windows PC. I then downloaded a ISO CD ROM image of a linux partition manager software called GParted. This worked very well and I was able to boot to Linux and using Gparted, formatted the Western Digital HDD to EXT3. I thought it might take a very long time on account of the large size of the drive, but actually it only took 11 minutes. Then I mounted it using the Paragon EXTfs software and it was recognized straight away. It appeared in Windows Explorer just like any other drive.

This is easy! I did a quick test file transfer of a small file from Windows to WD without problems. Next up I deleted all the files to start from a blank slate and connected the WD to my Humax. Recognized! Success! I straight away transferred one of the files that had been too large for my old iRiver. No problems there. Connected back up to the Windows PC and transferred said file to the laptop. All my problems are solved. (Or so I thought).

The Sting In The Tail

I was about to have some annual leave, and one of my ideas was to catch up on some TV that I had been missing recently. I transferred a large amount of video and audio files to the WD drive. I checked them on the Windows PC using the Paragon extfs driver. Then I relocated to where I was spending my leave (where there is another Windows PC and a different PVR, this time a Humax Freeview FOX-T2 HDR – note this is different model from the PVR I have at home which is a Freesat one.)

humax hdr fox t2-580-100

First thing I wanted to do was watch one of the files I had transported on the WD HDD, but on my Nexus tablet. I installed Paragon extfs on the PC in my new location and transferred the file there. Then I transferred to my Nexus without problems.

Now came my big mistake. I discovered that the 2nd Humax PVR (the Freeview one) had a recording that I wanted to keep. I thought I could simply connect the newly EXT3 formatted external drive to it, copy the file onto it, then onto the Windows PC to shrink using Handbrake, then onto my Nexus or just keep on the external drive until I got back home in a week. After all I wasn’t pushed for space on this 1TB drive.

However, when I connected it to the Freeview PVR and browsed to the drive, I was a bit surprised to find it appeared “empty” instead of the dozen or so files that I had just looked at a few minutes before. I thought it was a bit odd, but continued to copy the file from the Freeview PVR onto the WD HDD.

When I connected it to the Windows PC and viewed it using Paragon extfs I was alarmed to see that now all those files that I thought were safely stored on the external drive, were GONE! In their place was the newly transferred file from the Freeview PVR, and a small collection of files that I had previously transferred from my other PVR a couple of days ago, but subsequently erased (or so I thought).

It soon dawned on me that somehow, by connecting the external EXT3 formatted drive to the second PVR I had caused the old files to reappear and newer ones to “disappear”. Don’t ask me the technicalities of what had happened. Some linux guru might be able to explain. However I suspected that they might still be accessible and recoverable…. somehow. I had only written one time to the drive (the transfer from the second PVR), so I thought there was a fair chance most of the data would sti8ll be intact.

I searched for file recovery/undelete software. This needed to work on EXT partitions, but run from Windows, so this narrowed it down a bit. To cut a long story short, I tried a few. DiskInternals have a piece of software called Linux Reader which I thought might fit the bill. However after installation it seemed to take an exceedingly long time to read the drives. Eventually I gave up and searched again. Next I tried EaseUS Data recovery Wizard. This actually did work in that it did eventually (after a good many hours in the background) read and index all the files on the WD external drive, including all the ones that had “disappeared” and which I wanted to recover. BUT, when I tried to recover them I found to my dismay that the free trial version only allowed you to view and search but to actually recover the files you had to buy the “pro” version for $80.

Finally, I tried a free piece of software from RTT (R-Tools Technology, @RTT-inc on Twitter) called R-Linux. This looked like it was going to take an unrealistic time to scan my 1TB drive (the “time remaining” indicator went up to 5 days!) but it actually completed the scan in about an hour. After that I was successfully able to recover (and transfer intact to a Windows folder) most of the files I had lost. A few were incomplete, probably as a result of some disk writing on the second PVR but I was able to get most of what I wanted and it didn’t take too long.

So, the moral of the story is that ext3 formatted drives still don’t play perfectly with Windows systems, but probably using Paragon’s extfs for Windows software is your best bet. Be careful and you should be OK. Don’t mix and match the systems you connect the drive to any more than you have too, and back up frequently (always a good idea in any computer related activity). Finally if you get into a pickle, RTT’s R-Linux is a saviour.