Tuesday, October 20, 2009

One shed or several sheds - DVDram

The title needs a bit of explaining and I do that next.
( If you want to skip straight to the factual bits then skip down a page now. )


When it comes to how you organise your storage, people like to do things in different ways. I use a physical scenario to aid this introduction to DVDram.

(DVDram is how I refer to things in this article, as visually it seems to stand out and it is unlikely to be confused with the more widespread dvd standards you already own perhaps)

You live with a partner and have a large back garden area, and your partner says hey you can have half of that space out back and make some storage for yourself - they have some great wooden sheds down at the DIY place how about it?

I'm just going to give some dimensions to add a bit of realism here - so the area you can have is 10 metres by 20 meters with free access on both of the longer sides.

Question: Do you go for one single shed or several sheds?

You price things up and it turns out that you can cover that whole area with one single shed for £900 or alternatively 3 individual sheds for 3 * £300 = £900.

So pricing there is no difference, it really is a case of personal preference.

Here is where your experience comes in...
  1. Are you the type to break up a storage closet into shelves?
  2. Do you prefer to spend less time organising up front and are happy to trawl through your boxes later on?
Where DVDram wins, for my mind, is if you answered YES for (1) and NO for (2) and I make some bullet points here:
  • Appendable without having to erase what is already on the disk.
    [ CDRW multi-session achieved this but some find it a bit of a pain ]
  • An alternative to having a box full of 4gig usb sticks
    [ A whole bunch of 4gig usb sticks might have quicker writes but have you tried writing readable labels on something so small? ]
  • An alternative to a single huge hard drive for backups (if you prefer the hard drive way then you might have answered NO for (1) above)
Drawbacks of DVDram:
  • Best suited to write a lot, append a bit sort of data*
  • Great for offline storage for things that are genuine snapshots but only consulted in dire emergencies.
*I give an example next to illustrate what I mean by write a lot, append a bit.

I have a 2 Gigabyte Audio Player...


...and as with all flash solid state memory, it will stop working at some point.

"Backup your work, backup your life!"

...are what we hear and so several times a year I have been taking a snapshot of this drive in tar form or as squashfs.

And so each time I visit Amazon for some mp3 songs, if I then took another snapshot this would be overkill. But the new songs should be appended somehow.

Howto:
  1. --append option of tar will do the trick
  2. Create a new squashfs (seems a bit wasteful to do this but okay for irregular full snapshots approach to backing up).
  3. DVDram
  4. USB key (if you insist)
  5. I have a super huge X Terrabyte hard drive so who cares.
    (you may not have answered YES for (1) and NO for (2) in the wee test)
So, going the DVDram way, is there anything you should know? Well firstly it is going to take 20 to 30 minutes to write 2 Gigabytes when you first use a blank DVDram.

The 20 minutes it takes is why I was particular in saying I use it for 'write a lot, append a bit' earlier.

So having backed up my Audio Player once, I just keep appending the new stuff (using drag and drop if you like).

Adding new songs to my backup is really quick and no hassle (Unlike regular DVD rewriteables I have no need to erase each time)

Takes about a minute to write 50 megabytes of new songs in my experience.

Here are some thing that I was most surprised about regarding DVDram:
  • Not only is a DVDram drive affordable, but lots of you already have one without realising! A modern SATA dvd writer will often also read and write DVDram.
  • The discs are the same prices as rewriteables so you will likely get change from 2 whatevers (insert your currency here)
If your still wondering about the cost of a DVDram drive after reading the above, then just to clarify - I just purchased a Samsung SATA DVD writer for £25 in UK and it does the job just fine.

Q&A:
  • Does the disk spin constantly? NO. When you are using the data on it it will spin (as would a hard drive).
  • But surely a DVDram drive is expensive? About the price of a glass of beer.
  • The spinup time for DVDram must be an age? Err no, 4 seconds here.
  • You cannot drag and drop onto it? Yes you can. I use Thunar - it's good to go.

Footnotes and further reading:

If you are interested in Amazon Drmless mp3 and are running Debian 5 or newer then there are some instructions here on how to proceed. In short you would need to get amazonmp3.deb from Amazon and ensure you have some libboost stuff also.

DVDram uses the UDF filesystem so has no issues with huge files (over 2 Gigabytes) whereas regular DVD media would likely autoswitch from iso9660 to UDF in that instance.

The optical drive in your laptop may well read DVDram okay. Mine is a Dell Inspiron 1525 bought in 2008 and it works great. Dell made no mention of it in the specification I think. The laptop is an N model and came with Ubuntu preinstalled.
[ Drive was identified by K3b as TSSTcorp DVD+-RW TS-L632H (details here) ]

The optical drive in your laptop may well not be any good at writing DVDram. Some manufacturers may not have taken the trouble to enable the DVDram feature, even though the drive is perfectly capable.

Comments welcome. If you are already a firm fan of your current backup system then stick with it. After all if it works then that's great.

If you have TSSTcorp TS-L632H but cannot get it to read DVDram then perhaps you might try either or both of the following:
  • Use 3x speed Traxdata DVDram 4.7gb single sided (120 minute) disc
    (Then you would be using the same disc I tested with)
  • If you are not already using Ubuntu or Debian then try a live disc with "Make no changes to my computer" startup option, and see if you get a better result whilst running live disc.

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