AOA Forums AOA Forums AOA Forums Folding For Team 45 AOA Files Home Front Page Become an AOA Subscriber! UserCP Calendar Memberlist FAQ Search Forum Home


Go Back   AOA Forums > Hardware > General Hardware Discussion

General Hardware Discussion Hard drives, CD, DVD Monitors, All hardware questions not better served by our other Topics


Reply
 
LinkBack Thread Tools Rate Thread
  #1 (permalink)  
Old 11th August, 2004, 06:18 AM
DimViesel's Avatar
Member
 
Join Date: April 2003
Location: Earth
Posts: 517

Arrow THE DVDRAM, DVD-RAM : 'What is it?' THREAD -PLS HELP

What I know:
It is a std. of rewriteable storage which allows RAM store to a CD sized disc of DVD like capacities. It is based on an entirely different technology & format to DVD writing be it + or dash DVD format writing.
The media tends to be multilayered writing surface & the 'grooves' are not concentric circles but some sort of wave pattern as they progress along the disc(?).

There are type 4 & type 2 discs.
'Type4' discs differ from 'Type2' in that the disc can be removed from its cartridge to be written to on multiformat DVD writing drives capable of supporting DVDRAM discs.

If the disc is never removed from its 'cartridge' or housing, then it guaranteed data-safe to a million write operations, similar to the claim made on the reliability of minidisc media I believe.
DVDRAM although arguably the most reliable & secure means of backing up data in an ongoing manner failed to find wide adoption in europe due to its cost & the incompatibility presented by its cartridge.
It is used widely in Japanese domestic video recorders since it allows a data stream to be written at the same time as one is being played (due to its RAM like behaviour - it is like working with a HD volume in this respect).

I cannot buy a drive that writes to discs inside the cartridge any more as all modern DVD drives that support DVDRAM require the disc to be placed on the tray outside of its cart.

This are the crucial questions:
Can I get hold of a drive that accepts media in their cartridges?
What is the fastest DVDRAM media & what capacity / density is it available in?

Is there a source of information or a forum where people are more likely to have answers to this kind of question?

Remember:
your apt answers, will change the couse of history & the perception of reliable storage as we know it..

Thank you.
__________________
Searched near & far across networked lands for a sig. that would do.
I searched thorough, & wide, for a signature just right,
I explored far & wide, blocked by lulling tide, all I found was you.
Needless to impart,
I want my money back...
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #2 (permalink)  
Old 11th August, 2004, 09:35 AM
Chief Systems Administrator
 
Join Date: September 2001
Location: Europe
Posts: 13,075

As far as I'm aware there are only two capacities for DVD-RAM media now. That is 4.7GB and 9.4GB. The difference between the 4.7GB and 9.4GB is that the 9.4GB media is double sided : AKA flip it over for the other 4.7GB of storage. This is opposed to the dual layer technology that competing standards use, where the disk does not have to be flipped to use the rest of the storage.

I have been unable to verify the claim of a million writes; manufacturers of media and drives as well as the RAM Promotion group appear to claim 100,000 writes.

The RAM Promotion group, who promote DVD-RAM, have released details of a 5x DVD-RAM spec. This places it slower than competing writable DVD technologies.
__________________
Any views, thoughts and opinions are entirely my own. They don't necessarily represent those of my employer (BlackBerry).
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #3 (permalink)  
Old 11th August, 2004, 12:01 PM
DimViesel's Avatar
Member
 
Join Date: April 2003
Location: Earth
Posts: 517

..but the loss in write (access too?) speed is more than made up for by certified reliability. I've seen reports of how DVDRW media is usable only in theory since light damage to the surface can cause irretrievable corruption.
Thanks for the reply Aedan.
Good to see you again too.
__________________
Searched near & far across networked lands for a sig. that would do.
I searched thorough, & wide, for a signature just right,
I explored far & wide, blocked by lulling tide, all I found was you.
Needless to impart,
I want my money back...
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #4 (permalink)  
Old 11th August, 2004, 01:59 PM
Chief Systems Administrator
 
Join Date: September 2001
Location: Europe
Posts: 13,075

I'm cautious to certified reliability. None of the manufacturers I looked at had underwritten the reliability of their media, which leaves me a little suspect. Certainly for CDs there are archival quality CDs which cost considerably more, but supposedly provide longer lifetimes.

Any exposure to intense light is generally bad for any media, be it CDs, paper, or even magnetic tape.
__________________
Any views, thoughts and opinions are entirely my own. They don't necessarily represent those of my employer (BlackBerry).
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #5 (permalink)  
Old 11th August, 2004, 07:39 PM
DimViesel's Avatar
Member
 
Join Date: April 2003
Location: Earth
Posts: 517

I am primarily concerned with the robustness & reliability of the medium.
I can see the reasoning in that if mini-disc can guarantee any level of robustness, then another cartridged opto-magnetic medium must be capable of a comparable feat. Simply because the write surface is protected from wear & tear.
I concur that you will always be wise to take manufacturer's upper limits with a pinch of salt...
Couple this with the unreliability of DVD-RW, DVD+RW (due to the surface being vulnerable to handling damage & due to the increased density, reduced size of DVD 'grooves & pits' the more likely that data corruption will result due to what would have been 'surmounted' by CDRW media, the price of those discs (RW DVD media either std.) & of Write once DVD-R/+R discs I am surprised those with backup requirements above those easily provided by CD capacity storage have not moved over (where a guarantee & continual updating of datasets is a requirement) to DVDRAM.
__________________
Searched near & far across networked lands for a sig. that would do.
I searched thorough, & wide, for a signature just right,
I explored far & wide, blocked by lulling tide, all I found was you.
Needless to impart,
I want my money back...

Last edited by DimViesel; 11th August, 2004 at 07:45 PM.
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #6 (permalink)  
Old 11th August, 2004, 08:33 PM
Chief Systems Administrator
 
Join Date: September 2001
Location: Europe
Posts: 13,075

There are tales of minidiscs being erased by strong magnetic fields. I haven't yet got around to testing this, but I have a couple of strong magnets for when I pick up a throwaway minidisc.

Archival CDRs are much better than standard CDRs for archiving material to. Properly stored archival CDs and backup tapes should last a good number of years. Remember also that the error correction on DVDs is also stronger than the error correction on CDs. Just think what Bluray's going to encounter!

Archiving material off is definately a problem in today's world!
__________________
Any views, thoughts and opinions are entirely my own. They don't necessarily represent those of my employer (BlackBerry).
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #7 (permalink)  
Old 11th August, 2004, 11:32 PM
DimViesel's Avatar
Member
 
Join Date: April 2003
Location: Earth
Posts: 517

Aedan I know you are the kind of guy who has his time filled without having to reply to threads on here.
However a couple of points I feel have not been made clear:
1slty, interesting point on minidiscs, but I don't believe minidiscs & DVDRAM rely on the same properties of the same substrate & so would not have common drawbacks.

I believe that if you handle & store CDRs correctly, then you can expect them to last somewhere in the region of the stated period by the manufacturer.

However it should not be necessary as data should be migrated to the the latest formats to ensure it does not become 'marooned' (irretrivable) due to being held & encoded on obsolete media/file formats.
Unless you are dealing with sever sized applications where data sets must be archived & duplicated for a completely redundant live application - then I think for most small businesses & semi-pro home users the difficulty becomes making the most of the archival process as to minimise time drain & maximize the no. of times info that is required is available for access there & then with minimal effort spent on searching & retrieval.
In this respect DVDRAM suits me because I can use it as a halfway house to more finalized (organised & verified, simplified etc.) & permanent data stores which are then added to the catalogue of information, tools & resources on site & across sites.
I know that at all times my data is safe right up until the last config changes & files I created by being able to write them to DVDRAM as they are created. DVDRAM I see as the idea medium term store with the capacity to hold info for extended periods of time if required & to have changes made to the data set without creating confusion of redundancy since the changes can be made to the same volume. Therefore simplifying the retrieval & audit of data sets.

Perhaps it just meets my very personal method of working/backup data management. It is just about the right size too - especially in double sided flavours. I was under the belief dedicated DVDRAM drives had two heads which accessed both sides at the same time negating the need to flip & reinsert the volume to access info on the other side.

BTW - Does the frequency of exposure to read-laser operations affect the longevity of integrity of data burned on a domestic std. CDR bulk media?
__________________
Searched near & far across networked lands for a sig. that would do.
I searched thorough, & wide, for a signature just right,
I explored far & wide, blocked by lulling tide, all I found was you.
Needless to impart,
I want my money back...
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #8 (permalink)  
Old 12th August, 2004, 09:42 AM
Chief Systems Administrator
 
Join Date: September 2001
Location: Europe
Posts: 13,075

I am dubious about the cheapest CDRs, as I suspect they're being produced down to a price rather than up to a spec. Whilst I understand that good handling and storage is highly important to ensure the longetivity of the data, it's also likely that CDRs won't receive that treatment in a typical small office environment.

I know where I am, CDRs do get mistreated!

I work in a fairly small company where we have about 7 employees or so. We rely on DLT for backup, simply because 40GB worth of data takes a long time to write onto multiple DVDs. The other issues we have is that it may not be possible to copy data from one media to another media due to client requirements. Fortunately, most of the data along those lines only needs to be kept secure for a few years.

You make a good point about the retreival of information. Having a backup is not good if takes days to get that information back again. I know for DLT we use a backup program that allows files/folders to be selected for backup/restore. This is all for our file server, as ths is the central repository for information.
__________________
Any views, thoughts and opinions are entirely my own. They don't necessarily represent those of my employer (BlackBerry).
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
last thread before i buy bonesaw Intel Motherboards & CPUs 34 29th December, 2006 03:53 AM
Phantom Thread Toro Forum Feedback and Suggestion Box 21 28th April, 2005 02:48 PM
Sorry, I had to start this thread so my thread count won't read 666 anymore. mookydooky Random Nonsense! 10 1st November, 2002 07:07 AM
new thread Dragons Gate Case Modifications 8 17th September, 2002 11:07 PM


All times are GMT +1. The time now is 03:53 PM.


Copyright ©2001 - 2010, AOA Forums
Don't Click Here Don't Click Here Either

Search Engine Friendly URLs by vBSEO 3.3.0