Why does a CD surface turn Gray colour?

[eyepea]

Please look at the image at : http://www.flickr.com/photos/eyepea/6149551212/in/photostream

The CD shown in the bottom left is OK.
The CD shown in the top right looks as if some Gray colour substance has spilled on it.
DVD player says CD dirty and cannot read.

Nothing spilled on it. There is no difference in the texture of the surface either. Tried cleaning it with a soft cloth and also with plain water and then with mild soap and water, no luck.
This looks like something inside the CD itself (I may be wrong).
Both the CDs were stored in the same place with many other CDs. I observed this phenomenon only on this CD.

What is the issue ?
What may have caused this CD to turn a Gray colour ?
Thank you.

 

[psyco]

I have had this problem as well, u can just peel of the media. may be humidity

 

[nadman]

got the same problem with some of my old dvds.They dont read at all now.Cheap media i think.

 

[kosandpol]

Its because of the cheap materials used in the CD.
see : http://www.instantfundas.com/2007/08/why-recordable-cddvd-does-not-last-long.html

and : http://lateblt.tripod.com/fadingcd.htm

 

[eyepea]

many thanks for the info!

Backing up info is going to be a big worry

 

[kosandpol]

many thanks for the info!

Backing up info is going to be a big worry

if these are important data, recommend you use a dedicated external drive only to store the backups.

 

[eKingmaster]

ela ela

 

[nadman]

if these are important data, recommend you use a dedicated external drive only to store the backups.

Thats what I do usually.But isnt there a chance that these can get corrupted.You need a Raid setup or something with mirrors to be sure.

 

[kosandpol]

Thats what I do usually.But isnt there a chance that these can get corrupted.You need a Raid setup or something with mirrors to be sure.

they should be used only to store and restore the backups and you have to mount and unmount them properly.
If you are using a RAID setup to overcome disk corruption then you need at least RAID 5.
Needless to say that this is fucking expensive!

 

[nadman]

they should be used only to store and restore the backups and you have to mount and unmount them properly.
If you are using a RAID setup to overcome disk corruption then you need at least RAID 5.
Needless to say that this is fucking expensive!

I know what you mean I am currently using a external desktop drive and an old internal hard drive for backups.Raid 5 is out of the question cause I'v got 5TB of hard disk space on my p.c.

 

[kosandpol]

I know what you mean I am currently using a external desktop drive and an old internal hard drive for backups.Raid 5 is out of the question cause I'v got 5TB of hard disk space on my p.c.

I meant RAID5 on the backups solution. Which means you have to use an external NAS or SAN solution for backups.

 

[nadman]

I meant RAID5 on the backups solution. Which means you have to use an external NAS or SAN solution for backups.

Yes,it would be expensive.BTW can you download torrents via a NAS?

 

[kosandpol]

Yes,it would be expensive.BTW can you download torrents via a NAS?

Depends on the NAS controller's features.most can run torrents. On some. you can install a torrent software.

 

[nadman]

Depends on the NAS controller's features.most can run torrents. On some. you can install a torrent software.

Thanks.Been thinking about getting one.

 

[kosandpol]

Thanks.Been thinking about getting one.

keep in mind that RAID 5 needs minimum 3 disks..