[jatrax]

Taiyo Yuden and Verbatim are the brands usually recommended but it is important to remember that the 'brand' consists of a range of media from cheap throw away to archival quality. Just buying Verbatim at the grocery store is not going to get you archival quality.

And according to the US National Archives CD/DVD media has an average life span of 2 - 5 years. They also state that despite manufacturers claims to 10 - 25 years this has not been born out in experiential testing. They recommend testing all CD/DVD media every two years and replacing as needed.
Frequently Asked Questions (FAQs) about Optical Storage Media: Storing Temporary Records on CDs and DVDs

M-Discs use a different, hotter laser and an inorganic substrate for recording. They claim 1,000 year life span. Millenniata Discs: ?More Than? Archival Storage On American-Made DVDs | Shutterbug

Personally I don't think the classic 'archive' has much meaning anymore. You should be thinking of managing your digital library rather than 'archiving' it. Archive implies writing it to something and then locking it away until you need it. Managing means keep the library current, with multiple backups on different media with the library constantly being migrated to new technology and media as it becomes available. I am very concerned that a lot of digital content 'archived' on optical media will simply not be readable when you go back to it in 10 years.

[haycyn]

This was one of the biggest arguments I encountered when coming over from film. I thought I would just print them all.
Yeah, no.
What is the consensus on the best way to store the photos? Rotate 2 external hard drives?

[Racer X 69]

And according to the US National Archives CD/DVD media has an average life span of 2 - 5 years.

Then how is it I have music CD's from when they first came out over 20 years ago that still play as well as the day they were unwrapped?

[jatrax]

Then how is it I have music CD's from when they first came out over 20 years ago that still play as well as the day they were unwrapped?

1. As I understand it music CD's that are 'pressed' at the factory will last longer then 'recordable' ones burnt with a laser. I assume the same is true of DVD movies but I don't know that. The reason I have seen is that recordable ones use organic dyes that degrade over time.
2. I have also been told that even if there are errors on a music CD it will still play and the error correction will cover for the error. This is not always true of digital data which is stored as discrete files rather than written as music tracks.

Also note that the life span is given as an average so it is quite likely some disks will last quite a long time. The actual life span of optical recordable media depends on the quality of the media, whether the media is intended as a throw away or archival, the quality of the burner, and the environment the media is stored in. Temperature and UV radiation seem to be particularly detrimental to the dyes in DVDs, so storing in a light tight, temperature controlled area will definitely help.

The National Archive has stated that optical media (CD-ROM and DVD) should not be considered archival and have done testing to show that it should not be relied on. My point really was that data you want needs to be managed with multiple backups on different types of media in different locations, not 'archived' and forgotten until you need it.

[adwb]

Is it not better in that case to back up to SSD or any other form of non moving storage like memory cards/sticks?

[jatrax]

Is it not better in that case to back up to SSD or any other form of non moving storage like memory cards/sticks?

Not necessarily, my point is that backup should be a management process not just worrying about what media is used. Any media can fail, be destroyed, stolen or lost. So to actually have secure backups you must 'manage' your digital assets. This should be across multiple media and multiple locations. And this needs to change over time as the library is migrated to new media as it becomes available.

[Anvh]

M-Discs use a different, hotter laser and an inorganic substrate for recording. They claim 1,000 year life span. Millenniata Discs: ?More Than? Archival Storage On American-Made DVDs | Shutterbug.

Intersting, will have a look.

However for a lot of data we are using blu-ray now. Actually now idea how long they last...

[wildman]

What is the consensus on the best way to store the photos? Rotate 2 external hard drives?

1. There is no consensus
2. Accept the fact that whatever you do some data will probably be lost no matter what you do either through gear failure or operator error.
3. The most you can do is come up with a system that best meets your needs and is also practical with respect to time and money but will not be perfect.

For myself I use two external drives one is database A and the other B.
Database A is the active one where I add, delete, rename, change the file structure etc and then when done with A mirror it over to database B so I end up with two ongoing, running identical redundant independent databases.

Because I do the mirroring about once a week I have the advantage of watching for any errors in the transfer that might alert me that one of the drives may be getting flaky
.
Finally, perhaps once a year, I select a limited amount of files that I particularly value and burn two sets of DVDs for a bit more safety. At this point, in my case, this only involves 4 disks - two identical 2 disk sets.

Done.

[Racer X 69]

For myself I use two external drives one is database A and the other B.
Database A is the active one where I add, delete, rename, change the file structure etc and then when done with A mirror it over to database B so I end up with two ongoing, running identical redundant independent databases.

Because I do the mirroring about once a week I have the advantage of watching for any errors in the transfer that might alert me that one of the drives may be getting flaky
.
Finally, perhaps once a year, I select a limited amount of files that I particularly value and burn two sets of DVDs for a bit more safety. At this point, in my case, this only involves 4 disks - two identical 2 disk sets.

Done.

After running the backup to the B drive, how to you go about verifying the integrity of the data?

[wildman]

After running the backup to the B drive, how to you go about verifying the integrity of the data?

The sofware does a checksum on the fly.
Note:the mirror function is not a brute force total backup but only changes what needs to be changed not the whole database and typically takes less than a minute.

See pics of a mirror run I just did this morning and works fine for my purposes-

[Racer X 69]

The sofware does a checksum on the fly.
Note:the mirror function is not a brute force total backup but only changes what needs to be changed not the whole database and typically takes less than a minute.

See pics of a mirror run I just did this morning and works fine for my purposes-

Looks nice. I suppose I should have asked earlier, what are you using to do this?

[wildman]

Looks nice. I suppose I should have asked earlier, what are you using to do this?

Download SyncToy 2.1 from Official Microsoft Download Center

[Racer X 69]

Download SyncToy 2.1 from Official Microsoft Download Center

Thanks wild guy!