Return to best method to archive images

[nickc1]

<p>I appreciate that the question of the best method of archiving images has been gone over many times here, but my experiences over the last few days make me question much of the perceived wisdom I have read.<br>

The occurances have been:<br>

My ISP has changed hands without my knowledge, until my eMails stopped - I have had to change a setting (a mistake on my part admittedly, but acceptable under the old regime, but not under the new) before they resumed.<br>

I have just 'buried' the third external hard disk drive that has failed outside warranty during the last two years (2 x Lacie, 1 x Packard Bell)<br>

I have had to load software from a home written CD R that was at least 10 years old, with 100% success.<br>

What I am now wondering is if the advice I follow to back up onto external hard disks and online rather than to CD is still the best way - granted my experiences are only one persons, but they are suggesting that these methods are not the cure all I had thought them to be!<br>

What have others experiences been?</p>

[rainer_t]

<p>I don't see what your ISP's role in this question is ... so I reduce my view to the following:</p>

<p>You had an external drive dying recently ... and this has happened top you before ... you found, that a 10 year old CD is still working.</p>

<p>Therefore your question ... shouldn't you be doing your backup onto CDs.</p>

<p>Well both harddrives and CDs are known to be things that can fail (and they indeed do).</p>

<p>So, relying on only ONE external harddrive is not good enough ... backup to at least TWO independant external harddrives. It is very unlikely (albeit not impossible) that both of them fail at the same time. And even if they do .. the two drives should be backupdrives ... so the data should be somewhere else as well.</p>

<p>Backing up onto CD is very unconvenient ... you need about 1500 CD to backup one Terabyte ... so, the question is, what do you find easier to handle and to store ... the 3000CDs (you want two backups) or 2 external disks with 1TB each.</p>

[nickc1]

<p>Thanks for your reply Rainer - my resons for wondering about an ISP (especially in the current economic climate) is that if an online repository can become unavailable could I ever get my data back?<br>

I agree that CDRs are inconvenient - but my recent experience has been that they appear to keep working - and both of my original mirrored HDDs have failed, fortunately not at the same time, so I have always been able to recover data, hence my desire to see if my experiences are typical. </p>

[Craig_Cooper11664875449]

<p>Unless you have a service level agreement (SLA) with your ISP to store data then they dont count. Almost all accounts I ever read about of external drives failing are those pre-packaged drive cases. Whether its over-heating or just poor QC, I dont know.</p>

<p>Personally, I use network attached storage as my primary data drives with 2 in a RAID 1 configuration, which gives me hardware redundancy. I choose the drives and deliberately ensure they are of different vendors (1 seagate + 1 WD, both 1TB). As well the NAS is well cooled with large fans. Weekly, I do incremental backup to the internal drives. All files are placed in folders to a maximum of 4.3 GB at which time I burn to 2x Taiyo Yuden DVDs. One set kept at home, the other at the office.</p>

[Ed_Ingold]

<p>Hard drives can and do fail, taking with them often huge libraries of data. Consider hard drives as a "backup", not an "archive", even if you don't run them continuously. Magnetic media of any sort are subject to degradation, particularly cross-talk and through-printing (tapes), rendering them unreadable within a few years (HDD are continually refreshed when in use).</p>

<p>In my opinion (and experience), optical media are the most reliable means of archiving available to the general public (an IT staff and multiple RAID boxes might be better, until the money runs out). Tales of discs fading with time are unsubstantiated. In my experience, bad discs were bad from the get-go or have been physically damaged. Even scratches, other than on the backside, are ignored or can be buffed out. I make thousands of discs each year through my AV Recording business, and become acutely aware of any problems or trends.</p>

<p>CDRs have the best available chemistry (phthalocyanine), but are too small for today's image sizes. DVDR chemistry (Azo) doesn't work well in CDRs, but appears to be robust in its DVDR version. The sensitive layer in a DVDR is protected between two polycarbonate layers, where it can't be scratched. Delamination is the greatest hazard, so the discs must be handled gently and not bent in storage. I use Blu-Ray discs for really big files (e.g., raw video), but am apprehensive that the sensitive layer is on the reading surface, not really protected. The technology is just getting its legs, so it's too early to judge its physical (or technical) longevity.</p>

<p>There are a few rules to follow. (1) Select good media (e.g., Mitsui and Taiyo Yuden CDRs and Verbatim DVDR). (2) Use good software (e.g., Nero), write "disc at once" and finalize the disc. (3) Always "verify" the new burn against the original files. That's a check box with most burning software. (4) Periodically do an error check on recent burns and new media. Infinadyne Diagnostic (q.v.) is a good tool, also for recovery. Plextools (for Plextor drives only) is very good, but seems to have been phased out. (5) Store the discs so they can't be scratched or bent. Jewel cases give good protection but are bulky and fragile. I use archival pages by Case Logic, which hold 8 discs and fit in a ring binder. (6) Make multiple copies and store the duplicates in a separate location (in case of fire, flood or other disaster).</p>

[guido_h]

That's why I went back from digital to film. I've already got unreadable images from 9 years ago, but my 40-year old negatives still look beautiful.

[g dan mitchell]

<p>I do three backups. I use three different backup applications. One is done automatically every hour without intervention to a computer on my network in another location - this backup does not delete the older files but adds the new ones, so I can retrieve a version of a file from weeks or months ago if necessary.</p>

<p>The second is done automatically once per week, also over the network. This one creates a disk image of the main drive in its current state.</p>

<p>The third is done periodically to another drive that is stored at a remote location between backups.</p>

<p>Dan</p>

[cudacar2000]

<p>To me it has always been a non-issue - do NOT trust hard drives. RAID is no protection from anything but a simple drive failure. There are so many ways to mess up your data that they cannot be trusted (despite the fact that they are more convenient, and some people have had no failures - yet!).<br>

By all means use hard drives for storage and one level of backup - but do not rely on them. Optical media is by far the safest way we have now of storing data safely. They are not perfect, do not trust them either, but you can (and should) make multiple copies. They also have the benefit that you can make an extra set, and store it at your kids/parents/uncles/buddies place. There are also some interesting on line ways to back up to a friends computer - for free (CrashPlan, and probably others). I worry a bit that the vendor of those services would go under, but even if they did, I still have my originals, and I am pretty sure I could restore it locally if I had to.<br>

I always say there are two kinds of people in the world - those who make proper backups, and those who will.</p>

<p> </p>

[alan_ginman]

<p>"That's why I went back from digital to film. I've already got unreadable images from 9 years ago, but my 40-year old negatives still look beautiful." You are right, film images are inherently more stable than electronic ones, but you only have one copy of the film. If anything happens to that, your image is lost. Digital archiving is harder work but gives you the benefits of lossless copying and offsite backups. I also make prints of my best pictures and I suspect that these are the versions of my images that will be the most useful. Plus, they are easy to look at.</p>

<p>Regards</p>

<p>Alan</p>

[joe_pee]

<p>Is it possible to get a metal pressed dvd like ones bought in store? Like send someone your data, they send u disk?</p>

[bill_tuthill]

I believe store-bought DVDs are less reliable than Azo DVD-R or DVD+R, but have no experimental data to verify my belief. It's just that so many rental movies skip, fail, or go wacky. Listen to what Edward Ingold says - he is the expert here.

[cudacar2000]

<blockquote>

<p>Is it possible to get a metal pressed dvd like ones bought in store? Like send someone your data, they send u disk?</p>

</blockquote>

<p>Possible - I guess with enough money. But the process involves creating a die (not dye) to press copies into a metal layer, then encasing that layer in a DVD. It would be hideously expensive for one disk, but if you want a few thousand backups (even I am not <em>that</em> paranoid) it would be an option.<br>

The real answer - unfortunately not, at least for small quantities.</p>