Wow!
My article on the life-expectancy of magnetic signals on hard disks in this month’s newsletter has really touched a nerve!
If you want to read it, we’ve turned it into an article, which you can read here: /articles/hard-disk-warning/
Since that was published, I wanted to share some more information that is relevant to this discussion. First, and most important, hard disks vary. One person wrote saying they lost media after a year. Another wrote to say he checked drives that were eight years old, and they were OK.
The key point is to CHECK YOUR HARD DRIVES! Don’t assume, as I did, that once its on the disk everything is OK.
This article also opened a debate on the shelf-life of hard drives. This, too, is currently impossible to quantify. As one engineer wrote:
The toughest thing to do is to get a disk platter spinning at start-up. In the early days of disk drives, “stiction” prevented many drives from starting up if the power supply was insufficient, or the disk lubricants were more viscous than when originally applied. The modern drives improve the situation immensely — lubricants that are more stable in their use over the entire storage and operating
temperature range; these lubricants are in the bearings and no longer on the disk surface. Heads automatically retract to a safe area off the disk surface when drive is powered down, rather than resting on the surface. Disk material is more “flat and perfect” eliminating the need for any lubricant coating on the surface. All told, the improvements over time require less power and concern for initial disc spin up.Recording technology and reading technology have significantly improved. Combined with new disk surface material, the disk surfaces are more tolerant of recorded data fading. There are shelf life studies in various journals that track this phenomena. The good news is that drives built over the past several years have made significant improvements. However, no manufacturer has developed an actual spec to define the data retention lifetime.
The narrow point I made was data readability of disk drives used for archives. The simple advice of spinning the drive up on occasion, and refreshing the data touches on only part of the solution. Users will also need to consider what data formats they are reliant on, and the need to migrate their assets as the technology changes over the years.
Here’s my point — as we all are discovering as we move into HD, tapeless media, and file-based editing, what we don’t know can often cripple a project.
Keep asking questions — test your ENTRE workflow — and keep in mind what I taught my daughter as she was learning to drive: “Remember, drive as though everyone was out to get you.”
Let me know what you think.
2 Responses to More Thoughts on Hard Disk Reliability
Annual spin-up is easy enough, but if drives really need annual sector by sector verification and reallocation of any bad sectors to assure safe storage of data, that brings up a whole other set of issues.
I saw a that Larry’s suggestion was to consider copying the data from one drive to another. I can see how this might handle the sector reallocation issue, but it also raises the possibility of problems during the copy as well as the huge amount of time involved for anyone that has a large number of drives in their archives. There must be an easier way.
On the other hand, it seems highly unlikely that just spinning up is typically going to initiate a process of sector repair. Even if this is the case in certain specific contexts (some HighPoint SATA RAID PCIe cards seem to offer this functionality, without specifying when it occurs) it does not appear that background sector reallocation is the kind of information that an end user would be given information on or have a way to evaluate.
If a sector reallocation pass really is an issue for archived data, what’s the simplest way to accomplish this for a Macintosh user?
I contacted an engineer who has expertise in this area to ask about this today. He suggested I go with drive testing and repair utilities specific to each brand of drive, which are offered on the support > download pages from its manufacturer. I’ve noticed, however, that both Hitachi and Seagate’s sites, for example only offer these utilities for Windows and DOS, which seems likely to be typical.
Is there a reliable Macintosh utility that could perform this function without any risk to the data for a variety of drive manufacturers? Apparently one concern is that various DRIVE manufacturers have different routines written in the firmware for sector allocation, and it would be important for the drive utility to understand the various protocols.
Thanks, Stephen
Thanks, Stephen Gagne
Westwood Creek Productions
Well said Larry! Often I face productions that claim they can’t afford to pay to properly archive a project. In reality, what they REALLY can’t afford is to go back and reshoot the lost material. In these days of tapeless cameras (RED, Genesis, P2, EX3, etc.) proper archive of the material should be factored into the cost of a production from the beginning. Disk drives should be used for storage, not archival. New technologies like holographic storage are poised to bring long term archival to the masses. Look for companies to start offering archival services for those that can’t afford to buy a $19,000 archival solution.