XPost: comp.os.linux.advocacy, comp.os.linux.misc   
   From: nospam@needed.invalid   
      
   On Mon, 9/30/2024 7:25 AM, The Natural Philosopher wrote:   
      
   > No one knows till they power up a 40 year old drive whether or not the data   
   is either still there, or is recoverable.   
   >   
      
   There are properties studied in isolation, but there   
   does not seem to be that much research interest in the   
   archival properties of hard drives.   
      
   Part of the reason, is the physical construction is always   
   changing, and each era can have a different failure mechanism.   
      
   The chances of the drive making it to 70 years and not having   
   enough magnetic signal, are pretty limited. You are just as   
   likely, to suffer some other kind of failure. And the Helium drives,   
   they remove all the uncertainty about 70 years as a target figure.   
   The glass platters and the loss of helium, say hi. The platters   
   had to be made thinner, to put ten platters in an inch thick drive.   
      
   As home users, our usage of hard drives for backup, is purely   
   coincidental. The hard drive companies do not place a premium on   
   that behavior or application. The drive has as priority,   
   nearline storage and "as much capacity as you can manage". That's   
   why the Helium drives are a poor match for what a home user   
   might wish to achieve. A home user, uses Flash, because Microsoft   
   told them to. They back up their flash (whether eMMC, SSD, NVMe),   
   with a hard drive. But then it depends on what kind of hard drive   
   they bought, whether they are "well covered". The 6TB air breathers   
   are still a good choice for archival storage. The 24TB Helium drives   
   on the other hand, they're not a good match for archival store.   
      
   This is an archival drive. 20 years from now, this will work.   
   "Do Not Cover Any Drive Holes" means it is an air breather (no helium).   
   There could be 3 to 6 platters (they stopped reporting platters in   
   the data sheet, a long time ago, as well as honestly reporting   
   CMR versus PMR). 4 platters is a good number, but they could   
   do it with 3 platters now.   
      
   "WD Black 6TB"   
      
   https://i.ebayimg.com/images/g/Hh8AAOSw2~VlRLQm/s-l1600.jpg   
      
   This is not an archival drive. The outer lid is welded on.   
   It does not unscrew at the Data Recovery lab. Your data is   
   trapped in there, and it ain't comin back.   
      
   "WD Gold 24TB"   
      
   https://cdn.mos.cms.futurecdn.net/nJ59TSmXcVxrM35UVnYJzF-1200-80.jpg.webp   
      
   One of the drive companies, put a pressure sensor in SMART, but   
   it's not documented, so we can't "plot helium pressure versus year" for fun.   
   The other company didn't put anything in that slot. I have not seen   
   any info, on the number of BARs of gas pressure in there. It is whatever   
   amount of gas that is needed, to make the heads "fly". And a drive like   
   that, is likely to have the fly sensor (DSP measures head current, to   
   compute flying height on a write). A WD Blue 1TB drive, has sweet nothing,   
   in terms of technical content, and it does not sense flying height.   
   It doesn't need to. It doesn't have piezo positioners right at the head.   
   If you put eight WD Blue 1TB in a drive rack, the vibration from all   
   the drives, would prevent them from performing properly. One WD Blue 1TB   
   by itself should be fine.   
      
   I had a WD Blue and the farking thing was on one of the six axis   
   allowed for drives, but the drive is NOT happy, if half way through   
   its life, you change the orientation. Once you pick to run it horizontal,   
   keep running it horizontal. Don't flip it upside down, if you can   
   avoid it. There was a time, when horizontal was the only axis allowed.   
   But that changed at some point, to a six axis specification (horizontal   
   right side up, horizontal upside down, being two of them).   
      
      Paul   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)