XPost: comp.os.linux.advocacy, comp.os.linux.misc   
   From: jjb@invalid.invalid   
      
   On 30-09-2024 13:25, The Natural Philosopher wrote:   
   > On 29/09/2024 22:18, Paul wrote:   
   >> I would say that 6TB air-breathing drives (state on the lid   
   >> "do not cover this hole), those are archival material. I   
   >> would expect to power one up 20 years from now, and it will work.   
   >   
   > Well my 2TB drives only lasted about 6 years *powered on*.   
   >   
   > I am not sanguine about the lifetime of any magnetic media.   
   >   
   > There are hard drives from back in the 1980s that are still booted up   
   > after years in storage. Some boot, some don't, and some are just   
   > partially corrupted.   
   >   
   > Magnetic fields are no more permanent than electric fields in SSDs.   
   >   
   > SSDS are simply too new to have any reliable long term statistics under   
   > real working conditions.   
   >   
   > The short answer is that we are pissing in the wind when it comes to any   
   > long term digital storage.   
   >   
   > We know paper and ink lasts, we have the dead sea scrolls..   
   >   
   > We know that selenium treated photographs last at least 160 years, We   
   > know that first generation colour prints are seriously degraded after   
   > only 50...   
   >   
   > We know that some spinning rust 40 years on is still data recoverable ,   
   > we know that a lot is not.   
   >   
   > Often for other reasons than magnetic corruption - corrosion on drive   
   > spindles etc. Dead capacitors in the onboard electronics   
   >   
   > A decent cosmic ray knifing through any modern electronics will fuck the   
   > DRAM up  to the point where the machine may crash.   
   >   
   > No problem. Reboot it...   
   >   
   > There are no perfect solutions All data is to an extent written in   
   > 'vanishing ink'   
   >   
   > But my current best guess is that a rolling replacement of mirrored   
   > disks (rust or SSD) as they show error counts in  a 24x7 powered machine   
   > is probably as good as it gets, and the smaller and slower the storage   
   > is, probably the less stressed it will be. Looking at SSD current draws,   
   > it is the cheaper slower ones that seem to draw less and run cooler.   
   >   
   > The best news is that we have SMART. And failing but not yet failed   
   > drives due to ageing show up in terms of parity errors. On a 24x7 system.   
   >   
   > No one knows till they power up a 40 year old drive whether or not the   
   > data is either still there, or is recoverable.   
   >   
   >   
   > So my wet finger is moving towards permanently on, lower power, larger,   
   > slow SSDS. From permanently on spinning rust.   
   >   
   > My personal server was first built in 2000 or thereabouts. Debian Linux.   
   > It's on its 4th motherboard and its third set  of hard drives, and its   
   > umpteenth OS upgrade. but the data is still there from 2000 or so.   
   >   
   > I am constructing, slowly, a replacement based on a Raspberry PI and   
   > twin mirrored SSDs,   
   >   
   > When its shown to be reliable, I may switch off the *86 based one   
   >   
   > I have had another thought, and that is why we 'archive' in the first   
   > place. That goes back to the days when  *working* storage was small, but   
   > the need was for stuff to be available for occasional use from slower   
   > media like tape.   
   >   
   > Today, with SSDs, our *working* storage can be enormous. And fast. We no   
   > longer need traditional data archives. Just leave it all on the running   
   > machine, and mirror it.   
   >   
   > If you must have 'offsite storage', rsynch another portable  drive every   
   > so often and take it away to somewhere safe.   
   >   
   As regards to magnetic storage: if it is a magnetic tape, its not   
   lasting that long.  I had to extract some data from a several years old   
   magnetic tape once.  Fortunately I decided to read and store the whole   
   tape in one go.  After it had passed the heads in the tape unit, the   
   complete magnetic layer ended up as dust on the bottom of the unit...   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)