From: nospam@needed.invalid   
      
   On Mon, 5/19/2025 6:22 AM, Carlos E. R. wrote:   
   > On 2025-05-19 12:14, Paul wrote:   
   >> On Mon, 5/19/2025 5:28 AM, Carlos E. R. wrote:   
   >>> On 2025-05-19 01:37, Paul wrote:   
   >>>> On Sun, 5/18/2025 4:41 PM, Carlos E. R. wrote:   
   >>>>> On 2025-05-18 21:40, Paul wrote:   
   >>>>>> if the disk drive company won't be honest with us, we have to   
   >>>>>> come up with some sort of solution for an early warning.   
   >>>>>   
   >>>>> At least Seagate disks come now with a very extended logs. In Linux I   
   obtained them with "smartctl -d sat -l farm /dev/sdX":   
   >>>>>   
   >>>>> This is the end part of one:   
   >>>>>   
   >>>>>                   Number of Reallocated Sectors by Head   
   0: 0   
   >>>>>           Number of Reallocated Sectors by Head 1: 0   
   >>>>>           Number of Reallocated Sectors by Head 2: 0   
   >>>>>           Number of Reallocated Sectors by Head 3: 0   
   >>>>>           Number of Reallocated Sectors by Head 4: 0   
   >>>>>           Number of Reallocated Sectors by Head 5: 0   
   >>>>>           Number of Reallocated Sectors by Head 6: 0   
   >>>>>           Number of Reallocated Sectors by Head 7: 0   
   >>>>>           Number of Reallocated Sectors by Head 8: 0   
   >>>>>           Number of Reallocated Sectors by Head 9: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 0: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 1: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 2: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 3: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 4: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 5: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 6: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 7: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 8: 0   
   >>>>>           Number of Reallocation Candidate Sectors by Head 9: 0   
   >>>>   
   >>>> OK, added to my notes file.   
   >   
   > If you want to see the full log, I can post it. I had a look just after   
   purchase, checking to see the disk was actually new.   
   >   
   >>>>   
   >>>> That must be a decent capacity disk, to have that many heads.   
   >>>> Five platters I guess.   
   >>>   
   >>> It is a "Seagate IronWolf Pro NAS 10TB 3.5" SATA 3". I can't believe it   
   has that many heads. But it takes 30 seconds to start up, so the platters must   
   be heavy, or the motor is current limited.   
   >>>   
   >>   
   >> Yeah, current limit. My sample big drive (only an 18TB one), it   
   >> takes a while to spin up, and it also screws around a bit before   
   >> it becomes ready. It's not just loading the firmware off the   
   >> platter (which is the minimal requirement).   
   >>   
   >> I notice they're allowing drives up to and including 14TB   
   >> to breathe air, and I bet one of those would be slow to start.   
   >   
   > Yes, it is an air breather, I noticed the hole covered with some kind of   
   gauze or filter.   
   >   
   > They could just fill with nitrogen, if helium is expensive.   
   >   
   >>   
   >> The platters are thinner, when there are a lot of platters   
   >> in there, so they don't have to be as heavy as the platters   
   >> in a four platter drive.   
   >   
   > I guess. This is not a fridge sized disk, after all :-)   
   >   
      
      
   There was a press release some time ago, indicating they were   
   working on thinner platters, in order to squeeze more platters   
   into the one inch high drive housings. The thin platters may   
   be made of glass, and then the plated-up stack is put on the   
   outside.   
      
   *******   
      
   It's a good question why they couldn't use Nitrogen. Or for that   
   matter, why the air-HDA could not be sealed. Helium might have a   
   different viscosity, and "flying characteristic" for the head,   
   which is why the Helium pressure is a bit above atmospheric.   
      
   The air breather drives were supposed to be that way, to avoid   
   "tin-canning" of the lid, as barometric pressure changes. The Helium   
   drives on the other hand, have two lid plates, one gas-tignt, one   
   plate a mechanical reinforcement. If they used a fancy lid, I don't   
   see why they couldn't seal the air-based drive. The data recovery   
   people aren't going to like it. There have already been some   
   joke videos, where they portray their attempts to try to get the lid   
   off a Helium drive (welded on), for data recovery.   
      
   It means if you have a Helium drive, and you let it get too old and   
   crusty, data recovery might be more difficult (or do-able by fewer   
   people), than the air drives that unscrew easily.   
      
   The head stack in a Helium drive, would only have the correct flying   
   height under Helium fill to the correct pressure. If the housing   
   was filled with air, it is unclear whether you could even make it work   
   well with air present. The heads have "lift" and the lift surface   
   is scaled according to the gas being used. The "lift" effect counteracts   
   the spring constant of the arms. The flying scheme allows the drive   
   to run on six-axis.   
      
      Paul   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)