Re: causes for this?
On Saturday 23 June 2018 09:18:29 David Pottage wrote:
> Is it a new SSD that has not been used before? Did you start copying
> data shortly after powering it on for the first time?
No, its been prepared by gparted, and has 300 or so powerup hours
already, although only the ext4 file system was written to it.
> I saw similar behavior with an SD card a few years ago, and came up
> with a theory that when new the SSD controller needs to test all the
> flash to build up a bad blocks map, but most this is not done in the
> factory, only when the device is powered for the first time.
> So when you first plug in a flash device, only a few megabytes are
> actually available for writing, and the controller is busy running
> self test routines on the rest. Any writes to the untested parts of
> the flash get queued behind the testing so will be quite slow. Most
> users would not notice an effect, especially with SD cards in digital
> cameras because they are powered all the time and only filled
Sounds plausible, but you'd think they'd want to test it just to stop the
shipment of bad product. But then I've had an automatic contract out for
bean counters since one of them cost me 6 months fighting with an
intermittent in a radio transmitter. But when I finally caught it in the
act, I was so upset I called the maker, got the head design guy on the
phone and told him he wasn't complete, the best part had run down his
mothers leg. He had speced a ultra cheap motorized powerstat, with an
alu contact ring, and did not have one with a brass contact ring to
offer as a replacement. So I bought the $90 piece of junk and made a
brass piece to match it. End of problem.
> Of course this is all just a theory with no real evidence to back it
> up other than a cynical view of flash drive manufacturers cost
> cutting, but as a work around I now make a point of plugging in a new
> drive and leaving it to sit powered but not otherwise in use for a few
> hours before I start copying large amounts of data.
The Cynical view has been well earned by the flash suppliers.
Anyway, I had a 7 minute power failure that killed it long before my
auto-starting 20 kw brought the lights back up, so I blew away what it
did get done, and sent unzip after it, which did the unpack in just a
couple minutes. So that parts done.
Now I need to locate a source for xelatex so I can print the docs and get
started. apt can't find it it the repo's. Sigh... Hints welcomed of
Cheers, Gene Heskett
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>