There are only three disk drive manufacturers left. Western Digital Seagate Toshiba
On Sun, Nov 1, 2020, 1:38 PM Keith Lofstrom <[email protected]> wrote: > I want to purchase more backup hard drives: > 3.5 inch SATA, 6 to 10 TB ( best price per terabyte ), > 5400 RPM ok, reliability important. > > Who makes, and who sells, reliable "CMR" hard drives > with a decent (3 to 5 year) full replacement warranty? > Who should I avoid? > > I would especially like to hear from those who recently > purchased drives for RAID arrays; an application with > the same write performance requirements as mine. > > ---- > > long winded explanation: > > Since my last backup hard drive purchases 2-3 years ago, > "CMR/PMR" ( Conventional/Perpendicular Magnetic Recording ) > hard drives models are being replaced with "Shingled" hard > drives, which squeeze more bytes on fewer platters, but > have much slower write latency. > > Write latency (time to complete an operation) is critical > for my backup application, which often rewrites filesystem > directories. > > Shingled writes don't just rewrite sectors or tracks, but > 256 megabyte groups of tracks. The write head is wider > than a readable track, so a SHINGLED write requires reading > all 256 MB into a RAM cache, changing the sectors in RAM, > then writing back the entire 256 MB block on top of the > old 256 MB. > > This allows denser track spacing; with current technology, > a write head is wider than a minimum-sized read head. So, > SMR drives write a wide track overlapping the edge of the > previous track in the spiral ... "shingling", like the > overlapping shingles on the roof. > > Clever, in the same sense as a cheapskate using both sides > of the toilet paper. Similarly slow and dirty, IMHO. > > ---- > > I looked on Amazon (I have Prime, they deliver fast), and > struggled through dozens of candidates that are CMR model > names that now use SMR. From the "Majors": Western Digital, > Seagate, Toshiba, all of whom have been exposed as SMR > "bait-and-switch" vendors. Many Amazon hard drives are > "refreshed" with a 90 day warranty. I had to read through > a lot of Q/A messages from users (some of whom are shills) > to figure this out. Frustrating. > > It would be nice to have new drives in a week, but I am > in no hurry to fail over the next two years. Amazon is > fast and sometimes inexpensive, but not trustworthy. > I'd rather help the startup that eats their lunch. > > Keith > > -- > Keith Lofstrom [email protected] > _______________________________________________ > PLUG: https://pdxlinux.org > PLUG mailing list > [email protected] > http://lists.pdxlinux.org/mailman/listinfo/plug > _______________________________________________ PLUG: https://pdxlinux.org PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
