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
