Benchmarking CMR vs SMR

[Arwen]

On occasion, external USB attached CMR drives, (3.5"), work well for backups. However, their are problems:

• Leaving USB drives attached semi-permanently may not work, (or work well).
• Heat can be an issue. Many USB enclosures are designed for casual use, not very regular, full blown backups.
• At some point, size wise, you may want something larger. (You want 3 x 2TB, which could be replaced by a 6TB single drive).
• USB 3 speeds can be irregular when compared to SATA, (or SAS), interface(s).

Anyway, I wrote this about USB attached drives for data pools. Some applies to USB drives attached for backups, though not all.

Why you should avoid USB attached drives for data pool disks

This subject has been coming up quite often in the last year or 2. Perhaps because of TrueNAS SCALE has brought forth some attention to TrueNAS in general and ZFS in specific. Please note that this is about USB attached storage for ZFS data...

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