[rescue] expanding a ZFS pool: leave slack space?

[Scott Newell]

At 03:48 PM 5/1/2021, Peter Corlett wrote:
>On Fri, Apr 30, 2021 at 12:42:44PM -0500, Scott Newell wrote:
>[...]
> > My concern is that in the future a replacement drive might not be exactly
> > the same number of sectors, and if it's too small, the mirror obviously
> > won't accept it.
>
>The number of sectors for a given capacity disk is standardised, and has
>been for over a decade:

Here's an example of what I'm concerned about. Two different 32 GB 
SSDs, yet it appears (according to both smartmontools and gdisk) that 
they don't have the same number of sectors!

One reports as 32,017,047,552 bytes [32.0 GB] (62533296 sectors) vs. 
31,675,383,808 bytes (61865984 sectors) [31.6 GB].

snipped from smartctl -a output:

Device Model:     TS32GMTS600
Serial Number:    F296620032
LU WWN Device Id: 5 7c3548 1774ecc00
Firmware Version: O0918B
User Capacity:    32,017,047,552 bytes [32.0 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    Solid State Device
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ACS-2 (minor revision not indicated)
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Mon May  3 16:11:43 2021 UTC
SMART support is: Available - device has SMART capability.
SMART support is: Enabled


Device Model:     M2SCF-6M 32GB
Serial Number:    20171130017109200335
LU WWN Device Id: 0 000000 000000000
Firmware Version: Q0707A
User Capacity:    31,675,383,808 bytes [31.6 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    Solid State Device
Form Factor:      M.2
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ACS-2 (minor revision not indicated)
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Tue Jul 24 18:22:26 2018 CDT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

-- 
newell  N5TNL