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PhilR
Asked: 2021-07-27 11:54:33 +0800 CST

Show free SSD space after TRIM / UNMAP / Deallocate?

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For a hard drive supporting ATA TRIM, SCSI UNMAP, or NVMe Deallocate, is it possible to report on the amount of unallocated space?

For example, we take a 1TB drive, then write 500GB data to it, then delete 300GB. Is there any command to show that the drive itself (not the filesystem) has 200GB used / 800GB free?

ssd nvme trim

1 Answers

  1. On my nvme ssd, smartctl -a /dev/nvme0n1 reports

    Number of Namespaces:               1
Namespace 1 Size/Capacity:          2.048.408.248.320 [2,04 TB]
Namespace 1 Utilization:            352.739.127.296 [352 GB]
Namespace 1 Formatted LBA Size:     512
Namespace 1 IEEE EUI-64:            002538 b211b408d5

    I couldn't find a way to see this for sata ssds.

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