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Confused about the Write Zeroes command
(lemmy.blahaj.zone)
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this post was submitted on 19 Oct 2023
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I am coming at this from a more general angle, so this may not be as applicable.
When a repeated series of inputs is written to a drive, a number of optimisations can be applied. If the user wants a large number of zeros written, the drive's firmware can use a short cut. Instead of writing those zeros, it can make a note that a number of blocks, at a location, are all zero.
This becomes apparent if one runs fio against the raw block devices versus a software later like LVM. Some operations against some layers will be unreasonably fast. There is a lot of nuance to this.
My read of the quirk is an incompatibility between what Linux expects and the firmware. Enable the quirk only if the dmesg errors are present. Do not expect that the drive has been zeroed. If you want your data secure at disposal of the drive, the then use encryption.
Thanks a lot! This clarifies it for me, and if I understand correctly, it shouldn't be a concern for me since my laptop isn't used for data-intensive computing.
What if you try to wipe a NVME-drive for which this quirk is enabled by default in the kernel? Does that mean that even if you used something like the 'erase device' function in GNOME Disks on said drive, it would in fact not actually completely zero the drive? What if you use GNOME Disks to wipe a partition on said drive?
Or does this quirk refer to an entirely different operation?
A bit outside of my knowledge, but I understand that too be a long standing issue. Wiping issues are a good reason to encrypt a NVMe drive.
This page suggest the nvmi-cli has a secure format command that will do it. http://blog.pythonaro.com/2018/05/how-to-securely-wipe-nvme-drive.html?m=1
Hopefully, someone more knowledgeable will also tag me in their response.