At Mon, 14 Sep 2020 13:14:44 -0700 CentOS mailing list centos@centos.org wrote:
Folks
I've encountered situations where I want to reuse a hard-drive. I do not want to preserve anything on the drive, and I'm not concerned about 'securely erasing' old content. I just want to be able to define it as an Physical Volume (in a logical volume set), or make it a ZFS disk, or sometimes make it a simple EXT3, ExFAT or NTFS disk. However, old 'signatures' get in the way and Linux sometimes refuses to let me proceed. I know that a fool-proof solution is to use the "dd if=/dev/zero bs=32768 oflag=direct" on the disk, but when we're talking USB-connected hard drives of 8 TB, that's an operation that can take days.
The disk in question might even have been corrupted. This would make using 'zpool destroy' to clear out a ZFS disk, or
I've tried erasing the first megabyte of the disk, but there are ZFS or LVM structures that get in the way. So, does anyone have an efficient way to erase structures from a disk such that it can be reused?
Something like -erase first N blocks (block defined as 4096)
- Erase <number> blocks starting at block <number>
- erase last <number> blocks
Use dd in a script:
#!/bin/bash # erase N 4K blocks starting at M # (M=0 means from the start of the disk) # usage: $0 start4Kblock numberof4Kblocks drive M = $1 N = $2 rawdisk = $3 dd if=/dev/zero bs=4096 oflag=direct count=$N seek=$M of=$rawdisk
At least such an algorithm would be quicker than erasing 8 TB of data.
David
CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos