At Mon, 14 Sep 2020 13:14:44 -0700 CentOS mailing list <centos at 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 at centos.org > https://lists.centos.org/mailman/listinfo/centos > > > -- Robert Heller -- Cell: 413-658-7953 GV: 978-633-5364 Deepwoods Software -- Custom Software Services http://www.deepsoft.com/ -- Linux Administration Services heller at deepsoft.com -- Webhosting Services