Created
August 8, 2020 21:22
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wipe head and tail of a block device
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| #!/bin/bash | |
| set -e | |
| # wipe first and last 10MiB | |
| SECTORS_WIPE=20480 | |
| # ensure $1 is block device | |
| test -b $1 | |
| # get number of 512-byte sectors | |
| sectors=$(blockdev --getsz $1) | |
| # check size constraints | |
| test "$sectors" -gt "$SECTORS_WIPE" | |
| tailSeek=$(($sectors - $SECTORS_WIPE)) | |
| # display disk information | |
| lsblk -o NAME,SIZE,TYPE,VENDOR,MODEL,REV,SERIAL,STATE $1 | |
| # display actions | |
| printf "\nWiping $1...\nTotal 512-byte sectors: $sectors\nWiping 0-$SECTORS_WIPE, $tailSeek-$sectors\n\n" | |
| # prompt for user confirmation | |
| read -p "Proceed? [y/N] " -n 1 -r proceed | |
| echo | |
| test "y$proceed" != "yy" && test "y$proceed" != "yY" && echo "Aborted." && exit | |
| printf "\n1: Write random to head\n"; date | |
| echo dd if=/dev/urandom of=$1 count=$SECTORS_WIPE | |
| dd if=/dev/urandom of=$1 count=$SECTORS_WIPE | |
| printf "\n2: Write zeroes to head\n"; date | |
| echo dd if=/dev/zero of=$1 count=$SECTORS_WIPE | |
| dd if=/dev/zero of=$1 count=$SECTORS_WIPE | |
| printf "\n3: Write random to tail\n"; date | |
| echo dd if=/dev/urandom of=$1 seek=$tailSeek count=$SECTORS_WIPE | |
| dd if=/dev/urandom of=$1 seek=$tailSeek count=$SECTORS_WIPE | |
| printf "\n4: Write zeroes to tail\n"; date | |
| echo dd if=/dev/zero of=$1 seek=$tailSeek count=$SECTORS_WIPE | |
| dd if=/dev/zero of=$1 seek=$tailSeek count=$SECTORS_WIPE |
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