Changes for page Effacer la signature d'un périphérique avec wipefs
Last modified by Mélodie on 2026/07/11 13:38
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... ... @@ -61,7 +61,6 @@ 61 61 {{/code}} 62 62 {{/info}} 63 63 64 -(% class="wikigeneratedid" %) 65 65 66 66 67 67 === 3. Check the partition table type and the presence of signatures === ... ... @@ -108,7 +108,6 @@ 108 108 ##wipefs -a## is preferable to a blind ##dd if=/dev/zero of=/dev/sdX##: the latter overwrites the entire device (slower, riskier if ##count## isn't carefully controlled), whereas ##wipefs## targets precisely the identified signatures, wherever they are on the disk — including a signature at the end of the disk, as in the GPT remnant case mentioned earlier. 109 109 {{/info}} 110 110 111 -(% class="wikigeneratedid" %) 112 112 113 113 114 114 === 6. Force the kernel to reread the partition table === ... ... @@ -124,7 +124,7 @@ 124 124 Without this step, the system may still display a cached state during the next verification, rather than the device's actual state after cleanup. 125 125 126 126 127 -=== 7. Verifythat the cleanupwas effective===125 +=== 7. Check effectiveness of the cleanup === 128 128 129 129 With administrator privileges: 130 130 ... ... @@ -132,9 +132,25 @@ 132 132 blkid -p /dev/sdX 133 133 {{/code}} 134 134 135 - Shouldn't return anything (or only the device's generic information): a sign that the device is now on a clean footing (##/dev/sdX## should still be adapted).133 +##/dev/sdX## should still be adapted. 136 136 135 +Should return nothing (or only the device's generic information): a sign that the device is now on a clean footing. 137 137 137 +In addition, it's possible to inspect the raw bytes of the first sector directly: 138 + 139 +{{code language="bash"}} 140 +hexdump -C -n 512 /dev/sdX | tail -n 2 141 +{{/code}} 142 + 143 +or, equivalently: 144 + 145 +{{code language="bash"}} 146 +xxd -l 512 /dev/sdX | tail -n 2 147 +{{/code}} 148 + 149 +Once the new partition table has been created, the boot sector's end-of-sector signature (##55 aa##, at bytes 510-511) should be present. This signature is universal: it appears on both a ##dos## table and a ##gpt## table, the latter always starting with a "protective MBR" in the first sector, itself ending with the ##55 aa## signature as well. Its presence is simply an indicator of consistency in the first sector, regardless of the partition table type in use. 150 + 151 + 138 138 === 8. Repartition === 139 139 140 140 ... ... @@ -145,7 +145,6 @@ 145 145 If the end goal is to install Ventoy on the stick: it is recommended to create the partition table with GParted **before** launching the Ventoy installer, rather than letting it manage the entire disk on its own. This makes it possible to explicitly choose MS-DOS or GPT depending on the target machine, useful for instance when facing a hybrid BIOS/UEFI that will only boot from an MS-DOS table. Ventoy also offers its own option for this choice (##-g## for GPT, MBR by default); see the documentation on [[ventoy.net>>https://ventoy.net]] and in the program's README, for installation details. 146 146 {{/info}} 147 147 148 -(% class="wikigeneratedid" %) 149 149 150 150 151 151 == Key takeaway ==