-
Starnge dd behaviour in 8.2.0
Dear All -
If I use the command fdisk -l I get the usual and expected output of the style
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 131604479 131602432 62.8G 7 HPFS/NTFS/exFAT
/dev/sda2 131604480 1180327679 1048723200 500.1G 7 HPFS/NTFS/exFAT
/dev/sda3 1180327680 2229050879 1048723200 500.1G 7 HPFS/NTFS/exFAT
My question concerns the line
/dev/sda1 * 2048 131604479 131602432 62.8G 7 HPFS/NTFS/exFAT
Surely that means that /dev/sda1 starts at sector number 2048 and that there are 2,048 sectors at the start of /dev/sda (yes, numbered 0000-2047) allocated otherwise?
For various reasons I want to zero these initial sectors of /dev/sda using the command
dd if=/dev/zero of=/dev/sda count=2048
but to my annoyance (and very considerable damage to the system) this also zeroes the first sector of /dev/sda1.
That is, the dd command zeroes not just those sectors numbered 0000-2047 but also the sector numbered 2048: so 2049 altogether. not 2048.
I am absolutely convinced that my understanding of counts / numbers / numbering as described above was correct under 7.4.2 and that I issued commands, many times, in the manner describe without damaging /dev/sda1; (but I am a bit nervous now about checking that)!
Can anybody conform that I am right? That I am wrong? That dd under 8.2.0 is glitchy?
Thank you!
Fergus
PS And by the way (completely different and unconnected) I find the file /boot/isolinux/ifcpu64.c32 is broken in the 8.2.0 installation and I have to over-write it with the same file from 7.4.2 for things to work properly. Anybody else?
Fergus
Posting Permissions
- You may not post new threads
- You may not post replies
- You may not post attachments
- You may not edit your posts
-
Forum Rules
CSE-118 Supermicro 1U 3x GPU Server 2.6Ghz 20-C 128GB CX353A 2x1600W PSU Rails
$454.03
Dell PowerEdge R630 8SFF 2.6Ghz 20-Core 128GB Mem 2x10G+2x1G NIC 2x750W PSU
$399.04
Supermicro 4U 36 Bay Storage Server 2.2Ghz 16-C 128GB 1x1280W Rails TrueNAS ZFS
$725.06
CSE-118 Supermicro 1U GPU Server 2.6Ghz 28-C 128GB 2x Nvidia K40 GPU 2x1600W PSU
$580.03
Intel Xeon E5-2680 v4 2.4GHz 35MB 14-Core 120W LGA2011-3 SR2N7
$17.99
Intel Xeon Gold 6140 SR3AX 2.3GHz 18-Core Processor CPU
$44.99
INTEL XEON GOLD 6148 2.40 GHz SR3B6 CPU
$98.99
HP Z4G4 Intel Xeon W2133-3.6 GHz, 256 NVME, 6TB HDD, 32GB RAM P620 NO OS
$265.00
Dell Precision T5600/t5610 Xeon E5-2670 2.6Ghz 16GB DDR3 RAM NO HDD Nvidia
$85.50
DELL PowerEdge R730 Server 2x E5-2690v3 2.6GHz =24 Cores 32GB H730 4xRJ45
$274.00