Re: MBR partitioning, and content after partition table but before first partition
- Date: Thu, 9 Mar 2017 01:56:34 -0500
- From: Felix Miata <mrmazda@xxxxxxxxxxxxx>
- Subject: Re: MBR partitioning, and content after partition table but before first partition
David Christensen composed on 2017-03-08 21:46 (UTC-0800):
Examining a Jesse system drive, the first partition starts at block 2048
(1 MB = 2**20 bytes):
2017-03-08 21:30:04 root@jesse ~
# parted /dev/sda u s p
Model: ATA SAMSUNG SSD UM41 (scsi)
Disk /dev/sda: 31277232s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 2048s 976895s 974848s primary ext4 boot
2 976896s 1953791s 976896s primary
3 1953792s 28125183s 26171392s primary
There is content in the first 101 blocks (1 MBR plus 100 other):
2017-03-08 21:30:06 root@jesse ~
# dd if=/dev/sda count=2048 2>/dev/null | hexdump -C | tail
What is in blocks 1-101?
Was that disk ever used for anything besides Jessie, not new or wiped first?
Run strings on it or view in a sector editor and you'll probably see grub
somewhere, if it's a typical Linux installation that puts Grub in the MBR
instead of on a primary partition with its boot flag set, along with generic
code in the MBR.
Occasionally some of those sectors are used for RAID.
"The wise are known for their understanding, and pleasant
words are persuasive." Proverbs 16:21 (New Living Translation)
Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!
Felix Miata *** http://fm.no-ip.com/