EFI disk labeling / understand the parition table / sectors not continue
Hi all,
I have a EFI disk and it is use in zfs pool.
It mentioned that there are total of (a)1172107117 + (b)16384 = 1172123501 sectors (c)
Partition 8 = 1172107151 to 1172123534 = 16384 sectors which match (b)
Partition 0 = 256 to 1172107150 = 1172106895 sectors which dont match (a)
Addup the sectors in the 2 partitions
which is <= to the total sectors (1172123501) (c)
If i say partition 0 = first sector 0 to 1172107150 which addup to 1172107151 sectors which is then even more then 1172107117 (a)
How it all adds-up ?
Where are all the missing or extra sectors ?
fdisk is reporting 512 bytes sectors but nowadays, disks have 4096 bytes sectors.
The discrepancy between the available size (1172107117 x 512 bytes sectors) and the amount actually used (1172107151 x 512 bytes sectors) is 34 sectors, i.e. 4.25 (sic) actual sectors.
So you have 0.0000029 % of the disk unusable due to rounding errors. No big deal.
Last edited by jlliagre; 01-14-2019 at 02:38 PM..
These 2 Users Gave Thanks to jlliagre For This Post:
fdisk is reporting 512 bytes sectors but nowadays, disks have 4096 bytes sectors.
The discrepancy between the available size (1172107117 x 512 bytes sectors) and the amount actually used (1172107151 x 512 bytes sectors) is 34 sectors, i.e. 4.25 (sic) actual sectors.
So you have 0.0000029 % of the disk unusable due to rounding errors. No big deal.
Hi jlliagre,
Thanks for taking this up.
q1) what do you mean by "4.25 (sic) actual sectors." ? Where the 4.25 ?
q2) 1172107151 > did you count from 0 to 1172107150 ? (as the partition starts from 256 -> probably due to alignment set by Oracle)
q1: There are 34 sectors of 512 bytes, but, assuming 4096 bytes actual sectors, that makes 34 * 512 / 4096 = 4.25 sectors (of 4096 bytes each).
q2: Yes I did.
Hi jlliagre,
Thanks for the confirmation. I am sorry to ask, i got a 6.4 SSD but just appear to be 5.82TB usable.
Using auto-configure, the partition table look as below.
From 0 to 12502430343 in partition 0, the amount of sectors 12502430344 seems to be more then the total available sectors 12502430317
Still got no idea where did i lost my 800GB of space...
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i'm writing some code to simulate the boot progress after power on
but when i try to read the 2nd sector from a floppy disk, this operation always fail with ah=0x80h which means timeout, how can i get over this problem?
my code would be like this:
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#define SETUPLEN 4... (0 Replies)
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my code would be like this:
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.code16
#define SETUPLEN 4... (0 Replies)
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#----------------------
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