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I am in doubt whether I have partitioned my hdd correctly as GPT on a BIOS motherboard. I used gparted to partition and I don't know if I aligned the beginning/end of the disk correctly, used correct flags etc. The disk in question is sdc:

    $ sudo lsblk -f
NAME   FSTYPE LABEL           MOUNTPOINT
sda                           
├─sda1 ntfs   System Reserved 
├─sda2 ntfs   win7            
└─sda3 ntfs   WINYANCI        
sdb                           
├─sdb1                        
└─sdb5 ext4   YAHSI           
sdc                           
├─sdc1                        
├─sdc2 swap                   [SWAP]
├─sdc3 ext4                   /
├─sdc4 ext4                   /home
├─sdc5 ext4   store1          
└─sdc6 ntfs   store2          
sdd                           
├─sdd1                        
├─sdd2 ntfs   DEPO            
└─sdd5 ntfs   HUSUSI          
sr0  

here is what gdisk shows:

$ sudo gdisk /dev/sdc
GPT fdisk (gdisk) version 0.8.8

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): p
Disk /dev/sdc: 1953525168 sectors, 931.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 2758BB06-C7E7-451B-9C92-F1B278721BB6
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1953525134
Partitions will be aligned on 2048-sector boundaries
Total free space is 3437 sectors (1.7 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048            6143   2.0 MiB     EF02  
   2            6144         8394751   4.0 GiB     8200  
   3         8394752        76754943   32.6 GiB    EF00  
   4        76754944       174409727   46.6 GiB    0700  
   5       174409728      1346283519   558.8 GiB   0700  
   6      1346283520      1953523711   289.6 GiB   0700  

and parted shows this.

Are there any mistakes?

2

To check if all partitions are properly aligned to 1MiB you should divide the start sector by 8. Let's see:

1346283520/8=168285440
174409728/8=21801216
76754944/8=9594368
8394752/8=1049344
6144/8=768
2048/8=256

It looks good. The next thing is to check if the size of the partitions can also be divided by 8:

(1953523711−1346283520+1)/8=75905024
(1346283519−174409728+1)/8=146484224
(174409727−76754944+1)/8=12206848
(76754943−8394752+1)/8=8545024
(8394751−6144+1)/8=1048576
(6143−2048+1)/8=512

It also looks good. You divide by 8 because of the technology called "advanced format". Just look at the following images:

enter image description here

enter image description here

But this concerns only disks that have this feature. If you don't have a disk with the "advanced format" technology, it doesn't matter what alignment you use. Most of modern disks use this thing, and most of partition tools align partitions to 1MiB by default.

  • What about the EF00 flag of sdc3 (my / partition). I have no EFI but it's marked as an EFI System? PS: I do have "advanced format" on sdc, that's why I bothered with GPT :) – şaloma Feb 20 '14 at 6:39
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    If you have a disk which size is <2GiB, you don't have to use GPT. "Advanced format" just means that system uses 8 sectors instead of one, and that's it. As for the EF00 flag, I think you should ask another question. – Mikhail Morfikov Feb 20 '14 at 6:57
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    I probably should have asked another question about the flags (or types as gdisk calls them) but I have figured what was wrong with them: apparently gparted doesn't correctly use them. I fixed them using cgdisk. I changed EF00 to 8300 as it is an Linux partition not an EFI. – şaloma Feb 20 '14 at 9:52

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