Arch Linux

Lemongrass

Member

From: Central Europe

Registered: 2017-03-03

Posts: 59

Boot flag - can I delete that partition? Can I move the boot flag?

Hi there,

I'd like to ask you if I am safe to remove a partition with the boot flag on. Output of several commands:

% sudo fdisk -l
Disk /dev/sda: 465.8 GiB, 500107862016 bytes, 976773168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x759f9286

Device     Boot     Start       End   Sectors   Size Id Type
/dev/sda1            2048  61442047  61440000  29.3G 83 Linux
/dev/sda2       122884094 976773119 853889026 407.2G  5 Extended
/dev/sda3  *     61442048 122882047  61440000  29.3G 83 Linux
/dev/sda5       184324096 956293119 771969024 368.1G 83 Linux
/dev/sda6       956295168 976773119  20477952   9.8G 82 Linux swap / Solaris
/dev/sda7       122886144 184322047  61435904  29.3G 83 Linux

Partition 2 does not start on physical sector boundary.
Partition table entries are not in disk order.

% df -h
Filesystem      Size  Used Avail Use% Mounted on
dev             3.9G     0  3.9G   0% /dev
run             3.9G  1.1M  3.9G   1% /run
/dev/sda1        29G   14G   15G  48% /
tmpfs           3.9G   11M  3.9G   1% /dev/shm
tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup
tmpfs           3.9G  5.7M  3.9G   1% /tmp
/dev/sda5       363G  203G  141G  60% /mnt/adatok
tmpfs           790M   16K  790M   1% /run/user/1000

% sudo parted --list
Model: ATA WDC WD5000LPVX-7 (scsi)
Disk /dev/sda: 500GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type      File system     Flags
 1      1049kB  31.5GB  31.5GB  primary   ext4
 3      31.5GB  62.9GB  31.5GB  primary   ext4            boot
 2      62.9GB  500GB   437GB   extended
 7      62.9GB  94.4GB  31.5GB  logical   ext4
 5      94.4GB  490GB   395GB   logical   ext4
 6      490GB   500GB   10.5GB  logical   linux-swap(v1)

Additional info:

I have 3 GNU/Linux OS-es installed, namely:

sda1 holds my Arch install that I'm currently using.
sda3 is Debian, that has been there for the most time of the 3 OS-es
sda7 is a Manjaro install that refuses to boot.
sda5 is a big data partition and sda6 is swap.

The order which I used to install these OS-es: first Linux Mint on sda1, then Debian on sda3, then Manjaro on sda7, then replaced Linux Mint with Arch on sda1 (using os-prober) and now I feel that I don't really need Debian or Manjaro on this computer anymore. I guess this is the right order.

Still, the boot flag seems to be present on sda3 (Debian partition).

My OS-es are installed in Legacy mode using GRUB(2).

Can I safely remove those 2 partitions and not break my Arch install? If not, is there any other way I can do this? Thank you in advance.

I guess I ran the

grub-mkconfig -o /boot/grub/grub.cfg

command from Arch hoping it will move that boot flag but it seems it didn't.

EDIT: I fixed code brackets.

Last edited by Lemongrass (2017-06-06 15:03:31)

paulkerry

Member

From: Sheffield, UK

Registered: 2014-10-02

Posts: 611

Re: Boot flag - can I delete that partition? Can I move the boot flag?

Yes you can, but some systems need a boot flag enabled otherwise you can get boot errors.

You can toggle a boot flag within fdisk using the "a" key, which then asks for the partition number to toggle - just "fdisk /dev/sda" and use "a" to toggle 3 off and same again to toggle 1 on, "p" to print and "w" to write.

You shouldn't have any problems, but if so just boot the install media from USB and fix. You might also want to reclaim the lost space from those unused partitions using something like gparted booted from USB.

trytipARCH

Banned

Registered: 2017-06-05

Posts: 38

Re: Boot flag - can I delete that partition? Can I move the boot flag?

...

Last edited by trytipARCH (2017-06-11 03:54:00)

Trilby

Inspector Parrot

Registered: 2011-11-29

Posts: 29,546

Website

Re: Boot flag - can I delete that partition? Can I move the boot flag?

Somewhat off-topic: trytip, you may want to use font-colors more sparringly - those colors can be very hard to read on some of the forum themes/skins.  You can use [ code ] tags for commands and output.

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"UNIX is simple and coherent..." - Dennis Ritchie, "GNU's Not UNIX" -  Richard Stallman