[SOLVED] fdisk structure of my disk - is it normal?

maboleth · 2020-01-11 20:39:35

Disk /dev/sda: 1,84 TiB, 2000398934016 bytes, 3907029168 sectors
Disk model: WDC WD2003FZEX-0
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: gpt
Disk identifier: BCBC009E-4EA9-41D7-9E3A-E6D9BD94F36D

Device          Start        End    Sectors   Size Type
/dev/sda1          34      32767      32734    16M Microsoft reserved
/dev/sda2       32768 1953529855 1953497088 931,5G Microsoft basic data
/dev/sda3  1953529856 3907028991 1953499136 931,5G Linux filesystem

Partition 1 does not start on physical sector boundary.

I'm re-making the partitions from NTFS to Ext4, backuping and copying stuff again. However, I have noticed this line in red - Partition 1 does not start on physical sector boundary. - What does it mean? Disk was formatted by Win10 the first time.

So my questions are:

1. Should I delete both sda1 & sda2 and merge it into a single ext4?
2. Anything to do/check for this Partition 1 message? Or let Gparted do the job?

Thanks.

Last edited by maboleth (2020-01-12 12:22:22)

graysky · 2020-01-11 20:52:18

micro$oft silliness. I honestly don't kow but sda2 starts on a power of 2 at least. Probably fine.

EDIT: wait, are you demicro$ofting the disk? If so, yes, I would remove both sda1 and sda2 an just make a new sda1 then resort partitions. Also, unless you don't have another disk, don't resize in my opinion. Copy data off, repartition, copy back.

Last edited by graysky (2020-01-11 20:53:46)

maboleth · 2020-01-11 21:08:44

graysky wrote:

micro$oft silliness. I honestly don't kow but sda2 starts on a power of 2 at least. Probably fine.
EDIT: wait, are you demicro$ofting the disk? If so, yes, I would remove both sda1 and sda2 an just make a new sda1 then resort partitions. Also, unless you don't have another disk, don't resize in my opinion. Copy data off, repartition, copy back.

xD Yes, I'm demicrosofting the disk! I want to reduce W10 to bare minimum. This is my 2nd disk in the system and not a bootable one.

So yeah, that's what I wanted to do - I'm doing a backup now, then gparted, merging of sda1-2 and making an ext4.

But what about that message? Partition 1 does not start on physical sector boundary. Will that disappear when I delete those two partitions?

seth · 2020-01-11 21:34:59

Sector size (logical/physical): 512 bytes / 4096 bytes
…
Device          Start        End    Sectors   Size Type
/dev/sda1          34      32767      32734    16M Microsoft reserved

echo '512*34/4096' | bc -l
echo '512*2048/4096' | bc -l # fdisk will by default put the first partition there

graysky · 2020-01-11 22:40:39

Again, I am recommending against using a resize. Just copy data off, delete those partitions, make a new one, reorder them, copy back data.. Partitioning should be like 20 seconds and you're done once data are saved. Also, the tool (fdisk) will align automatically.

maboleth · 2020-01-11 23:03:33

graysky wrote:

Again, I am recommending against using a resize. Just copy data off, delete those partitions, make a new one, reorder them, copy back data.. Partitioning should be like 20 seconds and you're done once data are saved. Also, the tool (fdisk) will align automatically.

Just curious, but why are you against resizing? I used it so many times without any issues on both ext4 and ntfs?

I now did everything but I'm thinking whether to delete one partition I just created and just resize it to have the entire 2T drive as a single partition.

Update: I won't... it's easier to backup as 1t+1t drive.

Last edited by maboleth (2020-01-11 23:35:16)

graysky · 2020-01-12 00:02:47

Unnecessary since you have 2 discs with backup already...

maboleth · 2020-01-12 00:16:44

I have 1 external disc for backup and it's 1T. So I'm a bit short on space, so 1t+1t partitions are easier to manage for me in case of any change.

Anyway, glad this all went well! :-) Thanks!

maboleth · 2020-01-12 00:26:46

Speaking of copying/backuping from external USB 3.0 drive, I have also noticed I get little bit higher MB/s by just dragging and dropping dirs via Nautilus. It's about 100-120MB/s while Rsync is about 85-95MB. Not sure why.

Last edited by maboleth (2020-01-12 00:30:34)

mxfm · 2020-01-12 06:13:59

maboleth wrote:

But what about that message? Partition 1 does not start on physical sector boundary. Will that disappear when I delete those two partitions?

It is documented in the wiki at multiple places and here. For modern disk it is optimal to align beginning of partition on 4096 bytes boundary.

There is exception to this rule because this type of partitions are used once on boot and do no not impact on performance. I don't know why Microsoft decided to create this partition - probably it is bootloader code or just a dumb partition created to align next partitions properly (what is in there?). Obviously, if such kind of partitions are removed, the warning message will disappear.

TL;dr the warning is relevant only if 'core' partitions (root, home and other data) are not aligned properly. In your case all partitions after sda1 are aligned properly, so there is no problem.

darkrocket · 2020-01-12 06:43:44

mxfm wrote:

maboleth wrote:
But what about that message? Partition 1 does not start on physical sector boundary. Will that disappear when I delete those two partitions?
It is documented in the wiki at multiple places and here. For modern disk it is optimal to align beginning of partition on 4096 bytes boundary.
There is exception to this rule because this type of partitions are used once on boot and do no not impact on performance. I don't know why Microsoft decided to create this partition - probably it is bootloader code or just a dumb partition created to align next partitions properly (what is in there?). Obviously, if such kind of partitions are removed, the warning message will disappear.
TL;dr the warning is relevant only if 'core' partitions (root, home and other data) are not aligned properly. In your case all partitions after sda1 are aligned properly, so there is no problem.

I did a BIOS/GPT setup yesterday and fdisk didn't allow me to start a partition under the sector 2048 (maybe there is a way but I didn't stop to find it).

liewkj · 2020-01-12 08:47:24

Device          Start        End    Sectors   Size Type
/dev/sda1          34      32767      32734    16M Microsoft reserved

Windows 10 installation will create a dummy 16MB partition to keep enough free blocks to prevent SSD/Flash performance degradation.

The FDISK layout looks awkward. It is GPT partition but without EFI system partition or GRUB bios boot partition. I doubt if the disk is even bootable itself, if you are not booting from USB or CDROM. If you don't care about data in /dev/sda2 or already have a backup, then I would just zap the partition and recreate everything fresh with proper alignment. I don't know if you have planned to keep the Windows OS. (which I guessed it's in /dev/sda2) If it is no longer bootable, then it does not make sense to keep it. Nowadays, you can reinstall Windows 10 fairly easily from official ISO image from Microsoft. ArchLinux installation is so easy and lean. With a good network, getting ArchLinux to boot into terminal is less than 10 mins, and perhaps another 10 mins to bring up GNOME.

maboleth · 2020-01-12 10:20:33

Thanks guys!

Well, now everything seems fine:

Disk /dev/sda: 1,84 TiB, 2000398934016 bytes, 3907029168 sectors
Disk model: WDC WD2003FZEX-0
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: gpt
Disk identifier: BCBC009E-4EA9-41D7-9E3A-E6D9BD94F36D

Device          Start        End    Sectors   Size Type
/dev/sda1        2048 1953529855 1953527808 931,5G Linux filesystem
/dev/sda2  1953529856 3907028991 1953499136 931,5G Linux filesystem

@liewkj this drive wasn't the boot drive. It was a 2nd drive for important files and other data. W10 is on the SSD, as well as Arch itself.

mxfm · 2020-01-12 12:20:30

darkrocket wrote:

I did a BIOS/GPT setup yesterday and fdisk didn't allow me to start a partition under the sector 2048 (maybe there is a way but I didn't stop to find it).

I use gdisk and it is able to create such partitions.

darkrocket wrote:

Thanks guys!
Well, now everything seems fine:

If the issue is resolved mark thread title with [SOLVED].

Last edited by mxfm (2020-01-12 12:21:35)

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#1 2020-01-11 20:39:35

[SOLVED] fdisk structure of my disk - is it normal?

#2 2020-01-11 20:52:18

Re: [SOLVED] fdisk structure of my disk - is it normal?

#3 2020-01-11 21:08:44

Re: [SOLVED] fdisk structure of my disk - is it normal?

#4 2020-01-11 21:34:59

Re: [SOLVED] fdisk structure of my disk - is it normal?

#5 2020-01-11 22:40:39

Re: [SOLVED] fdisk structure of my disk - is it normal?

#6 2020-01-11 23:03:33

Re: [SOLVED] fdisk structure of my disk - is it normal?

#7 2020-01-12 00:02:47

Re: [SOLVED] fdisk structure of my disk - is it normal?

#8 2020-01-12 00:16:44

Re: [SOLVED] fdisk structure of my disk - is it normal?

#9 2020-01-12 00:26:46

Re: [SOLVED] fdisk structure of my disk - is it normal?

#10 2020-01-12 06:13:59

Re: [SOLVED] fdisk structure of my disk - is it normal?

#11 2020-01-12 06:43:44

Re: [SOLVED] fdisk structure of my disk - is it normal?

#12 2020-01-12 08:47:24

Re: [SOLVED] fdisk structure of my disk - is it normal?

#13 2020-01-12 10:20:33

Re: [SOLVED] fdisk structure of my disk - is it normal?

#14 2020-01-12 12:20:30

Re: [SOLVED] fdisk structure of my disk - is it normal?

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