Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #166523 > unrolled thread

debian installer 4k sectors

Started byPavel Kosina <peekaa@email.cz>
First post2016-04-08 08:50 +0200
Last post2016-04-08 11:00 +0200
Articles 7 — 6 participants

Back to article view | Back to linux.debian.user

Contents

  debian installer 4k sectors Pavel Kosina <peekaa@email.cz> - 2016-04-08 08:50 +0200
    Re: debian installer 4k sectors Sven Hartge <sven@svenhartge.de> - 2016-04-08 10:10 +0200
      Re: debian installer 4k sectors <peekaa@email.cz> - 2016-04-08 10:30 +0200
        Re: debian installer 4k sectors Sven Hartge <sven@svenhartge.de> - 2016-04-08 11:10 +0200
      Re: debian installer 4k sectors Curt <curty@free.fr> - 2016-04-08 11:00 +0200
    Re: debian installer 4k sectors cbannister@slingshot.co.nz - 2016-04-08 10:30 +0200
    Re: debian installer 4k sectors Felix Miata <mrmazda@earthlink.net> - 2016-04-08 11:00 +0200

#166523 — debian installer 4k sectors

FromPavel Kosina <peekaa@email.cz>
Date2016-04-08 08:50 +0200
Subjectdebian installer 4k sectors
Message-ID<rlyoW-8fi-15@gated-at.bofh.it>
Hi,

several times I tried install Debian stable/testing. I have MB Asrock 
UEFI D1800B-ITX and HDD WD20EFRX. Debian installer /part where 
partitioning and formatting happens/ never formats to correct sectors 
4k. It always formats to 512b:
----------------------
linuxbox:~# fdisk -l
Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 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: 0xa10b2c0d

Device     Boot      Start        End    Sectors  Size Id Type
/dev/sda1  *          2048 3903531007 3903528960  1.8T 83 Linux
/dev/sda2       3903533054 3907028991    3495938  1.7G  5 Extended
/dev/sda5       3903533056 3907028991    3495936  1.7G 82 Linux swap / 
Solaris

Partition 2 does not start on physical sector boundary.
-----------------------------


why is that? Is that bug or I miss something?
Due to this there is also error: "Partition 2 does not start on physical 
sector boundary."

Thank you
Pavel

[toc] | [next] | [standalone]

#166524

FromSven Hartge <sven@svenhartge.de>
Date2016-04-08 10:10 +0200
Message-ID<rlzEm-Px-19@gated-at.bofh.it>
In reply to#166523
Pavel Kosina <peekaa@email.cz> wrote:

> several times I tried install Debian stable/testing. I have MB Asrock 
> UEFI D1800B-ITX and HDD WD20EFRX. Debian installer /part where 
> partitioning and formatting happens/ never formats to correct sectors 
> 4k. It always formats to 512b:
> ----------------------
> linuxbox:~# fdisk -l
> Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 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: 0xa10b2c0d

> Device     Boot      Start        End    Sectors  Size Id Type
> /dev/sda1  *          2048 3903531007 3903528960  1.8T 83 Linux
> /dev/sda2       3903533054 3907028991    3495938  1.7G  5 Extended
> /dev/sda5       3903533056 3907028991    3495936  1.7G 82 Linux swap / 
> Solaris

> Partition 2 does not start on physical sector boundary.
> -----------------------------
> why is that? Is that bug or I miss something?

Partition 2 is the Extended Partition, which is only a container for
logical partitions. The extended partition does not need to be aligned
with the 4096 sector size. Partition 5, the first logical partition,
which contains the real file system needs to be aligned and it is:
3903533056/4096=953011.

> Due to this there is also error: "Partition 2 does not start on physical 
> sector boundary."

This is, because fdisk is a bit dumb in that context.

Everything is fine and correctly aligned.

Grüße,
Sven.

-- 
Sigmentation fault. Core dumped.

[toc] | [prev] | [next] | [standalone]

#166527

From<peekaa@email.cz>
Date2016-04-08 10:30 +0200
Message-ID<rlzXI-XP-21@gated-at.bofh.it>
In reply to#166524

[Multipart message — attachments visible in raw view] — view raw

Thank you. And what about logical sector 512b? Is that also bug in fdisk? 
Pavel



---------- Původní zpráva ----------
Od: Sven Hartge <sven@svenhartge.de>
Komu: debian-user@lists.debian.org
Datum: 8. 4. 2016 10:02:39
Předmět: Re: debian installer 4k sectors

"Pavel Kosina <peekaa@email.cz> wrote:

> several times I tried install Debian stable/testing. I have MB Asrock 
> UEFI D1800B-ITX and HDD WD20EFRX. Debian installer /part where 
> partitioning and formatting happens/ never formats to correct sectors 
> 4k. It always formats to 512b:
> ----------------------
> linuxbox:~# fdisk -l
> Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 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: 0xa10b2c0d

> Device Boot Start End Sectors Size Id Type
> /dev/sda1 * 2048 3903531007 3903528960 1.8T 83 Linux
> /dev/sda2 3903533054 3907028991 3495938 1.7G 5 Extended
> /dev/sda5 3903533056 3907028991 3495936 1.7G 82 Linux swap / 
> Solaris

> Partition 2 does not start on physical sector boundary.
> -----------------------------
> why is that? Is that bug or I miss something?

Partition 2 is the Extended Partition, which is only a container for
logical partitions. The extended partition does not need to be aligned
with the 4096 sector size. Partition 5, the first logical partition,
which contains the real file system needs to be aligned and it is:
3903533056/4096=953011.

> Due to this there is also error: "Partition 2 does not start on physical 
> sector boundary."

This is, because fdisk is a bit dumb in that context.

Everything is fine and correctly aligned.

Grüße,
Sven.

-- 
Sigmentation fault. Core dumped."

[toc] | [prev] | [next] | [standalone]

#166531

FromSven Hartge <sven@svenhartge.de>
Date2016-04-08 11:10 +0200
Message-ID<rlAAq-1tY-27@gated-at.bofh.it>
In reply to#166527
peekaa@email.cz wrote:

> Thank you. And what about logical sector 512b? Is that also bug in fdisk? 

No. That is how your harddrive presents itself to the world. It uses
internal 4k sectors but the interface to the outside world uses 512b
sectors. Most disks do this for greater compatibility with legacy
operating systems.

Grüße,
Sven.

-- 
Sigmentation fault. Core dumped.

[toc] | [prev] | [next] | [standalone]

#166529

FromCurt <curty@free.fr>
Date2016-04-08 11:00 +0200
Message-ID<rlAqK-1ai-1@gated-at.bofh.it>
In reply to#166524
On 2016-04-08, Sven Hartge <sven@svenhartge.de> wrote:
>
> Partition 2 is the Extended Partition, which is only a container for
> logical partitions. The extended partition does not need to be aligned
> with the 4096 sector size. Partition 5, the first logical partition,
> which contains the real file system needs to be aligned and it is:
> 3903533056/4096=953011.
>
>> Due to this there is also error: "Partition 2 does not start on physical 
>> sector boundary."
>
> This is, because fdisk is a bit dumb in that context.

The Gnome Disk Utility is also dumb in this sense and gives a warning
for the extended partition, claiming misalignment and suggesting
repartitioning.

> Everything is fine and correctly aligned.
>
> Grüße,
> Sven.
>


-- 
Hypertext--or should I say the ideology of hypertext?--is ultrademocratic and
so entirely in harmony with the demagogic appeals to cultural democracy that
accompany (and distract one’s attention from) the ever-tightening grip of 
plutocratic capitalism. - Susan Sontag

[toc] | [prev] | [next] | [standalone]

#166526

Fromcbannister@slingshot.co.nz
Date2016-04-08 10:30 +0200
Message-ID<rlzXH-XP-5@gated-at.bofh.it>
In reply to#166523
On Fri, Apr 08, 2016 at 08:36:50AM +0200, Pavel Kosina wrote:
> Hi,
> 
> several times I tried install Debian stable/testing. I have MB Asrock UEFI
> D1800B-ITX and HDD WD20EFRX. Debian installer /part where partitioning and
> formatting happens/ never formats to correct sectors 4k. It always formats
> to 512b:
> ----------------------
> linuxbox:~# fdisk -l
> Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 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: 0xa10b2c0d
> 
> Device     Boot      Start        End    Sectors  Size Id Type
> /dev/sda1  *          2048 3903531007 3903528960  1.8T 83 Linux
> /dev/sda2       3903533054 3907028991    3495938  1.7G  5 Extended
> /dev/sda5       3903533056 3907028991    3495936  1.7G 82 Linux swap /
> Solaris
> 
> Partition 2 does not start on physical sector boundary.
> -----------------------------
> 
> 
> why is that? Is that bug or I miss something?
> Due to this there is also error: "Partition 2 does not start on physical
> sector boundary."

Sorry I don't have the answer, but:
https://wiki.archlinux.org/index.php/Advanced_Format
shows the HDD WD20EFRX to be logical 512 and physical 4096

and
http://excess.org/article/2010/11/wd-hdd-lying-about-4k-sectors/

It seems the first partition is aligned correctly. 

Hopefully the answer isn't "you have to calculate the sector alignment 
yourself and physically enter those values."

-- 
The media's the most powerful entity on earth. 
They have the power to make the innocent guilty 
and to make the guilty innocent, and that's power.
 -- Malcolm X

[toc] | [prev] | [next] | [standalone]

#166530

FromFelix Miata <mrmazda@earthlink.net>
Date2016-04-08 11:00 +0200
Message-ID<rlAqK-1ai-19@gated-at.bofh.it>
In reply to#166523
Pavel Kosina composed on 2016-04-08 08:36 (UTC+0200):

> several times I tried install Debian stable/testing. I have MB Asrock
> UEFI D1800B-ITX and HDD WD20EFRX. Debian installer /part where
> partitioning and formatting happens/ never formats to correct sectors
> 4k. It always formats to 512b:

Hard disks now have 4k sectors, but PC and Mac operating systems do not. It 
will probably still be quite some time, if ever, before software stops 
defining a sector as 512b.

Hard disks transparently convert software (logical) sectors of 512b to 4k 
internally. Smarter kernels, drivers and partitioning applications take this 
need to convert into account, aligning reads and writes as much as possible 
to minimize the need for internal conversion, primarily by using I/O block 
sizes of 4k (8 512b sectors) or some multiple thereof, especially when 
partitions are being created. By doing so, the internal overhead is 
eliminated or minimized, maximizing I/O performance.

How this works and more is explained at:
http://www.seagate.com/tech-insights/advanced-format-4k-sector-hard-drives-master-ti/

> ----------------------
> linuxbox:~# fdisk -l
> Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 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: 0xa10b2c0d

> Device     Boot      Start        End    Sectors  Size Id Type
> /dev/sda1  *          2048 3903531007 3903528960  1.8T 83 Linux
> /dev/sda2       3903533054 3907028991    3495938  1.7G  5 Extended
> /dev/sda5       3903533056 3907028991    3495936  1.7G 82 Linux swap /
> Solaris

> Partition 2 does not start on physical sector boundary.
> -----------------------------

> why is that? Is that bug or I miss something?

As noted by others, it mostly amounts to a cosmetic bug, but it can cause 
other partitioning programs to report corruption of the table and refuse to 
function, or even recognize the existence of partitions existing already.

> Due to this there is also error: "Partition 2 does not start on physical
> sector boundary."

Software other than partitioners is more accommodating than partitioning 
tools about this "error". The kernel and disk drivers are not affected by this.

You do have the option to partition in advance with a tool of your choice, 
and simply direct the installer which partitions to mount where. I always do.
-- 
"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/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.debian.user

csiph-web