From: Erwin van Londen <erwin@erwinvanlonden.net>
To: Johnny Dahlberg <svartchimpans@gmail.com>,
"Carlos E. R." <robin.listas@telefonica.net>
Cc: dm-crypt mail list <dm-crypt@saout.de>
Subject: [dm-crypt] Re: Aligning entire LUKS/LVM/Ext4 filesystem stack to 4K sectors
Date: Thu, 25 Mar 2021 18:01:16 +1000 [thread overview]
Message-ID: <5621b9d7e6e577a6388695cfa27d20fc3a2c8271.camel@erwinvanlonden.net> (raw)
In-Reply-To: <CA+3G=9jwG465ALjufeuK5ihSQxe5-iOCE5ZhkXh11s+_rqnB6w@mail.gmail.com>
I think the quickest way to find out is:
"lsblk -o name,phy-sec,log-sec"
Output like this shows it nicely:
[ monster % ~ ] lsblk -o name,phy-sec,log-sec
[ 5:57PM ]
NAME PHY-SEC LOG-SEC
sda 512 512
├─sda1 512 512
└─sda2 512 512
├─vg_monster-lv_home 512 512
├─vg_monster-lv_swap 512 512
└─vg_monster-lv_root 512 512
sdb 512 512
├─sdb1 512 512
└─sdb2 512 512
Obviously playing around with the output parameters gives you plenty
flexibility.
Cheers
Erwin
On Wed, 2021-03-24 at 20:53 +0100, Johnny Dahlberg wrote:
>
>
> On Fri, 19 Mar 2021 at 23:21, Carlos E. R.
> <robin.listas@telefonica.net> wrote:
> > On 19/03/2021 22.39, Johnny Dahlberg wrote:
> > > On 19/03/2021, Carlos E. R. <robin.listas@telefonica.net> wrote:
> > > > On 19/03/2021 21.24, Johnny Dahlberg wrote:
> > > > > On 19/03/2021, Maksim Fomin <> wrote:
> > > > > > > On Friday, 19 March 2021 г., 19:09, Johnny Dahlberg <>
> > > > > > > wrote:
> > > >
> > > > ...
> >
> >
> > > > Related question:
> > > >
> > > > How can one, on an exiting encrypted partition, find out what
> > > > size is
> > > > using each layer, and if they are aligned or not?
> > > >
> > > > I am using encrypted partitions on SSD and I'm a bit worried.
> > > >
> > > >
> > >
> > > Hello Carlos!
> > >
> > > First you would check the physical sector size of your SSD. It is
> > > most
> > > likely 4096 bytes (4K). You can check this by doing:
> > >
> > > cat /sys/block/(the parent device such as
> > > nvme0n1)/queue/physical_block_size
> >
> > On the two machines I have running now, both have an nvme system
> > disk,
> > but only one has the encrypted partition on it; both use 512:
> >
> > cer@Telcontar:~> cat /sys/block/nvme0n1/queue/physical_block_size
> > 512
> > cer@Telcontar:~>
> >
> > Isengard:~ # cat /sys/block/sda/queue/physical_block_size
> > 512
> > Isengard:~ #
> >
> > Hum!
> >
>
>
> Since January 2011, all manufacturers began using Advanced Format
> (4096 bytes): https://en.m.wikipedia.org/wiki/Advanced_Format#History
>
> From what I can find online, your Samsung 970 Evo Plus uses 8K
> sectors physically.
>
> >
> > I think I'm good - no worries :-)
> >
> > Thanks! :-)
> >
> > _______________________________________________
> > dm-crypt mailing list -- dm-crypt@saout.de
> > To unsubscribe send an email to dm-crypt-leave@saout.de
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prev parent reply other threads:[~2021-03-25 8:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 16:09 [dm-crypt] Aligning entire LUKS/LVM/Ext4 filesystem stack to 4K sectors Johnny Dahlberg
[not found] ` <_X7kzj_AZLSVcCkPM4xu_QoNVntVev87vOgJfHun_dR43IVunAzxvUFJubPVV3sDAMoJlJJAlFuljdv5Svkz49B5VMFXABWrEEk641NrHs4=@fomin.one>
[not found] ` <ORDtENr6aBENCEKNaBoLivcFJL2TWrcPLZcM1NDn9mSyDJlbXgdwUR5HbCRsw9etKJIKiByQV4qkuFO1h9pVyX4_wv89xQUFNc2CcU8mqug=@fomin.one>
2021-03-19 20:24 ` [dm-crypt] " Johnny Dahlberg
2021-03-19 20:45 ` Carlos E. R.
2021-03-19 21:39 ` Johnny Dahlberg
2021-03-19 22:19 ` Carlos E. R.
2021-03-24 19:53 ` Johnny Dahlberg
2021-03-25 8:01 ` Erwin van Londen [this message]
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