From: Thomas Lamprecht <t.lamprecht@proxmox.com>
To: Filip Schauer <f.schauer@proxmox.com>,
Proxmox Backup Server development discussion
<pbs-devel@lists.proxmox.com>
Subject: Re: [pbs-devel] [PATCH backup v2 2/2] disks: wipe: only zero out the first 1 MiB
Date: Wed, 12 Feb 2025 14:44:53 +0100 [thread overview]
Message-ID: <106204c1-a678-47df-85a2-217d6a989a0f@proxmox.com> (raw)
In-Reply-To: <01a0b4f9-c8e2-49b2-ad64-a9cfc42a1e77@proxmox.com>
Am 12.02.25 um 11:24 schrieb Filip Schauer:
> On 11/02/2025 19:42, Thomas Lamprecht wrote:
>> I have some faint remembrance that we had to increase the area we zero
>> out for ceph OSDs and/or for the installer.
>
> You are right. We zero out the first 200 MiB to prevent a problem with
> OSD creation. [0] [1] Although I am unable to reproduce this on Ceph
> Quincy, making sure the disk is properly wiped does not hurt. So we can
> drop this patch.
Thanks for checking, seems like Ceph nowadays writes out labels on quite a
few more places [0] depending on the block dev size; albeit only once in the
range of 0 to 200 MB. I checked and this is relatively new though (commit
from January 2024 [1]) and only included in Squid 19.2.1 FWICT.
[0]: https://github.com/ceph/ceph/blob/main/src/os/bluestore/BlueStore.cc#L138-L146
[1]: https://github.com/ceph/ceph/commit/4b8197b9931e1597b5aa3b02660a9b77ea4aa124
FWIW, I'm not completely opposed in doing less writes, if the block device
is backed by some thin provisioned storage it might be also thankful if it
has less data to explicitly track (albeit zeros are often special cased
and as such relatively cheap most of the time).
If we ever reuse this code for PVE it would need to become opt-in though
so that we can enable it for the cases like wiping in preparation of
creating a Ceph OSD.
But I saw you send a v3 already with this left out, which is IMO fine too
for now.
_______________________________________________
pbs-devel mailing list
pbs-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel
prev parent reply other threads:[~2025-02-12 13:44 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-11 16:26 [pbs-devel] [PATCH backup v2 0/2] fix #5946: disks: wipe: ensure GPT header backup is wiped Filip Schauer
2025-02-11 16:26 ` [pbs-devel] [PATCH backup v2 1/2] " Filip Schauer
2025-02-11 18:39 ` Thomas Lamprecht
2025-02-12 11:01 ` Filip Schauer
2025-02-11 16:26 ` [pbs-devel] [PATCH backup v2 2/2] disks: wipe: only zero out the first 1 MiB Filip Schauer
2025-02-11 18:42 ` Thomas Lamprecht
2025-02-12 10:24 ` Filip Schauer
2025-02-12 13:44 ` Thomas Lamprecht [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=106204c1-a678-47df-85a2-217d6a989a0f@proxmox.com \
--to=t.lamprecht@proxmox.com \
--cc=f.schauer@proxmox.com \
--cc=pbs-devel@lists.proxmox.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Service provided by Proxmox Server Solutions GmbH | Privacy | Legal