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From: Sergey Matveev <stargrave@stargrave•org>
To: nncp-devel@lists.cypherpunks.su
Subject: Re: What is /hdr/ subdirectory?
Date: Wed, 11 Mar 2026 10:36:20 +0300 [thread overview]
Message-ID: <abEbdXlyqlGNZFK5@stargrave.org> (raw)
In-Reply-To: <9adc2cdb-2aea-4d30-b933-0b77c62d6988@danisch.de>
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Greetings!
*** Hadmut Danisch [2026-03-11 00:28]:
>and I'm hunting the problem, why they do have different ownerships, the hdr
>file is owned by root and silently skipped by the daemon.
Maybe different toss/daemon processes running at different times with
different permissions/owners.
>So my question is: What is the /hdr/ file? On what occasion is it generated?
It is just a "cached" version of encrypted packet's header. Just its
stripped part. There are options to disable its generation entirely.
That feature was created to speed up process of listing/searching in big
spools on ZFS. ZFS uses by default rather big records: 128KiB. So
reading even a single byte of the packet, will lead to at least reading
of the single block, which is up to 128KiB (before compression). That
leads to big read-amplification during searching for packets in the
spool with acceptable niceness. Those hdr files is just a hack to
prevent that read-amplification.
--
Sergey Matveev (http://www.stargrave.org/)
LibrePGP: 12AD 3268 9C66 0D42 6967 FD75 CB82 0563 2107 AD8A
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prev parent reply other threads:[~2026-03-11 7:36 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-10 23:28 What is /hdr/ subdirectory? Hadmut Danisch
2026-03-11 2:50 ` John Goerzen
2026-03-11 11:51 ` Permissions (Was: What is /hdr/ subdirectory?) Hadmut Danisch
2026-03-11 12:08 ` Permissions John Goerzen
2026-03-11 12:32 ` Permissions Hadmut Danisch
2026-03-11 16:27 ` Permissions John Goerzen
2026-03-11 16:35 ` Permissions Hadmut Danisch
2026-03-11 16:48 ` Permissions John Goerzen
2026-03-11 16:30 ` Permissions John Goerzen
2026-03-15 8:17 ` Permissions Sergey Matveev
2026-03-11 7:36 ` Sergey Matveev [this message]