From: Demi Marie Obenour <demi@invisiblethingslab.com>
To: Joe Thornber <thornber@redhat.com>
Cc: "development, device-mapper" <dm-devel@redhat.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>,
"Qubes OS Development Mailing List"
<qubes-devel@googlegroups.com>,
dm-devel@lists.ewheeler.net
Subject: Thin pool CoW latency
Date: Sun, 5 Mar 2023 15:40:02 -0500 [thread overview]
Message-ID: <ZAT+IoCfuZtRnnhm@itl-email> (raw)
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
Like Eric, I am very concerned about CoW latency and throughput. I
am almost certain that allocating new blocks and snapshot copy-on-write
are _the_ hot paths in Qubes OS. In particular, I suspect that
workloads such as building an image in a throwaway VM or installing
packages onto a root volume that had just been shapshotted are dominated
by metadata operations, rather than by in-place updates. I suspect that
frequently-snapshotted volumes will observe similar behavior in general.
- --
Sincerely,
Demi Marie Obenour (she/her/hers)
Invisible Things Lab
-----BEGIN PGP SIGNATURE-----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=/KY9
-----END PGP SIGNATURE-----
reply other threads:[~2023-03-05 20:42 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=ZAT+IoCfuZtRnnhm@itl-email \
--to=demi@invisiblethingslab.com \
--cc=CAJ0trDYAyHHh2crMAQuQPMt3FzFmii0nmLnsL5N-cdhfvWZnMg@mail.gmail.com \
--cc=dm-devel@lists.ewheeler.net \
--cc=dm-devel@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=marmarek@invisiblethingslab.com \
--cc=qubes-devel@googlegroups.com \
--cc=thornber@redhat.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
all inboxes | Powered by JetHome®