From: Launchpad Bug Tracker <1884831@bugs.launchpad.net>
To: qemu-devel@nongnu.org
Subject: [Bug 1884831] [NEW] qemu-nbd fails to discard bigger chunks
Date: Tue, 23 Jun 2020 21:16:56 -0000 [thread overview]
Message-ID: <159294701710.25289.6165876669234081304.launchpad@gac.canonical.com> (raw)
In-Reply-To: 159294358125.13789.3860026407311199131.malonedeb@wampee.canonical.com
You have been subscribed to a public bug:
This report is moved from systemd to here:
https://github.com/systemd/systemd/issues/16242
A qemu-nbd device reports that it can discard a lot of bytes:
cat /sys/block/nbd0/queue/discard_max_bytes
2199023255040
And indeed, discard works with small images:
$ qemu-img create -f qcow2 /tmp/image.img 2M
$ sudo qemu-nbd --connect=/dev/nbd0 /tmp/image.img
$ sudo blkdiscard /dev/nbd0
but not for bigger ones (still smaller than discard_max_bytes):
$ qemu-img create -f qcow2 /tmp/image.img 5G
$ sudo qemu-nbd --connect=/dev/nbd0 /tmp/image.img
$ sudo blkdiscard /dev/nbd0
** Affects: qemu
Importance: Undecided
Status: New
--
qemu-nbd fails to discard bigger chunks
https://bugs.launchpad.net/bugs/1884831
You received this bug notification because you are a member of qemu-devel-ml, which is subscribed to QEMU.
next prev parent reply other threads:[~2020-06-23 21:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 20:19 [Bug 1884831] [NEW] qemu-nbd fails to discard bigger chunks TobiasHunger
2020-06-23 20:38 ` Eric Blake
2020-06-23 20:38 ` [Bug 1884831] " Eric Blake
2020-06-23 20:53 ` Eric Blake
2020-06-23 21:16 ` Eric Blake
2020-06-23 21:16 ` Launchpad Bug Tracker [this message]
2020-06-23 21:35 ` Eric Blake
2020-07-22 21:41 ` Eric Blake
2020-07-22 21:41 ` Eric Blake
2021-05-07 2:53 ` Thomas Huth
2021-05-07 12:30 ` Eric Blake
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