Bug 1740774 - Pad memory volumes to 4096 bytes to support 4K storage
Summary: Pad memory volumes to 4096 bytes to support 4K storage
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: vdsm
Classification: oVirt
Component: Core
Version: 4.30.0
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ovirt-4.3.6
: 4.30.29
Assignee: Pavel Bar
QA Contact: Evelina Shames
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2019-08-13 15:31 UTC by Pavel Bar
Modified: 2019-09-26 19:43 UTC (History)
6 users (show)

Fixed In Version: vdsm-4.30.29
Clone Of:
Environment:
Last Closed: 2019-09-26 19:43:10 UTC
oVirt Team: Storage
Embargoed:
sbonazzo: ovirt-4.3?
pelauter: planning_ack+
frolland: devel_ack+
aefrat: testing_ack+

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
oVirt gerrit 102607 0 'None' 'MERGED' 'storage: Fixed "padToBlockSize()" to correctly pad to 4K' 2019-11-19 05:55:30 UTC
oVirt gerrit 102627 0 'None' 'MERGED' 'storage: Fixed "padToBlockSize()" to correctly pad to 4K' 2019-11-19 05:55:30 UTC

Description Pavel Bar 2019-08-13 15:31:41 UTC 
Pad memory volumes to 4096 bytes to support 4K storage.
This was fixed only partly in 4.3.
Comment 1 Nir Soffer 2019-08-13 19:03:08 UTC 
Raising priority and severity since this can cause failures when cloning
vms with memory volumes.
Comment 2 Nir Soffer 2019-08-13 19:04:14 UTC 
Fred, anything missing in this bug for including in 4.3.6?
Comment 3 Fred Rolland 2019-08-14 10:35:06 UTC 
I see you already targeted it.

The description of the bug is very vague.
Missing: what is the scenario/flow, what is the failure, user impact, reproducible, which storage (only 4k?)

QE should be able to verify this.
Comment 4 Nir Soffer 2019-08-14 17:14:52 UTC 
Without this change, qemu may segfault when copying memory volumes
(e.g bug 1649788).

This issue may have been fixed in qemu, but in vdsm we should not
create images which are not aligned.

In the past we aligned images to 512 bytes, but when using storage
with sector size of 4096 bytes, images should be aligned to 4096 bytes.

This affects only NFS storage since other types of file storage uses
fileutils.padToBlockSize() which is already fixed in 4.3.6 (or before).

I don't know if it is possible to reproduce this qemu segfault, it
depends on qemu version and the contents of the memory volume.

To verify the fix, you can check the size of a memory volume created
when taking a snapshot with memory. The size must be a multiple of 4096.
Comment 5 Avihai 2019-08-25 06:19:13 UTC 
Hi Pavel,

Please provide a clear reproduction/verification scenario so we can QA_ACK this bug.
Comment 6 Avihai 2019-08-25 14:37:33 UTC 
verification scenario is:

1) Create a snapshot with memory thus creating a memory volume 
2) Check the memory volume size(in Bytes) is a multiple of 4096.
Comment 7 Evelina Shames 2019-09-02 05:32:27 UTC 
Verified on:
vdsm-4.30.29-1.el7ev.x86_64
ovirt-engine-4.3.6.4-0.1.el7.noarch
Comment 8 Sandro Bonazzola 2019-09-26 19:43:10 UTC 
This bugzilla is included in oVirt 4.3.6 release, published on September 26th 2019.

Since the problem described in this bug report should be
resolved in oVirt 4.3.6 release, it has been closed with a resolution of CURRENT RELEASE.

If the solution does not work for you, please open a new bug report.
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