Bug 1899663

Summary:	[pvc-migrate] Source pvc's of specific size and usage can result in erroneously large PVCs dynamically provisioned on target (1Pi range)
Product:	Migration Toolkit for Containers	Reporter:	Erik Nelson <ernelson>
Component:	General	Assignee:	Pranav Gaikwad <pgaikwad>
Status:	CLOSED UPSTREAM	QA Contact:	Xin jiang <xjiang>
Severity:	unspecified	Docs Contact:	Avital Pinnick <apinnick>
Priority:	unspecified
Version:	1.3.z	CC:	ernelson
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Last Closed:	2021-04-07 20:38:18 UTC	Type:	Bug
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Description Erik Nelson 2020-11-19 18:17:31 UTC

Description of problem:

This is a pvc-migrate bug and not a problem with mtc-proper: https://github.com/konveyor/pvc-migrate/issues/147

It's been observed that source pvcs of specific sizes/usage can result in pvs of  size Pi (petabyte) being delivered. When pvc-migrate recognizes that the usage of a pvc on the source could breach the requested size (in the case where the volume has been resized outside of k8s), it will bias the requested pv on the target to account. This is known as the volume adjustment. In the observed case, volumes of >1Ti were in use, so this number was adjusted when requested on the target to something on the order of 1-2k Gi. This resulted in the AWS EBS dynamic provisioner delivering a PV of 1 Pi.

It's difficult for us to tell without the specific adjustment file that outlines the details (which we do not currently have), so this requires some investigation.

Version-Release number of selected component (if applicable):
pvc-migrate 1.1.4

How reproducible:
Should be everytime, although we do not have an example adjustment file that demonstrates the specific problem values.

Actual results:
1 Pi volume is provisioned and delivered target side

Expected results:
Something of a more reasonable size

Comment 1 Erik Nelson 2021-04-07 20:38:45 UTC

This has been fixed upstream, and pvc-migrate is largely obsolete with the advent of DVM in MTC.