Bug 1511034

Summary:	vdoformat program erroneously prints "Exceeds maximum number of slabs" for case where index size is too big
Product:	Red Hat Enterprise Linux 7	Reporter:	Bryan Gurney <bgurney>
Component:	vdo	Assignee:	Sweet Tea Dorminy <sweettea>
Status:	CLOSED ERRATA	QA Contact:	Jakub Krysl <jkrysl>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.5	CC:	awalsh, jkrysl, limershe
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
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Fixed In Version:	6.1.0.57	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-04-10 15:47:46 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Embargoed:

Description Bryan Gurney 2017-11-08 15:09:43 UTC

Description of problem:
If the user creates a VDO volume with --indexMem=10, it will create a VDO volume with a UDS index in dense mode that uses 10 GB of memory, and attempts to reserve 100 GB of storage space on the configured device.  This would call the 

Version-Release number of selected component (if applicable):
vdo-6.1.0.34-8

How reproducible:
100%

Steps to Reproduce:
1. Install the kmod-kvdo and vdo packages.
2. Add a storage device that has less than the required amount of disk space for a UDS index.
3. Execute "vdo create --name=vdo1 --device=<device> --indexMem=10 --verbose (or use an "--indexMem=" value corresponding to about 1 GB of memory per 10 GB of storage space, in a way that yields insufficient storage space to contain the index).

Actual results:
vdo: ERROR - vdoformat: formatVDO failed on '/dev/sdc': VDO Status: Exceeds maximum number of slabs supported

Expected results:
vdoformat prints a message indicating that there is not enough space to create the UDS index.

Additional info:

Comment 2 Bryan Gurney 2017-11-10 20:03:35 UTC

In a case where the device has enough space to create the index, but does not have enough space to create a full slab (default size 2 GB), this error will appear:

vdo: ERROR - vdoformat: formatVDO failed on '/dev/TEST/backing': VDO Status: Out of space

The test logical volume above was 4 GB in size; it was enough to contain the 2.5 GB UDS index, but not enough to contain a single 2 GB slab.

Comment 3 Bryan Gurney 2017-11-10 20:32:18 UTC

*** Bug 1505748 has been marked as a duplicate of this bug. ***

Comment 5 Jakub Krysl 2017-11-21 13:08:11 UTC

vdo-6.1.0.55-10 with 5.5T disk:

# vdo create --name vdo2 --device /dev/sdg --indexMem 1000 --verbose
Creating VDO vdo2
    modprobe kvdo
    vdoformat --uds-checkpoint-frequency=0 --uds-memory-size=1000 /dev/sdg
vdo: ERROR - vdoformat: formatVDO failed on '/dev/sdg': VDO Status: Out of space

THe new indication does not specifically says there is not enough space for the index, but it clearly says it is a space issue, which is good enough.

Comment 8 errata-xmlrpc 2018-04-10 15:47:46 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

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

https://access.redhat.com/errata/RHEA-2018:0871