Bug 1523216 – fuse xlator uses block size and fragment size 128KB leading to rounding off in df output

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Bug 1523216 - fuse xlator uses block size and fragment size 128KB leading to rounding off in df output

Summary:	fuse xlator uses block size and fragment size 128KB leading to rounding off i...

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Gluster Storage
Classification:	Red Hat
Component:	fuse (Show other bugs)
Sub Component:
Version:	3.4
Hardware:	Unspecified Unspecified

Priority	unspecified Severity unspecified
Target Milestone:	---
Target Release:	RHGS 3.4.0
Assigned To:	Csaba Henk
QA Contact:	Vinayak Papnoi
Docs Contact:

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Depends On:	1523219
Blocks:	1503137
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Reported:	2017-12-07 07:28 EST by Raghavendra Talur
Modified:	2018-10-01 01:59 EDT (History)
CC List:	11 users (show)

See Also:	1511973
Fixed In Version:	glusterfs-3.12.2-8
Doc Type:	If docs needed, set a value
Doc Text:
Story Points:	---
Clone Of:	1511973
Environment:
Last Closed:	2018-09-04 02:40:20 EDT
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
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Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

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External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2018:2607	None	None	None	2018-09-04 02:42 EDT

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Comment 2 Raghavendra Talur 2017-12-07 07:30:50 EST

This difference is because FUSE uses a block size and fragment size of 128K instead of using the backend filesystem's block size.

When statvfs call is made, this is the statvfs buffer content

      blocks  bfree   bavail
gfapi 259584, 248433, 251028
brick 259584, 251028, 251028
fuse    8112,   7763,   7844


As you can see, gfapi and brick match in total blocks and bavail.
There is a difference in bfree because of posix xlator. Posix xlator deducts 1% of the total blocks from free blocks.

The numbers in fuse are the numbers in gfapi row divided by 32(because the numbers obtained from brick are for 4K blocks and fuse wants to communicate in terms of 128K blocks). Here, we are converting into a larger unit and value is rounded off.

df on a mount point would get data from fuse and hence the discrepancy.

Comment 9 errata-xmlrpc 2018-09-04 02:40:20 EDT

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/RHSA-2018:2607

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