Bug 1032674

Summary: Make default physical block size 4K
Product: Red Hat Enterprise Linux 7 Reporter: Paolo Bonzini <pbonzini>
Component: qemu-kvmAssignee: Kevin Wolf <kwolf>
Status: CLOSED WONTFIX QA Contact: Virtualization Bugs <virt-bugs>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.0CC: areis, hhuang, juzhang, michen, pbonzini, rbalakri, virt-maint, wquan
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
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Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2016-08-01 20:35:38 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 748906    
Bug Blocks:    

Description Paolo Bonzini 2013-11-20 14:58:30 UTC 
For RHEL7.0, making physical block size 4K will make XFS use 4K blocks, and will avoid RMW operations when writing to the journal.

This is not expected to bring benefits for anything other than XFS, since LVM and parted are usually aligning things to 1MB anyway.

This is also the first step towards providing 4K native disks.  However, this requires UEFI support.
Comment 8 Kevin Wolf 2016-06-21 15:32:21 UTC 
Paolo, do we still want this? I don't expect it to make a difference in practice
and apparently nobody was interested enough to bring it up again, but maybe it's
time to just make the change or close the BZ...
Comment 9 Paolo Bonzini 2016-07-15 07:14:48 UTC 
I say close it... We can just do it upstream, there's no need for a BZ.
Comment 10 Kevin Wolf 2016-08-01 20:35:38 UTC 
Ok, makes sense, I'm closing it now.