Bug 849953
| Summary: | qcow2 + read|reread block performance degrade on 6.3 guest compared to 5.9 guest on 5.9 host | ||||||
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| Product: | Red Hat Enterprise Linux 6 | Reporter: | Xiaomei Gao <xigao> | ||||
| Component: | kernel | Assignee: | Asias He <asias> | ||||
| Status: | CLOSED NOTABUG | QA Contact: | Red Hat Kernel QE team <kernel-qe> | ||||
| Severity: | medium | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 6.3 | CC: | areis, asias, juzhang, michen, mst, rhod, wquan | ||||
| Target Milestone: | rc | ||||||
| Target Release: | --- | ||||||
| Hardware: | x86_64 | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2012-09-24 01:39:02 UTC | Type: | Bug | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Attachments: |
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Created attachment 612088 [details]
iozone script
*** Bug 849944 has been marked as a duplicate of this bug. *** There are three sets of tests that Xiaomei run: 1) with direct io 2) with small file < 0.9 system ram size 3) with large file > 2.0 system ram size The 'regression' we can is only in test 2). In this case, we are testing the I/O in ram instead of the real disk I/O. The result is not reliable nor stable. E.g the read speed in test 2) is 4883 MB/s while the read speed in test 1) is 101 MB/s. This is not a regression, I am closing it. |
hi, asias please check the attachment. Best Regards xigao