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Bug 177620 - kernel device-mapper snapshot: barriers are not supported
kernel device-mapper snapshot: barriers are not supported
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: kernel (Show other bugs)
All Linux
medium Severity medium
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Assigned To: Alasdair Kergon
Brian Brock
Depends On:
Blocks: 168430
  Show dependency treegraph
Reported: 2006-01-12 08:33 EST by Alasdair Kergon
Modified: 2007-11-30 17:07 EST (History)
3 users (show)

See Also:
Fixed In Version: RHSA-2006-0132
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2006-03-07 16:13:43 EST
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RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
dm-snapshot-barriers-not-supported (732 bytes, patch)
2006-01-12 08:33 EST, Alasdair Kergon
no flags Details | Diff

  None (edit)
Description Alasdair Kergon 2006-01-12 08:33:45 EST
Created attachment 123111 [details]
Comment 1 Alasdair Kergon 2006-01-12 08:33:45 EST
The snapshot target does not handle I/O barriers correctly so it should refuse
to process them.  Otherwise code that relies on them working could lead to data
Comment 2 Alasdair Kergon 2006-01-12 08:56:36 EST
The mapping functions always pass reads through to the underlying devices
immediately, but writes may get delayed.
Comment 8 Red Hat Bugzilla 2006-03-07 16:13:44 EST
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

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