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Who When What Removed Added
Amit Shah 2011-02-11 05:29:08 UTC CC amit.shah
Assignee virt-maint kwolf
Shirley Zhou 2011-02-12 07:59:19 UTC Priority unspecified medium
Severity unspecified medium
Nicole Dai 2011-02-12 10:14:48 UTC CC ndai
Min Deng 2011-03-30 02:53:20 UTC CC mdeng
juzhang 2011-09-03 08:38:53 UTC CC juzhang
Kevin Wolf 2011-12-07 16:21:47 UTC CC wdai
Ademar Reis 2012-06-22 15:18:00 UTC CC areis
Miroslav Rezanina 2013-02-25 06:54:52 UTC CC mrezanin
Ademar Reis 2013-02-27 13:52:40 UTC Status NEW CLOSED
Resolution --- WONTFIX
Doc Text NOTE: this is a corner case which doesn't make sense in practice and should not be hit in the field unless the user makes a mistake.

Cause: Qemu may hit timeouts when working with very large images (>= 2TiB) created with very small cluster sizes (512bytes). The default cluster size is 64KiB and we see no reason to use such small cluster size in such cases, as it hits performance in order to save a few bytes.

Consequence: block I/O errors due to timeouts

Workaround (if any): use standard cluster size or bigger (default of 64k works fine).

Result: no block I/O error.
Doc Type Bug Fix Known Issue
Last Closed 2013-02-27 08:52:40 UTC
Eliska Slobodova 2013-09-20 15:18:44 UTC Doc Text NOTE: this is a corner case which doesn't make sense in practice and should not be hit in the field, unless the user makes a mistake.

Cause: Qemu may hit timeouts when working with very large images (>= 2TiB) created with very small cluster sizes (512bytes). The default cluster size is 64KiB and we see no reason to use such small cluster size in such cases, as it hits performance in order to save a few bytes.

Consequence: block I/O errors due to timeouts

Workaround (if any): use standard cluster size or bigger (default of 64k works fine).

Result: no block I/O error.
When working with very large images (larger than 2TB) created with very small cluster sizes (for example, 512bytes), block I/O errors can occur due to timeouts in qemu. To prevent this problem from occurring, use the default cluster size of 64KiB or larger.
John Skeoch 2015-03-05 00:52:38 UTC CC mshao

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