db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Kim Haase (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DERBY-5691) Document that Write Caching must be disabled to avoid possible database corruption
Date Thu, 19 Apr 2012 15:08:40 GMT

    [ https://issues.apache.org/jira/browse/DERBY-5691?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13257531#comment-13257531

Kim Haase commented on DERBY-5691:

It sounds as if we need a topic called something like "Avoiding database corruption". Maybe
it belongs at the beginning of part 2 of the Admin Guide, just before "Checking database consistency",
a related topic. We can then add to it as need be. Any other thoughts?

This topic would include the problem with Windows write caching as well as the other two mentioned
by Kathey.

I thought the caching problem could be a Tuning Derby topic, since caching helps performance,
but it turns out that it is often enabled by default on Windows systems. It is enabled on
my ancient Windows XP system, for instance. People may well not know they are using it.

I am guessing that "using runtime compression" means calling the SYSCS_UTIL.SYSCS_COMPRESS_TABLE
or SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE procedure -- let me know if I'm off track here.

> Document that  Write Caching  must be disabled to avoid possible database corruption
> ------------------------------------------------------------------------------------
>                 Key: DERBY-5691
>                 URL: https://issues.apache.org/jira/browse/DERBY-5691
>             Project: Derby
>          Issue Type: Improvement
>          Components: Documentation
>         Environment: Microsoft Windows
>            Reporter: Stan Bradbury
>            Assignee: Kim Haase
>              Labels: Write_caching
> Suggestion that we document a recommendation that Windows Write Caching be disabled on
machines using Derby.
> The following article warns about Write Caching on Windows as a possbile source of database
>      http://support.microsoft.com/kb/281672
> It is possible that this could be the cause of some unexplained Derby corruptions identified
after power failure of other system interupt.
> Links explaining how to disable Write Caching:
>   Win 2K: http://support.microsoft.com/kb/259716
>    Win 2008: http://support.microsoft.com/kb/324805
> From the Windows 2008 article:
> With some third-party programs, disk write caching has to be turned on or off. Additionally,
turning disk write caching on may increase operating system performance; however, it may also
result in the loss of information if a power failure, equipment failure, or software failure
occurs. This article describes how to turn disk write caching on or off.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira


View raw message