Solving disk offline issue in Windows

You may experienced a message "The disk is offline because it has a signature collision with another disk that is online" / "磁碟簽章發生衝突" in Windows. The case for myself is switching two RAID-1 drives back to non-RAID devices, where the two drives will become identical and cause the collision problem. The following is the solution to turn on the offline disk:

c:\>diskpart
c:\>list disk (you may see your offline disk is in the list)
c:\>select disk 1
c:\>offline disk
c:\>online disk


Reference: http://beddingmall.blogspot.com/2011/01/blog-post_04.html

Delete Acronis Failed Task

Just tried their solution, it works:

1. Run Schedmgr.exe and issue the following command: task zap
2. Delete the content of the following folders:
   Windows XP, Windows 2000/2003 (32/64 bit)
   - \Documents and Settings\All Users\Application Data\Acronis\BackupAndRecovery\MMS\Policies\
   - \Documents and Settings\All Users\Application Data\Acronis\BackupAndRecovery\MMS\TasksStorage\
   - \Documents and Settings\All Users\Application Data\Acronis\BackupAndRecovery\MMS\PolicyStatistics
   Windows Vista, Windows 7, Windows Server 2008 (32/64 bit)
   - \ProgramData\Acronis\BackupAndRecovery\MMS\Policies\
   - \ProgramData\Acronis\BackupAndRecovery\MMS\TasksStorage\
   - \ProgramData\Acronis\BackupAndRecovery\MMS\PolicyStatistics
3. Recreate the tasks

Ref: http://forum.acronis.com/forum/10652

Column aggregation in Oracle

Suppose we have a table (TBL) in Oracle with columns (CATEGORY, ATTR). Consider the following:

CATEGORY	ATTR
1	A
1	B
1	C
2	D
2	E
2	F
3	X
3	Y
3	Z

We want to convert the table as follows:

CATEGORY	ATTR
1	A,B,C
2	D,E,F
3	X,Y,Z

This can be done via the SQL below:

select CATEGORY, 
       xmlagg(xmlelement(c, ATTR || ',')).extract('//text()') 
from TBL 
group by CATEGORY

Determine user in Tomcat

To determine user authentication info in Tomcat, we can use the following:

getRemoteUser()
isUserInRole(String role)

Both methods are under javax.servlet.http.HttpServletRequest.

Using ArcGIS JS API v2.5 - v2.8

Some notes on using their API:

• In 2.5, the path is /library/2.5/arcgis (or arcgis_compact)
• In 2.6, the path changed to /library/2.6/jsapi (or jsapicompact), but the manual doesn't changed. So be careful when following the installation manual
• The file in /library/2.6/jsapi/js/esri/jsapi.js will create a Javascript error. You might need to replace the file content with the one in ESRI ArcGIS JS API production site.

Something more about the Javascript files in the API:

• The jsapi.js contains UTF8 characters (‰ - u8240, ¤ - u0164), when ArcGIS JS API "index.jsp" includes this file using <jsp:include>, the UTF8 characters will corrupted. I found two solutions for that
1. Modify the jsapi.js, swap those UTF8 characters back to escaped (\u) characters, and save the file back as ANSI format. OR
2. Modify the "index.jsp", avoid using <jsp:include>, try to use file reader with encoding specified. For example: FileUtils.readFileToString(new File(filepath_), "UTF8"); (where FileUtils is from org.apache.commons.io package)

100% Height DIV

The trick is to set body with height:100% in CSS:

<style>
   html, body {
      margin: 0px;
      height: 100%;
   }
</style>

Then DIV's CSS height:100% will work !

Cynefin methods

Cynefin methods, tools, and techniques have been successfully applied in organisations to address areas such as corporate strategy, innovation, culture transformation, weak signal detection, social networking, mergers & acquisitions, knowledge management and ageing workforce. It is useful in capturing tacit knowledge.
Ref: Cynefin framework (http://www.cynefin.net)

Themes for Notepad2

There is a nice color theme called obsidian for Notepad2. But it will hide your cursor after  importing it. To fix this, give a color and size to the caret in notepad2.ini. For example:

[Default Text]
...
Caret (Color, size 1-3)=fore:#FFFFFF; size:2;
...


Link to Obsidan for Notepad2

Some options for Tomcat 6

Not much options found, but I drop down the useful ones for reference. Note that those options should be assigned to the CATALINA_OPTS. Actually, you may put them in catalina.bat.

• Startup memory size
  -Xms256m

• Maximum memory size
  -Xmx256m

• Garbage collection path
  -Xloggc:/gc.log

• Disable DNS caching
  -Dsun.net.inetaddr.ttl=0

• Skip quote escape checking (If you have tag like this <mytags:tag value="<%= "hi!" %>" /> , which is validate in Tomcat 5 before. In Tomcat 6, you may need to turn on the following option to prevent running into error. Ref: http://www.andowson.com/posts/list/346.page)
  -Dorg.apache.jasper.compiler.Parser.STRICT_QUOTE_ESCAPE=false

• Turn on JMX remote
  -Dcom.sun.management.jmxremote
  -Dcom.sun.management.jmxremote.port=9004
  -Dcom.sun.management.jmxremote.authenticate=false
  -Dcom.sun.management.jmxremote.ssl=false

• Set default Tomcat language / locale to English
  -Duser.language=en

To measure a string length in pixel using Javascript

One may make use of Span.offsetWidth to measure the length of a string in Javascript environment, consider the following example:


<html>
<body>
    <select id="select1" style="width:100px;" onchange="checkStringWidth()">
        <option value="1">abcde abcde abcde abcde abcde</option>
        <option value="2">abcde abcde abcde abcde</option>
    </select>
    <br>
    Selected option: <span id="span1"></span>
    <br>
    Text width: <span id="lbWidth"></span>
</body>
</html>


<script>
    function checkStringWidth() {
        var select1 = document.getElementById('select1');
        var span1   = document.getElementById('span1');
        var lbWidth = document.getElementById('lbWidth');
        span1.innerHTML = select1.options[select1.selectedIndex].text;        
        lbWidth.innerHTML = span1.offsetWidth;
    }
</script>