MySQL 4 to MySQL 5 Character Sets and Collation

Moving from MySQL 4 to MySQL 5 caused a few issues on Joomla websites. The problems stem from MySQL 4 using latin1 swedish as default but some applications like Joomla want utf8 so:

1. Re-export the database (it is Ok to do this from the existing MySQL 5 database):

mysqldump -u username -p –default-character-set=latin1 –compatible=mysql40 dbname > dump.sql

2. Import the database again (overwriting the current oddly encoded tables – you do have a backup right!) :

mysql -u username -p –default-character-set=utf8 dbname < dump.sql

Note: It is not enough to just convert the database / tables with:

ALTER DATABASE db_name DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE tbl_name CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;

Although this will convert the database defaults it does not perform the conversion from latin1 to utf8 on the existing actual content.

How to Align Exchange I/O with Storage Track Boundaries

Apparently disk performance is much improved if you do this. Make sure you do this for each new physical disk. Procede as follows –

  1. If the disk you are aligning is already blank (raw), proceed to Step 3. If the disk contains data, back up the disk before proceeding.
  2. Delete all partitions on the disk.
  3. Open a Command Prompt window, and run Diskpart.exe.
  4. At the Diskpart command prompt, type List Disk and press ENTER. If the disk you want to align does not appear in the list, make sure that it exists and is accessible using the Disk Management snap-in.
  5. At the Diskpart command prompt, type Select Disk X, where X is the number of the disk as shown in the output of the List Disk command. Diskpart should return a message that indicates that Disk X is the selected disk.
  6. At the Diskpart command prompt, type Create Partition Primary Align=X, where X is the value recommended by your storage vendor. If your storage vendor does not have any specific recommendations, we recommend that you use 64.
  7. At the Diskpart command prompt, type Assign Letter=<DriveLetter>.
  8. After the drive letter is assigned, type exit to exit the Diskpart tool.
  9. Use the Disk Management snap-in or the Format command to format the partition as an NTFS-formatted partition.

The link to the MS technet article is –

http://technet.microsoft.com/en-us/library/aa998219.aspx

Physical disk resource does not successfully move to another cluster node

We experienced a problem when trying to move a physical disk resource from one cluster node to another where the move operation is unsuccessful. This turned out to be because some of the hard disk signatures were missing from the Windows registry. The solution to this is described in the following KB article –

http://support.microsoft.com/kb/932465

The hotfix described has been applied to all the Exchange virtual server nodes. This alone did not fix the problem and we had to edit the registry as described in method 2.

Moving virtual servers to a different cluster node

This should always be done from an Exchange management shell using the following command –

Move-ClusteredMailboxServer -id virtual server ID -MoveComment “Move virt-x to target node” -target target node

The command will run checks on the virtual server before attempting to move nodes.  This phase may take up to 3 or 4 minutes. Use the cluster administrator to monitor the node move – this usually takes around 50 seconds to complete if all goes well!