On Exchange Server 2007 you may encounter a quota violation error when attempting to move the storage group logs path for one of your storage groups.

Summary: 1 item(s). 0 succeeded, 1 failed.
Elapsed time: 01:35:36

SG Public Folders
Failed

Error:
WMI exception occured on server ‘exchangeserver.domain.local’: Quota violation

Quota violation

Exchange Management Shell command attempted:
move-StorageGroupPath -Identity ‘EXCHANGESERVER\SG Public Folders’ -LogFolderPath ‘T:\Path’

Elapsed Time: 01:35:36

This error can occur when there are a very large number of transaction log files in the current log path.  To resolve the issue you can:

1. Run a backup of the database in the storage group to truncate the logs.
2. Manually copy (eg xcopy or Robocopy) the log files to the new location and edit the storage group log path using ADSIEdit.msc.

In a situation where the log volume is full and the database in question is dismounted the backup option is not available to you.  Instead you could extend the logging volume by adding more capacity to it, or turn on circular logging temporarily so that the database will mount and truncate all of the existing log files.