In eDiscovery Analyzer, as the disks in use become full and near their capacity, the indexes can become corrupt as a result of incomplete data being written to an index. A collection with a corrupt index cannot be used and must be deleted and re-indexed.
Resolving the problem
The config.xml file can be used to configure how often free disk space is checked, the free disk space threshold below which low disk space warnings will be generated, and the minimum amount of free disk space required for eDiscovery Analyzer to run.
If you are running any version of eDiscovery Analyzer 2.2, it is recommended that you edit the config.xml file to increase the default values. Installing an eDiscovery Analyzer Fix Pack does not automatically update the config.xml file; you must manually update the file to change any of the values.
In the config.xml file, the checkIntervalForLowWaterMarkInSec setting configures the amount of time (in seconds) between periodic free disk space checks.
The lowWaterMarkInMB setting configures the free disk space threshold for low disk space warnings. These warnings are logged each time free disk space is checked and the free disk space is below the specified threshold, until the system goes into safe mode (see below.) The recommended range for this setting is 1000 MB - 5000 MB, depending on free disk capacity, the size of the collections you intend to index, and how fast the collection data is written to the disk.
The minDiskSpaceRequiredToRunInMB setting configures the minimum amount of free disk space required to run eDiscovery Analyzer. If the amount of free disk space is checked and it is less than the specified value, eDiscovery Analyzer will save its collection state, avoiding possible index corruption, and go into safe mode. The recommended range for this setting is 500 MB - 2500 MB. When in safe mode, you will receive the following error when trying to log into eDiscovery Analyzer:
"A severe system or disk error occurred. Format and review the system log for details."
Depending on your system configuration, there can be more than one disk having data written to it. In such cases, eDiscovery Analyzer reports the disk on which the error occurred, as well as the disk status, to < EDA_HOME>/log/stderr.txt. This enables you to determine why eDiscovery Analyzer went into safe mode.
To re-enable the system, shut down eDiscovery Analyzer, free up a suitable amount of disk space, then restart eDiscovery Analyzer.
The following is an example of the free space size thresholds and time interval in the config.xml file:
<lowWaterMarkInMB> 2000 </lowWaterMarkInMB>
<minDiskSpaceRequiredToRunInMB> 1000 </minDiskSpaceRequiredToRunInMB>
The config.xml file can be found in <EDA_HOME>/config. To make changes to this file, shut down eDiscovery Analyzer, edit the file, then restart eDiscovery Analyzer.
Note: In infrequent cases, such as where the interval time to check the disk space is set too high, hard disk space capacity can still be reached without the warning logs being generated. There is a possibility in this case that index is corrupt.