What are the recommended settings for defragmentation on Windows for iSCSI LUNs in ONTAP
Applies to
ONTAP 9
Answer
- Defragmentation on iSCSI LUNs in ONTAP is generally not recommended.
- Here are the key reasons and recommendations:
- WAFL (Write Anywhere File Layout):
- NetApp storage systems use WAFL, which manages physical storage fragmentation internally.
- Therefore, defragmentation at the Windows level does not contribute to performance improvement and can increase I/O load, potentially degrading performance.
- I/O Load:
Defragmentation generates a significant amount of I/O, which can increase the load on the storage system and negatively impact performance.
- LUN Resizing:
If a LUN has been resized, standard Windows defragmentation may not be sufficient. Specialized tools or methods may be required to handle defragmentation properly in such cases.
- Avoid Defragmentation:
It is generally advisable to avoid running defragmentation on iSCSI LUNs hosted on ONTAP systems.
- Specialized Tools:
If defragmentation is necessary, consider using specialized tools that can handle defragmentation more effectively, especially if the LUN has been resized.
- LUN Replacement:
- NetApp storage systems use WAFL, which manages physical storage fragmentation internally.
- Therefore, defragmentation at the Windows level does not contribute to performance improvement and can increase I/O load, potentially degrading performance.
