How to increase the maximum number of files for a flexible volume

Applies to

• ONTAP 9
• Flexible Volume (FlexVol)
• Maximum inode or file count

Description

This article describes how to increase the maximum number of files (inodes) for a Flexible volume.

When a volume is out of inodes, ONTAP will alert you with one or more of the following error messages:

• Error message: file system is out of inodes
• wafl.vol.outOfInodes: file system on Volume vol_test1@vserver:vserver_1 is out of inodes because it has reached the maximum number of files
• wafl.vol.runningOutOfInodes: The file system on Volume vol1@vserver:20884ed5-68e5-11ea-a757-00a098c4fca2 is using 80 percent or more of the files that can be contained on the volume.
• INODE: System/Cluster Notification from filer (OUT OF INODES) ALERT

Procedure

Note: We suggest reviewing the following before making changes: Considerations before increasing the file count in ONTAP

1. Review current settings with the volume show command in advanced privilege mode:

::> set advanced

::*> volume show -vserver svm1 -volume vol1 -fields size,files,files-used,files-maximum-possible   

vserver volume size  files    files-used files-maximum-possible
------- ------ ----- -------- ---------- ----------------------
svm1    vol1   500GB 15564791 96         124518391

• files  -  current inode or file count limit.
• files-used  -  number of inodes used and files in the volume.
• files-maximum-possible  -  maximum possible allowed inode or file count per the volume size.

2. Decide whether to increase the volume or increase the maximum files:

• If current file count is the same as files-maximum-possible, then you must increase the volume size or delete files.
• Increasing the size of the volume will increase the number of available inodes for files if the value was not manually adjusted.
• If increasing the size of the volume is not an option continue with manually increasing the limit. 

3. Determine how much to increase the file count:

Formula:  Current files   * 1.02  = new files capacity.

Example: (15564791 x 1.02 = 15876087

• If you are unsure what your workload growth is, we recommend increasing the current file count by 2%. 
• For migrations, set the value to 2% higher than the source file count.
• You may set it to a higher value if your workload needs are understood.

4. Modify the volume to  increase the file count with the following command:

::> volume modify -vserver svm1 -volume vol1 -files 15876087   
Volume modify successful on volume vol1 of Vserver svm1.
 
::> volume show -vserver svm1 -volume vol1 -fields files
vserver volume files
------- ------ --------
svm1    vol1   15876087

Note: If the file count specified is larger than files-maximum-possible , ONTAP will use the maximum possible:

::*> vol modify -vserver svm1 -volume vol1 -files 125000000                                    
Error: command failed: Unable to set volume attribute "files" for volume "vol1" on Vserver
       "svm1". Reason: The value you entered (125000000) is invalid; maximum inode count cannot
       exceed 124518391.
       Cannot support more than one inode per 4 KB of disk space.

Additional Information

• (OUT OF INODES) ERROR - AutoSupport message
• How to determine the default and maximum inode count for my volume
• Considerations before increasing the file count in ONTAP
• How to automatically set maxfiles in ONTAP to the largest value a volume can hold?
• ONTAP file and directory structure Resolution Guide