Listing files in a directory on vSAN File Services takes a long time

Products

• VMware vSAN

Issue/Introduction

• Listing of files in a directory which is part of vSAN NFS File Share may stuck for a long time.
• Listing files take a very long time when other operations like copy/move are in progress.
  
  
• It may appears that the listing operation is stuck.

time du -sh /XXXX/YYYY/
du: cannot access '/XXXX/YYYY/####. ###': No such file or directory
du: cannot access '/XXXX/YYYY/####. ###': No such file or directory
du: cannot access '/XXXX/YYYY/####. ###': No such file or directory

 

Environment

VMware vSAN 8.x

Cause

• This is product limitation with vSANFS 8.x, where it is using 9p as the network protocol.
• READDIR and metadata operations will take a longer time in this protocol. 
  
  
• Below failure events are seen in ganesh logs.

2025-06-04T10:55:38Z : epoch 683aaf85 : ### : ganesha.nfsd-104[::ffff:10.xx.yy.zz] [svc_1407] 268 :vdfs_filehandle_open :FSAL :vdfs_open failed: could not get attributes: No such file or directory (2)
2025-06-04T10:55:38Z : epoch 683aaf85 : ### : ganesha.nfsd-104[::ffff:10.xx.yy.zz] [svc_1408] 268 :vdfs_filehandle_open :FSAL :vdfs_open failed: could not get attributes: No such file or directory (2)

• Packet captures output may show a large number of READDIR operations during the NFS calls.

readdir v4   586  (around 14.5k files)
access v4    122

Resolution

• Recommended to upgrade to VCF 9.x

Note:

• VCF 9.x uses 10p network protocol.
• With VCF 9.0 metadata performance is improved and READDIR performance is partially improved.

 

Additional Information

• There will be enhancements in the future versions of 9.x which will further improve the performance of READDIR operations.