Dell Unity: NAS server is holding NFSv4 lock for more than 5 minutes after lease period is expired. (User Correctable)

• After an ungraceful client shutdown, NFS locks on affected files may be observed on the Unity NAS server for up to six minutes.
• Other clients will not be able to lock the file until Unity releases the lock. 
• These locks are visible using the svc_lockd command on the Unity system.

root@none spa:/cores/service/user# date ;svc_lockd NAS_Server list
Mon Oct 27 08:43:36 UTC 2025
NAS_Server : commands processed: 1
command(s) succeeded
output is complete


FileSystem: ufs64 rw /.etc SV20000009=536870921 expfsidstr=67fcca47-e0ae-3301-b819-0e0e84d61219  nooplock triggerlevel=0 nocepp nfsv4locking=ADVISORY renamepolicy=CIFS accesspolicy=NATIVE minactfssize=2816  NumTimesFsckHasModifiedFS=0
  inum=9465
    fldp=0x0008c74ba8 Deleg=0 Opens=1 RangeLocks: Mandatory=0 Advisory=0
  inum=9466
    fldp=0x0008c74d00 Deleg=0 Opens=1 RangeLocks: Mandatory=0 Advisory=0
  inum=9468
    fldp=0x0008c75260 Deleg=0 Opens=1 RangeLocks: Mandatory=0 Advisory=0

FileSystem: ufs64 rw /Ghost_NFS01_Official_FS SV2000000a=536870922 expfsidstr=67fccdbd-4304-dbdd-3b8f-00601696feeb  nooplock triggerlevel=512 nocepp nfsv4locking=MANDATORY renamepolicy=CIFS accesspolicy=UNIX minactfssize=2816 thinprovisioning maxsize=204544 hwm=0  NumTimesFsckHasModifiedFS=0
  inum=9465
    fldp=0x0008c753b8 Deleg=0 Opens=1 RangeLocks: Mandatory=1 Advisory=0   <<<<<<<<<<< Lock placed by client on file inode 9465

Command succeeded



root@none spa:/cores/service/user# date ;svc_lockd NAS_Server info fldp=0x0008c753b8
Mon Oct 27 08:43:46 UTC 2025
NAS_Server : commands processed: 1
command(s) succeeded
output is complete


fldp=0x0008c753b8 inum=9465 ref=1 delegp=0x0000000000 totalLocksCount=2 layoutsCount=0
 Global accessMode=[RWd], denyMode=[rwd]
 Open access=RD-WR deny=NONE [NFSv4_Linux NFSv4.2 test_client_OPEN_0x0008577fc8]

 Lock 0x00064-00064:     -SHR-MAND [credp=0x000857dfc8 NFSv4_Linux NFSv4.2 test_client_LOCK_0x000857dfc8]  <<<<<<<<<< byte-range shared mandatory lock

The NFSv4 protocol uses a lease period, during which the server grants a file lock to a client. The client must renew this lease periodically to keep the lock. 

• If a client shuts down unexpectedly, it cannot renew its lease.
• The Unity NAS server waits for the lease period to expire before attempting to reclaim the locks.
• By default, Unity does not release these resources immediately. A hidden parameter, nfsv4.cleaningInterval, defines an additional waiting period.
• The default nfsv4.cleaningInterval value is 300 seconds (5 minutes).
• Therefore, a locked file is released only after the standard lease period plus the 5-minute cleaning interval, resulting in a total waiting time of approximately 5 to 6 minutes. 

To reduce the time the NAS server holds the locks, the nfsv4.cleaningInterval value can be lowered.

• Confirm what's the current value of nfsv4.cleaningInterval. 

root@none spa:/cores/service/user# svc_nas NAS_Server -param -facility nfsv4 -i cleaningInterval -v

NAS_Server :
param nfsv4.cleaningInterval added into the list of visible params

name                    = cleaningInterval
facility_name           = nfsv4
default_value           = 300
current_value           = 300
configured_value        =
param_type              = global
user_action             = none
change_effective        = immediate
range                   = (30,3600)
description             = Time interval in seconds between two successive clean up of orphan states

detailed_description
This param defines how long the server will keep client resources once the client has expired its lease. It is expressed in a count of seconds.

• Modify the nfsv4.cleaningInterval parameter to a lower value like 30 seconds. 

root@none spa:/cores/service/user# svc_nas ALL -param -facility nfsv4 -modify cleaningInterval -v 30
 
SPA : done
SPB : done

• Confirm the value has been set to 30 seconds. 

root@none spa:/cores/service/user# svc_nas NAS_Server -param -facility nfsv4 -i cleaningInterval -v
 
NAS_Server :
param nfsv4.cleaningInterval added into the list of visible params
 
name                    = cleaningInterval
facility_name           = nfsv4
default_value           = 300
current_value           = 30
configured_value        = 30
param_type              = global
user_action             = none
change_effective        = immediate
range                   = (30,3600)
description             = Time interval in seconds between two successive clean up of orphan states
 
detailed_description
This param defines how long the server will keep client resources once the client has expired its lease. It is expressed in a count of seconds.

Note: This is a global parameter and will affect all NAS servers on the Unity system. The change takes effect immediately and does not require a restart of the NAS server or Storage Processor (SP).