Symptoms

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 are unable 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

Cause

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. 

Resolution

The nfsv4.cleaningInterval value can be lowered to reduce the time the NAS server holds the locks. Confirm what the current value of nfsv4.cleaningInterval is. 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, for example 30 seconds. root@none spa:/cores/service/user# svc_nas ALL -param -facility nfsv4 -modify cleaningInterval -v 30 SPA : done SPB : done Confirm that the value is 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 affects 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).

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