Disable file locking on iSCSI drives
Mike Leone
Mike. Leone, <mailto:tur...@mike-leone.com>
PGP Fingerprint: 0AA8 DC47 CB63 AE3F C739 6BF9 9AB4 1EF6 5AA5 BCDF
Photo Gallery: <http://www.flickr.com/photos/mikeleonephotos>
Michael B. Smith
iSCSI is a block-oriented storage protocol.
It doesn’t do locking. NTFS doesn’t do locking.
On Windows, cluster shared volumes (CSV) provide locking. So does Storage Spaces Direct (SSD). On Unix/Linux, it’s rpc.lockd and the file systems that support it.
SMB is a higher-level protocol that provides “operational locking” via a shared library (and in fact, on Unix/Linux it uses rpc.lockd to do so).
Suffice it to say, that unless that “cluster drive” is a CSV or a member of an SSD pool, there are no Windows locks getting in the way of the software.
--
You received this message because you are subscribed to the Google Groups "ntsysadmin" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
ntsysadmin+...@googlegroups.com.
To view this discussion visit
https://groups.google.com/d/msgid/ntsysadmin/CAHBr%2B%2Bg%2BnkRBk3D%3DRx9MD8pUJ%3DAn9wUu3cdNNW-0qXqdPryRXg%40mail.gmail.com.
Mike Leone
iSCSI is a block-oriented storage protocol.
It doesn’t do locking. NTFS doesn’t do locking.
On Windows, cluster shared volumes (CSV) provide locking. So does Storage Spaces Direct (SSD). On Unix/Linux, it’s rpc.lockd and the file systems that support it.
SMB is a higher-level protocol that provides “operational locking” via a shared library (and in fact, on Unix/Linux it uses rpc.lockd to do so).
Suffice it to say, that unless that “cluster drive” is a CSV or a member of an SSD pool, there are no Windows locks getting in the way of the software.
Name
----
PHAMSCLUST27
AddEvictDelay : 60
AdministrativeAccessPoint : ActiveDirectoryAndDns
AutoAssignNodeSite : 0
AutoBalancerMode : 2
AutoBalancerLevel : 1
BackupInProgress : 0
BlockCacheSize : 1024
DetectedCloudPlatform : None
DetectManagedEvents : 1
DetectManagedEventsThreshold : 60
ClusSvcHangTimeout : 135
ClusSvcRegroupStageTimeout : 15
ClusSvcRegroupTickInMilliseconds : 300
ClusterEnforcedAntiAffinity : 0
ClusterFunctionalLevel : 10
ClusterUpgradeVersion : 3
ClusterGroupWaitDelay : 120
ClusterLogLevel : 3
ClusterLogSize : 1536
CrossSiteDelay : 1000
CrossSiteThreshold : 20
CrossSubnetDelay : 1000
CrossSubnetThreshold : 20
CsvBalancer : 1
DatabaseReadWriteMode : 0
DefaultNetworkRole : 3
Description :
Domain : wrk.ads.pha.phila.gov
DrainOnShutdown : 1
DumpPolicy : 1376850201
DynamicQuorum : 1
EnableSharedVolumes : Enabled
FixQuorum : 0
GroupDependencyTimeout : 600
HangRecoveryAction : 6
Id : c9c887c5-7525-4aa8-bac0-bb8a9f34b0ec
IgnorePersistentStateOnStartup : 0
LogResourceControls : 0
LowerQuorumPriorityNodeId : 0
MessageBufferLength : 50
MinimumNeverPreemptPriority : 3000
MinimumPreemptorPriority : 1
Name : PHAMSCLUST27
NetftIPSecEnabled : 1
PlacementOptions : 0
PlumbAllCrossSubnetRoutes : 0
PreferredSite :
PreventQuorum : 0
QuarantineDuration : 7200
QuarantineThreshold : 3
QuorumArbitrationTimeMax : 20
RecentEventsResetTime : 4/27/2021 5:26:39 PM
RequestReplyTimeout : 60
ResiliencyDefaultPeriod : 240
ResiliencyLevel : AlwaysIsolate
RouteHistoryLength : 40
S2DBusTypes : 0
S2DCacheBehavior : Default
S2DCacheDesiredState : Enabled
S2DCacheMetadataReserveBytes : 34359738368
S2DCachePageSizeKBytes : 16
S2DEnabled : 0
S2DIOLatencyThreshold : 10000
S2DOptimizations : 0
SameSubnetDelay : 1000
SameSubnetThreshold : 20
SecurityLevel : 1
SecurityLevelForStorage : 0
SharedVolumeCompatibleFilters : {}
SharedVolumeIncompatibleFilters : {}
SharedVolumeSecurityDescriptor : {1, 0, 4, 128...}
SharedVolumesRoot : C:\ClusterStorage
SharedVolumeVssWriterOperationTimeout : 1800
ShutdownTimeoutInMinutes : 20
UseClientAccessNetworksForSharedVolumes : 2
WitnessDatabaseWriteTimeout : 300
WitnessDynamicWeight : 1
WitnessRestartInterval : 15
EnabledEventLogs : {Microsoft-Windows-Hyper-V-VmSwitch-Diagnostic,4,0xFFFFFFFD,
Microsoft-Windows-SMBDirect/Debug,4, Microsoft-Windows-SMBServer/Analytic,
Microsoft-Windows-Kernel-LiveDump/Analytic}
AnnounceComment :
AnnounceServer : False
AsynchronousCredits : 512
AuditSmb1Access : False
AutoDisconnectTimeout : 15
AutoShareServer : True
AutoShareWorkstation : True
CachedOpenLimit : 10
DurableHandleV2TimeoutInSeconds : 180
EnableAuthenticateUserSharing : False
EnableDownlevelTimewarp : False
EnableForcedLogoff : True
EnableLeasing : True
EnableMultiChannel : True
EnableOplocks : False
EnableSecuritySignature : True
EnableSMB1Protocol : False
EnableSMB2Protocol : True
EnableStrictNameChecking : True
EncryptData : False
IrpStackSize : 15
KeepAliveTime : 2
MaxChannelPerSession : 32
MaxMpxCount : 50
MaxSessionPerConnection : 16384
MaxThreadsPerQueue : 20
MaxWorkItems : 1
NullSessionPipes :
NullSessionShares :
OplockBreakWait : 35
PendingClientTimeoutInSeconds : 120
RejectUnencryptedAccess : True
RequireSecuritySignature : False
ServerHidden : True
Smb2CreditsMax : 8192
Smb2CreditsMin : 512
SmbServerNameHardeningLevel : 0
TreatHostAsStableStorage : False
ValidateAliasNotCircular : True
ValidateShareScope : True
ValidateShareScopeNotAliased : True
ValidateTargetName : True
PresetPathAcl : System.Security.AccessControl.DirectorySecurity
ShareState : Online
AvailabilityType : Clustered
ShareType : FileSystemDirectory
FolderEnumerationMode : Unrestricted
CachingMode : None
LeasingMode : None
SmbInstance : Default
CATimeout : 0
ConcurrentUserLimit : 0
ContinuouslyAvailable : True
CurrentUsers : 8
Description : Web Center - DEV storage
EncryptData : False
IdentityRemoting : False
Infrastructure : False
Name : WCC_DEV
Path : F:\shares\wcc_dev
Scoped : True
ScopeName : DC2_FILESHARE01
SecurityDescriptor : O:BAG:DUD:(A;;FA;;;WD)
ShadowCopy : False
Special : False
Temporary : False
Volume : \\?\Volume{d1e94874-8001-4013-bfc5-762beb43fbbd}\
PSComputerName :
CimClass : ROOT/Microsoft/Windows/SMB:MSFT_SmbShare
CimInstanceProperties : {AvailabilityType, CachingMode, CATimeout, ConcurrentUserLimit...}
CimSystemProperties : Microsoft.Management.Infrastructure.CimSystemProperties
--
From: ntsys...@googlegroups.com <ntsys...@googlegroups.com> On Behalf Of Mike Leone
Sent: Thursday, August 7, 2025 12:58 PM
To: NTSysAdmin <ntsys...@googlegroups.com>
Subject: [ntsysadmin] Disable file locking on iSCSI drives
This confuses me. My devs are reporting a problem with some Oracle software they're using (the WCC product, apparently, the 12c version). And they say Oracle support is telling them:
"In 12c the content server handles all file locking. Any NAS or SAN should have drives mounted without the locking feature enabled. Please check and verify. "
I know about telling the OS about file locking configurations (such as in SMB protocol). But how would I turn off all file locking? Isn't that ... impossible? LOL
This would be on a cluster drive that is mounted via iSCSI. This would be WIn 2019.
--
Mike. Leone, <mailto:tur...@mike-leone.com>
PGP Fingerprint: 0AA8 DC47 CB63 AE3F C739 6BF9 9AB4 1EF6 5AA5 BCDF
Photo Gallery: <http://www.flickr.com/photos/mikeleonephotos>--
You received this message because you are subscribed to the Google Groups "ntsysadmin" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ntsysadmin+...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/CAHBr%2B%2Bg%2BnkRBk3D%3DRx9MD8pUJ%3DAn9wUu3cdNNW-0qXqdPryRXg%40mail.gmail.com.
You received this message because you are subscribed to the Google Groups "ntsysadmin" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ntsysadmin+...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/c3f21838bf52467aa93fe2aa733b1600%40smithcons.com.
Michael B. Smith
You have SMB locking disabled:
EnableOplocks : False
But you also have CSVs enabled:
EnableSharedVolumes : Enabled
If you are sure the volume isn’t a CSV, then it’s a Nutanix question. And I can’t help you with that.
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/CAHBr%2B%2Bj4Hm0176yj%2B_ioxmb22hF%2BcZ-_o16f6Z7DWd5goLeLog%40mail.gmail.com.
Mike Leone
PS C:\Windows\system32>
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/9b3dc43daa934280b9cbdf0346211641%40smithcons.com.
Michael B. Smith
I would interpret it that way too.
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/CAHBr%2B%2BjKBC-k3zi6t7ReDd9pAmPevF1GNmUMY_6JXf2hj8vygw%40mail.gmail.com.
Mike Leone
PS C:\Windows\system32> Get-SmbClientConfiguration
OplocksDisabled : True
UseOpportunisticLocking : False
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/770502c69d484d74917f55f5b3203bc4%40smithcons.com.
Severino Juan Miguel
Hi
> iSCSI is a block-oriented storage protocol.
> It doesn’t do locking. NTFS doesn’t do locking.
Both do locking.
iSCSI uses SCSI reservations, which are required if you have shared LUNs. It is a mess, so vmware implemented other acceleration systems.
NTFS uses locking. Try to delete an open file.
SMB does locking too, in most cases without app intervention for caching: Oplocks, which usually are the mother of all network data corruptions. I saw elsewhere that they were disabled which is... misleading (that setting applies for SMB1 only).
I would check it on the share level (they cannot be disabled on SMB2/3):
get-smbshare <share>|fl -Property *
Search for Leasing Mode. Anything other than None means that Oplocks (and servers blocking each other) are active.
Best regards
Seve
Von: ntsys...@googlegroups.com <ntsys...@googlegroups.com>
Im Auftrag von Michael B. Smith
Gesendet: Donnerstag, 7. August 2025 20:22
An: ntsys...@googlegroups.com
Betreff: RE: [ntsysadmin] Disable file locking on iSCSI drives
-!-!-!- EXTERNAL EMAIL -!-!-!- This email originated from outside of SKAN. Do not click links or open attachments unless you recognize the sender and know the content is safe
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/c3f21838bf52467aa93fe2aa733b1600%40smithcons.com.
Mike Leone
I would check it on the share level (they cannot be disabled on SMB2/3):
get-smbshare <share>|fl -Property *
Search for Leasing Mode. Anything other than None means that Oplocks (and servers blocking each other) are active.
Michael B. Smith
You have two iSCSI initiators, from two different computer systems, connected to a single volume – iSCSI will happily corrupt the volume.
You have two Windows computer connected to a single volume formatted via NTFS – NTFS will happily corrupt the volume.
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/DBBP189MB13403C407F6564CDC64B1DFF832FA%40DBBP189MB1340.EURP189.PROD.OUTLOOK.COM.
Mike Leone
You have two iSCSI initiators, from two different computer systems, connected to a single volume – iSCSI will happily corrupt the volume.
You have two Windows computer connected to a single volume formatted via NTFS – NTFS will happily corrupt the volume.
To view this discussion visit https://groups.google.com/d/msgid/ntsysadmin/b3994cfe53484f44ba5dc78d0ea369aa%40smithcons.com.