Unable to extend vSAN virtual disk (vmdk) beyond 40 TB.
Article ID: 426704
Updated On:
Products
Issue/Introduction
Administrators may encounter an error when attempting to extend a thick virtual machine disk (VMDK) residing on a vSAN datastore to 40 TB and beyond, despite the underlying storage cluster having sufficient free space and components.
UI task fails with an error "msg.disklib.INVAL or 22 (Invalid argument)"
VMware.log:
2026-01-20T22:11:12.195Z In(05) worker-3762905 - DISKLIB-LIB : Pre-growing disk '/vmfs/volumes/vsan:525a9f0a1cf62584-b8b3665a3cc72eb8/03166d69-3726-ce79-6970-############/vm-name.vmdk': new capacity = 85899345920 sectors =====> 40 TB
2026-01-20T22:11:12.211Z Er(02) worker-3762905 - OBJLIB-VSANOBJ: VsanObjIoctl: ioctl IOCTLCMD_VMFS_SET_FILE_LENGTH(3004) failed on 10166d69-7fce-0931-febc-############: Invalid argument (0x######).
2026-01-20T22:11:12.211Z Er(02) worker-3762905 - DISKLIB-FLAT : Unable to set object length: Invalid argument (#######)
Hostd.log:
2026-01-20T22:11:12.212Z Db(167) Hostd[2102597]: [Originator@6876 sub=Vigor.Vmsvc.vm:/vmfs/volumes/681e85d3-8af2a8d9-949e-############/mbpimswap001/vm-name.vmx] Extend disk message: The disk extend operation failed: Invalid argument
2026-01-20T22:11:12.212Z Db(167) Hostd[2102566]: -->
2026-01-20T22:11:12.212Z In(166) Hostd[2102600]: [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/681e85d3-8af2a8d9-949e-############/mbpimswap001/vm-name.vmx opID=mkg2lfpi-2321534-auto-1drb3-h5:70179369-80-01-7e-d8a5 sid=52d4da02 user=vpxuser:######\##########] Reconfigure failed: N3Vim5Fault20GenericVmConfigFault9ExceptionE(Fault cause: vim.fault.GenericVmConfigFault
Clomd.log:
2026-01-20T22:11:12.199Z No(29) clomd[2099941]: [Originator@6876] CLOMLogConfigurationPolicy: Object size 43980465111040 bytes with policy: (("stripeWidth" i1) ("cacheReservation" i0) ("proportionalCapacity" i100) ("hostFailuresToTolerate" i1) ("forceProvisioning" i0) ("spbmProfileId" "442ed2d2-a561-417b-8be6-############") ("spbmProfileGenerationNumber" l+0) ("storageType" "Allflash") ("replicaPreference" "Capacity") ("iopsLimit" i0) ("checksumDisabled" i0) ("CSN" l19) ("spbmProfileName" "vSAN-ThickProv-FTT1 ESA RAID5"))
2026-01-20T22:11:12.199Z No(29) clomd[2099941]: [Originator@6876] CLOMFetchDOMEvent: Queueing workitem for 10166d69-7fce-0931-febc-############ type: CHANGE
2026-01-20T22:11:12.204Z No(29) clomd[2099941]: [Originator@6876] CLOM_PostWorkItem: Posted a work item opID:1804289583 for 10166d69-7fce-0931-febc-############ group: 03166d69-3726-ce79-6970-############ Type: CHANGE delay 0 (Success)
2026-01-20T22:11:12.204Z No(29) clomd[2099941]: [Originator@6876 opID=1804289583] CLOMProcessWorkItem: Op CHANGE starts:1804289583
2026-01-20T22:11:12.207Z No(29) clomd[2099941]: [Originator@6876 opID=1804289583] CLOMReconfigure: Reconfiguring 10166d69-7fce-0931-febc-############ workItem type CHANGE
2026-01-20T22:11:12.211Z Cr(26) clomd[2099941]: [Originator@6876 opID=1804289583] CLOMValidateAndUpdateTargetPolicy: Object requires reservation of 44860074413260 bytes, but the max reservation supported is 44777933163724 bytes.
2026-01-20T22:11:12.212Z Cr(26) clomd[2099941]: [Originator@6876 opID=1804289583] CLOMReconfigure: exit: obj 10166d69-7fce-0931-febc-############ transiantCapGenerated - total: 0, site1: 0, site2: 0, workItem type CHANGE configDelay 0 newConfigGenerated 0 newCompWitnessOnly 0 status Bad parameter
2026-01-20T22:11:12.212Z Cr(26) clomd[2099941]: [Originator@6876 opID=1804289583] CLOM_Diagnose: The maximum object size supported by the policy is 44777933163724 bytes.
2026-01-20T22:11:12.212Z Cr(26) clomd[2099941]: [Originator@6876 opID=1804289583] CLOMProcessWorkItem: Failed to generate configuration: Bad parameter
2026-01-20T22:11:12.213Z No(29) clomd[2099941]: [Originator@6876 opID=1804289583] CLOM_PublishResyncBytes: No more work for 10166d69-7fce-0931-febc-############ (Success), reset queued resync bytes to 0
2026-01-20T22:11:12.214Z No(29) clomd[2099941]: [Originator@6876 opID=1804289583] CLOMProcessWorkItem: Op ends:1804289583
Environment
vSAN ESA
vSAN ESA 9.x
vSAN ESA 8.x
Cause
Currently vSAN has a reservation limit of 40 TB for thick disks, hence a reservation beyond 40TB or 44777933163724 bytes results in an error.
Resolution
Create thin provisioned drives when the required disk size exceeds 40TB.
If the requirement is for thick-provisioned drives exceeding 40TB, create multiple disks of size lower than 40TB at vSphere level and utilize LVM within the guest operating system to form a single large volume. The upper limit for the size of a disk in the guest operating system is capped at 62 TB.
For example, if the need is 50 TB thick provisioned drive, create two 25TB thick provisioned VMDK and in the guest OS create LVM in Linux or dynamic disk in Windows to form a single large 50TB volume.
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