NFS Datastore Temporarily Reports Reduced Capacity Before Returning to Original Size
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NFS Datastore Temporarily Reports Reduced Capacity Before Returning to Original Size

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Article ID: 428302

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

  • An NFS datastore intermittently reports reduced total capacity and later reflects its original size without any manual intervention.
  • During the period of reduced reported capacity, virtual machines hosted on the datastore may experience write failures or outages due to the datastore reporting no available free space.

    In /var/run/log/hostd.log below events will be seen.
    2026-01-11T16:40:50.695Z In(166) Hostd[2100004]: [Originator@6876 sub=Libs opID=778d1e59 sid=529354e4 user=vpxuser] Refresh: Volume AMS03-XXXXXX-SSBIP1XXXXXXXX
    2026-01-11T16:40:50.696Z In(166) Hostd[2100004]: [Originator@6876 sub=Libs opID=778d1e59 sid=529354e4 user=vpxuser] SlowRefresh: path /vmfs/volumes/515cfc44-f8db54b9 total blocks 11091194445824 used blocks
    11015688564736forceRefresh = 0
    2026-01-11T16:40:50.696Z In(166) Hostd[2100004]: [Originator@6876 sub=Libs opID=778d1e59 sid=529354e4 user=vpxuser] Refresh: Done. Volume AMS03-XXXXXX-SSBIP1XXXXXXXX 1 vaaiSupport 2
    2026-01-11T16:40:50.697Z In(166) Hostd[2100004]: [Originator@6876 sub=Hostsvc.Datastore opID=778d1e59 sid=529354e4 user=vpxuser] CheckIfCapacityChanged: Datastore fsf-amsxxxx-fz.service.xxxxx.com:/xxx
    2SExxxxx7_153/xxx now has capacity 11091194445824
    --
    2026-01-11T17:10:50.769Z In(166) Hostd[2100013]: [Originator@6876 sub=Libs opID=778d2984 sid=529354e4 user=vpxuser] Refresh: Volume AMS03-XXXXXX-SSBIP1XXXXXXXX
    2026-01-11T17:10:50.770Z In(166) Hostd[2100013]: [Originator@6876 sub=Libs opID=778d2984 sid=529354e4 user=vpxuser] SlowRefresh: path /vmfs/volumes/515cfc44-f8db54b9 total blocks 11091192651776 used blocks
    11015688564736forceRefresh = 0
    2026-01-11T17:10:50.770Z In(166) Hostd[2100013]: [Originator@6876 sub=Libs opID=778d2984 sid=529354e4 user=vpxuser] Refresh: Done. Volume AMS03-XXXXXX-SSBIP1XXXXXXXX accessible 1 vaaiSupport 2
    2026-01-11T17:10:50.772Z In(166) Hostd[2100013]: [Originator@6876 sub=Hostsvc.Datastore opID=778d2984 sid=529354e4 user=vpxuser] CheckIfCapacityChanged: Datastore fsf-amsxxxx-fz.service.xxxxx.com:/xxx
    2SExxxxx7_153/xxx now has capacity 11091192651776
    --
    2026-01-11T17:40:50.845Z In(166) Hostd[2100017]: [Originator@6876 sub=Libs opID=778d3583 sid=529354e4 user=vpxuser] Refresh: Volume AMS03-XXXXXX-SSBIP1XXXXXXXX
    2026-01-11T17:40:50.846Z In(166) Hostd[2100017]: [Originator@6876 sub=Libs opID=778d3583 sid=529354e4 user=vpxuser] SlowRefresh: path /vmfs/volumes/515cfc44-f8db54b9 total blocks 11091190923264 used blocks
    11015688564736forceRefresh = 0
    2026-01-11T17:40:50.846Z In(166) Hostd[2100017]: [Originator@6876 sub=Libs opID=778d3583 sid=529354e4 user=vpxuser] Refresh: Done. Volume AMS03-XXXXXX-SSBIP1XXXXXXXX accessible 1 vaaiSupport 2
    2026-01-11T17:40:50.847Z In(166) Hostd[2100017]: [Originator@6876 sub=Hostsvc.Datastore opID=778d3583 sid=529354e4 user=vpxuser] CheckIfCapacityChanged: Datastore fsf-amsxxxx-fz.service.xxxxx.com:/xxx
    2SExxxxx7_153/xxx now has capacity 11091190923264
    2026-01-14T14:04:00.279Z In(166) Hostd[2100001]: [Originator@6876 sub=Vimsvc.ha-eventmgr] Event 65322 : Message on ssxxxxx on xxxxxxx.xxxxx.local in ha-datacenter: There is no more space for virtual disk '/vmfs/volumes/515cfc44-f8db54b9/ssxxxxxx/ssxxxxxx.vmdk'. You might be able to continue this session by freeing disk space on the relevant volume, and clicking Retry. Click Cancel to terminate this session.

    2026-01-14T14:04:00.279Z Db(167) Hostd[2100001]: [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/cc25cd0d-72f65cfe/ssxxxxxx/xxxxxxx.vmx] Setting current question to '29259'

    2026-01-14T14:04:00.279Z In(166) Hostd[2100017]: [Originator@6876 sub=Hostsvc.VmkVprobSource] VmkVprobSource::Post event: (vim.event.EventEx) {

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    key = 156,

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    chainId = 884196176,

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    createdTime = "1970-01-01T00:00:00Z",

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    userName = "",

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    host = (vim.event.HostEventArgument) {

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->       name = "ssxxxxx on xxxxxxx.xxxxx.local",

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->       host = 'vim.HostSystem:ha-host'

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    },

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    eventTypeId = "esx.problem.vmfs.nfs.volume.no.space",

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    arguments = (vmodl.KeyAnyValue) [

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->       (vmodl.KeyAnyValue) {

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->          key = "1",

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->          value = "AMxxx-xxxx-xxxxx-xxxxx-T2-NFS"

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->       }

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    ],

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    objectId = "ha-host",

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: -->    objectType = "vim.HostSystem",

    2026-01-14T14:04:00.279Z In(166) Hostd[2099964]: --> }

    2026-01-14T14:04:00.279Z In(166) Hostd[2100017]: [Originator@6876 sub=Vimsvc.ha-eventmgr] Event 65323 : AMxxx-xxxx-xxxxx-xxxxx-T2-NFS: No space on NFS volume.

Environment

  • VMware Esxi 8.x
  • VMware Esxi 9.x

Cause

At very high utilization levels on NFS datastores (for example, above 95–99%), backend storage systems may initiate internal space-management or metadata operations. During these operations, the free space reported to ESXi may be temporarily impacted. In such conditions, the datastore may appear full, which can result in virtual machine write failures.

Once backend space is reclaimed and the datastore capacity information is refreshed, the datastore should report the expected available free space.

Resolution

 

  • Maintain NFS datastore utilization below 95% to provide sufficient headroom for backend storage metadata operations.

  • Monitor datastore free space trends and configure alerts well before critical thresholds are reached.

 

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