vSAN -- What happens to vSAN when vCenter is offline
Article ID: 326583
Updated On:
Products
VMware vSAN
Issue/Introduction
Symptoms:
vCenter is offline due to e.g.:
- vCenter Server ( VM ) is currently being upgraded
- vCenter Server ( VM ) is inaccessible
- vCenter Server ( VM ) is broken
- vCenter Server ( VM ) is being rebooted
vCenter is offline due to e.g.:
- vCenter Server ( VM ) is currently being upgraded
- vCenter Server ( VM ) is inaccessible
- vCenter Server ( VM ) is broken
- vCenter Server ( VM ) is being rebooted
Environment
VMware vSAN (All Versions)
Resolution
There is no impact to vSAN if vCenter is offline or not fully functional in any way.
vSAN will continue to operate normally and Virtual Machines (VMs) will continue to run.
vSAN operates independently from vCenter.
vCenter (= Web Client ) only serves as Management & Monitoring tool for vSAN.
If vCenter (Web Client) is not available, the status of vSAN can be checked by connecting to one of the vSAN Hosts via SSH/Putty:
1.) Verify that all vSAN Hosts are in the Cluster:
Example ( output may vary a little based on versions ) :
The number should reflect the total number of vSAN Hosts which belong to this Cluster.
If you see Sub-Cluster Member Count not reflecting the total number of vSAN Hosts that belong to this Cluster, please open a case with VMware to have this further investigated.
[root@esx1:~] localcli vsan cluster get
Cluster Information:
Enabled: true
Current Local Time: 2020-05-15T09:34:12Z
Local Node UUID: ########-####-####-####-########607f
Local Node Type: NORMAL
Local Node State: AGENT
Local Node Health State: HEALTHY
Sub-Cluster Master UUID: ########-####-####-####-########e3c0
Sub-Cluster Backup UUID: ########-####-####-####-########e3c8
Sub-Cluster UUID: ########-####-####-####-########4900
Sub-Cluster Membership Entry Revision: 5
Sub-Cluster Member Count: 7 *************** > The number should reflect the total number of vSAN Hosts which belong to this Cluster
Sub-Cluster Member UUIDs: ########-####-####-####-########e3c8, ########-####-####-####-########608f, ########-####-####-####-########e3c0, ########-####-####-####-########e5dc, ########-####-####-####-########607f, ########-####-####-####-########6087, ########-####-####-####-########e3d1
Sub-Cluster Membership UUID: ########-####-####-####-########e3c0
Unicast Mode Enabled: true
Maintenance Mode State: OFF
Config Generation: ########-####-####-####-########bcc5 9 2020-05-08T04:43:26.262
2.) Check the Health of all vSAN Objects located on the Cluster
This refers to the Health Status of your data located on the vSAN Datastore.
Option A:
Example: below shows all vSAN Objects (= 40) in the Cluster are healthy.
Additional Infos in regards to listed states in the output below
[root@esx1:~] localcli vsan debug object health summary get
Health Status Number Of Objects
-------------------------------------------------------------------
inaccessible 0
reduced-availability-with-active-rebuild 0
reduced-availability-with-no-rebuild 0
data-move 0
nonavailability-related-incompliance 0
healthy 40
reduced-availability-with-no-rebuild-delay-timer 0
nonavailability-related-reconfig 0
Option B:
state\": 7 ---> "Healthy"
If you see anything else apart from "state\": 7", please open a case with VMware to have this further investigated.
[root@esx1:~] cmmds-tool find -f python | grep CONFIG_STATUS -B 4 -A 6 | grep 'uuid\|content' | grep -o 'state\\\":\ [0-9]*' | sort | uniq -c
40 state\": 7 *************** > Showing that 40 Objects are healthy
3.) Run a shortened Version of the vSAN Healthcheck
Example: below is showing that all Health Test reporting a healthy status ( green )
If you see in the output below any Health Test listed with status "yellow" or "red",
please open a case with VMware to have this further investigated.
[root@esx1:~] localcli vsan health cluster list
Health Test Name Status
-------------------------------------------------- ------
Overall health green
Network green
Hosts with connectivity issues green
vSAN cluster partition green
All hosts have a vSAN vmknic configured green
vSAN: Basic (unicast) connectivity check green
vSAN: MTU check (ping with large packet size) green
vMotion: Basic (unicast) connectivity check green
vMotion: MTU check (ping with large packet size) green
Network latency check green
Data green
vSAN object health green
vSAN object format health green
Cluster green
Advanced vSAN configuration in sync green
vSAN daemon liveness green
vSAN Disk Balance green
Resync operations throttling green
Software version compatibility green
Disk format version green
Physical disk green
Operation health green
Disk capacity green
Congestion green
Component limit health green
Component metadata health green
Memory pools (heaps) green
Memory pools (slabs) green
Capacity utilization green
Storage space green
Read cache reservations green
Component green
What if the most consumed host fails green
Performance service green
Stats DB object green
Stats primary election green
Performance data collection green
All hosts contributing stats green
Stats DB object conflicts green
[root@esx1:~]
vSAN will continue to operate normally and Virtual Machines (VMs) will continue to run.
vSAN operates independently from vCenter.
vCenter (= Web Client ) only serves as Management & Monitoring tool for vSAN.
If vCenter (Web Client) is not available, the status of vSAN can be checked by connecting to one of the vSAN Hosts via SSH/Putty:
1.) Verify that all vSAN Hosts are in the Cluster:
Example ( output may vary a little based on versions ) :
The number should reflect the total number of vSAN Hosts which belong to this Cluster.
If you see Sub-Cluster Member Count not reflecting the total number of vSAN Hosts that belong to this Cluster, please open a case with VMware to have this further investigated.
[root@esx1:~] localcli vsan cluster get
Cluster Information:
Enabled: true
Current Local Time: 2020-05-15T09:34:12Z
Local Node UUID: ########-####-####-####-########607f
Local Node Type: NORMAL
Local Node State: AGENT
Local Node Health State: HEALTHY
Sub-Cluster Master UUID: ########-####-####-####-########e3c0
Sub-Cluster Backup UUID: ########-####-####-####-########e3c8
Sub-Cluster UUID: ########-####-####-####-########4900
Sub-Cluster Membership Entry Revision: 5
Sub-Cluster Member Count: 7 *************** > The number should reflect the total number of vSAN Hosts which belong to this Cluster
Sub-Cluster Member UUIDs: ########-####-####-####-########e3c8, ########-####-####-####-########608f, ########-####-####-####-########e3c0, ########-####-####-####-########e5dc, ########-####-####-####-########607f, ########-####-####-####-########6087, ########-####-####-####-########e3d1
Sub-Cluster Membership UUID: ########-####-####-####-########e3c0
Unicast Mode Enabled: true
Maintenance Mode State: OFF
Config Generation: ########-####-####-####-########bcc5 9 2020-05-08T04:43:26.262
2.) Check the Health of all vSAN Objects located on the Cluster
This refers to the Health Status of your data located on the vSAN Datastore.
Option A:
Example: below shows all vSAN Objects (= 40) in the Cluster are healthy.
Additional Infos in regards to listed states in the output below
[root@esx1:~] localcli vsan debug object health summary get
Health Status Number Of Objects
-------------------------------------------------------------------
inaccessible 0
reduced-availability-with-active-rebuild 0
reduced-availability-with-no-rebuild 0
data-move 0
nonavailability-related-incompliance 0
healthy 40
reduced-availability-with-no-rebuild-delay-timer 0
nonavailability-related-reconfig 0
Option B:
state\": 7 ---> "Healthy"
If you see anything else apart from "state\": 7", please open a case with VMware to have this further investigated.
[root@esx1:~] cmmds-tool find -f python | grep CONFIG_STATUS -B 4 -A 6 | grep 'uuid\|content' | grep -o 'state\\\":\ [0-9]*' | sort | uniq -c
40 state\": 7 *************** > Showing that 40 Objects are healthy
3.) Run a shortened Version of the vSAN Healthcheck
Example: below is showing that all Health Test reporting a healthy status ( green )
If you see in the output below any Health Test listed with status "yellow" or "red",
please open a case with VMware to have this further investigated.
[root@esx1:~] localcli vsan health cluster list
Health Test Name Status
-------------------------------------------------- ------
Overall health green
Network green
Hosts with connectivity issues green
vSAN cluster partition green
All hosts have a vSAN vmknic configured green
vSAN: Basic (unicast) connectivity check green
vSAN: MTU check (ping with large packet size) green
vMotion: Basic (unicast) connectivity check green
vMotion: MTU check (ping with large packet size) green
Network latency check green
Data green
vSAN object health green
vSAN object format health green
Cluster green
Advanced vSAN configuration in sync green
vSAN daemon liveness green
vSAN Disk Balance green
Resync operations throttling green
Software version compatibility green
Disk format version green
Physical disk green
Operation health green
Disk capacity green
Congestion green
Component limit health green
Component metadata health green
Memory pools (heaps) green
Memory pools (slabs) green
Capacity utilization green
Storage space green
Read cache reservations green
Component green
What if the most consumed host fails green
Performance service green
Stats DB object green
Stats primary election green
Performance data collection green
All hosts contributing stats green
Stats DB object conflicts green
[root@esx1:~]
Additional Information
- A blog from VMware mentioned below has given the detailed information to user about it.
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