ESXi Configuration Backups

Config Backup commands would back up all the Switch,Nic,VLans and all the configurations on the hosts.

Hosts requires a reboot.

vicfg-cfgbackup -s(save)   /tmp/backup
vicfg-cfgbackup -l(load)   /tmp/backup

Storage Identifier & Logs

Stroage Identifier are unique identifer  for each of the stroage devices connected to ESX/ESXi.
NAA:Network Address Authority
T10:any SCSI device
iSCSI IQN :iSCSI qualified name
MPX:Vmware generated,dev that doesn't respond

Stroage Logs:
PSA modules loaded at boot is found in
ESX- /var/log/boot-logs/sysboot.log
ESXi-/var/log/sysboot.log

Critical Stroage events:
ESX :/var/log/vmkernel
ESXi:/var/log/messages

Storage Commands

@esxcfg-nas   :Configure NAS storage
@esxcfg-mpath :Configure and view mutiple storage paths
@esxcfg-rescan:Rescan Lans
@esxcfg-scsidevs:To view all scsi devices that esxi host can see
@esxcfg-swiscsi:Software iscsi device
@esxcfg-volumes:
@vmkiscsi-tool:
@esxcli:Analyzing PSA & Mutlipathing,esxcli gives you the namespaces to dig deep into
Namespaces esxcli:
corestroage :to configure LUN masking or storage path masking.
Network:Network commands
nmp:Configure and view multipathing
swiscsi:configure software ISCSI

@esxcli nmp satp list
@esxcli nmp psp list
@esxcli nmp path list (all path of stroage devices)
@esxcli nmp device list(to view avalible devices)
@vmkload_mod:loads and unloads modules for VMkernel
@vicfg-module or esxcfg-module :to view/load/unload the modules
Note: when a module is enabled it does not take affect until it next reboot.
@vmware-cmd (gives all the operations we can perform on VM)
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esxtop & vscsiStats
@esxtop :Gives stroage latency and throughput.Latency is only provided for iSCSI and FC
@vscsiStats:gives reports on stroage counters from Virtual SCSI device in kernel,per VMDK for all.vscsiStats is only on ESX classic and can be installed on ESXi also
@esxtop d device
@esxtop v per VM stats

Storage terms

VMFS Datastores can be stored onlocal stroage ,FC SAN or iSCSI SAN.You can store VM's on NFS NAS but that doesnt use VMFS.

PSA :Pluggable Storage Architecture is a special layer of VMkernal making maltipathing flexible  and allows
3rd party mutipathing plugins (MPP).PSA takes effect when VMkernal sendsa SCSI command to access data on block device.

MPP:Multi pathing Plugins ( Like EMC Power path)

NMP:Native multipathing plugin is the VMware NMP(Native mutipathing plugin).NMP manages subplugins SATP and PSP

SATP:Storage Array Type Plugins knows how to comminicate with stroage arrays

PSP:Path selection Plugins takes the path to get to the stroage arrays

ALUA:

Notes :
MPP and NMP can  coexist and can be used on a LUN or per array basis.
MPP or NMP job is to discover physical Stroage Devices and determine the "Claim rules" to export the logical device.Claimrule are found in /etc/vmware/esx.conf.Path failover is delegated to SATP.Path Load Balancing is delegated to PSP.

esxtop for 2 hours

#vm-support -s -i 300 -d 7200 will collect logs for 2 hours in the VM support bundle

for i in `seq 1`;do esxtop -a -b -d 5 -n 360 > /vmfs/volumes/host1.csv.$i;done

Private Vlans

Private Vlans:

Evolution of PVLANS :
Vlans=Virtual Lans
1) Layer 2 broadcast Domain segmented into Logical networks.
2) Each Vlan has it own Ip Subnet and layer three device like router or a layer three Switch  is needed to route traffice between Vlans.
VLan ID: 0 to 4095 and if these are not enough for we go for private Vlans.

Private Vlans :
Pvlans segment a vlan into more vlans.PVlans allow us to isolate traffic (at layer2) between machines in the Vlans
Reqirments :DVSWITCH (Enterprise plus)
PVLANS Types:Primary or promiscus,isolated & comminity