The beauty of LDOM or Oracle VM for SPARC is that resources can be dynamically added or removed from the domains(Primary/Guest). This will help you to perform the load balancing between the guest domains on the physical server. Dynamic resource allocation is only possible if the guest domain operating system is booted.If you add the resource during the guest domain OS start-up, allocation will fail.
Note:Solaris operating system support dynamic resources allocation.
Oracle VM for SPARC Tutorial:
[checklist]
- Installation and Configuring the Primary domain
- Creating Guest Domains
- Configuring I/O Domain
- Dynamically adding/removing Resources (You Are Here)
- Live Migration for Guest Domains
- Adding ISO image to Multiple Guests
- Configuration Backup & Restore
- Removing the LDOM and Services
[/checklist]
Here we will see how to add/remove resources dynamically when the guest domain is up and running.Before performing any resource management, please make sure you have enough resources on the system .(use “# ldm list-devices -a” to find free resources)
1.List the running domains from the control domain aka primary domain.
bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.2% 7h 48m ldom2 active -n---- 5000 4 4G 0.1% 9h 28m ldom2clone active -n---- 5001 8 8G 0.1% 7h 7m
As per the above output,all the domains are in active state.Which means domains are in powered.(Login to the ldoms and verify OS is up or not .)
2.Add four more virtual CPU’s to ldom2 guest domain.
-bash-3.2# ldm add-vcpu 4 ldom2 -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.3% 7h 48m ldom2 active -n---- 5000 8 4G 0.3% 9h 28m ldom2clone active -n---- 5001 8 8G 0.1% 7h 7m
You can see number of vcpu has been increased from 4 to 8 for ldom2.
3.Number CPU’s can added by directly setting the new value.For an example, Currently ldom2 has just 8 vcpu .If you want to add four more, you just give the below command.
-bash-3.2# ldm set-vcpu 12 ldom2 -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.3% 7h 49m ldom2 active -n---- 5000 12 4G 0.1% 9h 29m ldom2clone active -n---- 5001 8 8G 0.1% 7h 8m
4.CPU also can be removed using set command. Currently ldom2 has 12 vcpu’s. If you want to remove 8 from that, just give the below command.
-bash-3.2# ldm set-vcpu 4 ldom2 -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.4% 7h 49m ldom2 active -n---- 5000 4 4G 3.4% 9h 29m ldom2clone active -n---- 5001 8 8G 0.1% 7h 8m -bash-3.2#
5.Removing vcpu also can be done using remove-vpcu command.
-bash-3.2# ldm remove-vcpu 2 ldom2 -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.2% 7h 52m ldom2 active -n---- 5000 2 6G 0.2% 9h 32m ldom2clone active -n---- 5001 8 8G 0.1% 7h 11m -bash-3.2#
6. Dynamic memory management also same like the cpu management. You need to use “memory” keyword instead of “vcpu”. To set the new memory size to the running domain,use the below commands.If the new value size is higher than the current one ,memory will be added .If the new value is lesser than the existing one, memory size will be reduced to the guest domains.
-bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.2% 7h 51m ldom2 active -n---- 5000 4 4G 0.1% 9h 30m ldom2clone active -n---- 5001 8 8G 0.1% 7h 10m -bash-3.2# ldm set-memory 8G ldom2 -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.2% 7h 51m ldom2 active -n---- 5000 4 8G 0.2% 9h 31m ldom2clone active -n---- 5001 8 8G 0.1% 7h 10m
7.We can also use the below method to increase the physical memory of guest domains.
-bash-3.2# ldm add-memory 2G ldom2 -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.3% 7h 51m ldom2 active -n---- 5000 4 10G 0.1% 9h 31m ldom2clone active -n---- 5001 8 8G 0.2% 7h 10m
8. Like remove option in vcpu, remove-memory option is used to reduce the memory size to the guest domain.
-bash-3.2# ldm remove-memory 4G ldom2 -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.4% 7h 52m ldom2 active -n---- 5000 4 6G 0.5% 9h 32m ldom2clone active -n---- 5001 8 8G 0.2% 7h 11m -bash-3.2#
Other resources like virtual disk also can be added on fly to the virtual machine.Here I am creating a ZFS level LUN for test purpose.
-bash-3.2# zfs create -V 25G pool1/uavol1 -bash-3.2# zfs list NAME USED AVAIL REFER MOUNTPOINT pool1 25.4G 248G 31K /pool1 pool1/clonevol1 96.3M 248G 4.75G - pool1/uavol1 25.3G 248G 4.70G - pool1/vol1 25.3G 269G 4.70G -
Adding the disk to virtual disk service. (vds0)
-bash-3.2# ldm add-vdiskserverdevice /dev/zvol/dsk/pool1/uavol1 uavol1@primary-vds0
Assigning the LUN to guest domain from the virtual disk service.
-bash-3.2# ldm add-vdisk uavdisk uavol1@primary-vds0 ldom2
Connect to the server and scan the newly assiged LUN.
-bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 14 4128M 0.2% 8h ldom2 active -n---- 5000 2 6G 0.2% 9h 40m ldom2clone active -n---- 5001 8 8G 0.1% 7h 19m -bash-3.2# telnet 192.168.2.28 5000 Trying 192.168.2.28... Connected to 192.168.2.28. Escape character is '^]'. Connecting to console "ldom2" in group "ldom2" .... Press ~? for control options .. ldom2-208 console login: root Password: # devfsadm # echo |format
To terminate the ldom console, use “ctrl” + “]” key sequence to back to the control domain.
You can also see the lun from the guest domain “OK” prompt. Let me halt the domain and start it.
-bash-3.2# ldm stop-domain ldom2 LDom ldom2 stopped -bash-3.2# ldm start-domain ldom2 LDom ldom2 started
Connect to the guest domain console again.
-bash-3.2# telnet 192.168.2.28 5000
Trying 192.168.2.28...
Connected to 192.168.2.28.
Escape character is '^]'.
Connecting to console "ldom2" in group "ldom2" ....
Press ~? for control options ..
{0} ok devalias
uavdisk /virtual-devices@100/channel-devices@200/disk@0
iso_ldom2 /virtual-devices@100/channel-devices@200/disk@2
vdisk1_dom2 /virtual-devices@100/channel-devices@200/disk@1
vnet0 /virtual-devices@100/channel-devices@200/network@0
net /virtual-devices@100/channel-devices@200/network@0
disk /virtual-devices@100/channel-devices@200/disk@1
virtual-console /virtual-devices/console@1
name aliases
You can see the newly assigned disk in the OBP level as well.So the bottom line is that resource management is very simple and effective in LDOM aka oracle VM for SPARC.
Hope you too liked the Oracle VM for SPARC resource management. Thank you for visiting UnixArena.
Ahmed Yehia says
Dears,
The article is very good but needs some editing to cope with the new versions of commands. and adding the part of binding and saving configuration to be persistent across reboots of CDOM.
Thanks,
Cristian says
Hello,
In case of main controller reboot, ram or vcpu should be saved before? that is, the assigned resources remain persistent?
Thank you, I was looking at your website, very good.