In Oracle VM for SPARC,we can migrate the guest domains to another system without any downtime. This is similar to vmotion on VMware ESXi. This feature provides the operational flexibility to the customers who don’t want the system to be down for system maintenance.Prior to the system maintenance ,we can easily move the guest domains to another system without any downtime using this live migration.Once you have completed the system maintenance , you can just migrate the guest domains back to the original systems.
Oracle VM for SPARC Tutorial:
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- Installation and Configuring the Primary domain
- Creating Guest Domains
- Configuring I/O Domain
- Dynamically adding/removing Resources
- Live Migration for Guest Domains (You Are Here)
- Adding ISO image to Multiple Guests
- Configuration Backup & Restore
- Removing the LDOM and Services
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Normally we would allocate the same set of LUNS to source and target machines. The live-migration feature is just only for the Guest domain migration not for the storage.So when the control domains verify the remote system, it will check whether the guest machine storage is accessible or not.
Prerequisites:
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- Network access between Control Domains
- Shared Storage
- Compatible versions of Oracle VM Server for SPARC and Firmware.
- Similar Hardware configuration on both the systems
- Identical Virtual services between the nodes.
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How the migration is happening without any downtime ?
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- Migration has been initiated by one of the control domain root user
- Control domain performs the nessasary check prior to the migration.It checks server compatibitliy,network connnectivity and available resources
- Virtual machine configuration is copied from source to target
- Virtaul machine’s in-memory contents will be copied to target system
- Guest domain will be suspended on source system
- Finally guest will be started on the target system
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Here we will see how we can perform the live migration between two T5140 systems.
1. Login to the source system and list the guest domains.
-bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 12 4128M 0.5% 1d 15h 45m ua1guest active -n---- 5000 12 6G 0.1% 1h 35m -bash-3.2#
2.List the guest domain “ua1guest” bindings.Make sure the remote system should has enough enough resource to handle this guest domains. (Use # ldm list-devices -a)
-bash-3.2# ldm ls-bindings ua1guest
NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME
ua1guest active -n---- 5000 12 6G 0.1% 1h 36m
UUID
7b74fd6b-88ea-c578-d0df-efe202fb8c12
MAC
00:14:4f:f9:87:e7
HOSTID
0x84f987e7
CONTROL
failure-policy=ignore
DEPENDENCY
master=
CORE
CID CPUSET
1 (8, 9, 10, 11, 12, 13, 14, 15)
3 (24, 25, 26, 27, 28, 29, 30, 31)
VCPU
VID PID CID UTIL STRAND
0 8 1 0.2% 100%
1 9 1 0.1% 100%
2 10 1 0.1% 100%
3 11 1 0.0% 100%
4 12 1 0.0% 100%
5 13 1 0.3% 100%
6 14 1 0.0% 100%
7 15 1 0.0% 100%
8 24 3 0.0% 100%
9 25 3 0.0% 100%
10 26 3 0.0% 100%
11 27 3 0.1% 100%
MEMORY
RA PA SIZE
0x10000000 0x10000000 4G
0x400000000 0x110000000 2G
VARIABLES
auto-boot?=false
keyboard-layout=US-English
NETWORK
NAME SERVICE ID DEVICE MAC MODE PVID VID MTU LINKPROP
vnet0 primary-vsw0@primary 0 network@0 00:14:4f:fa:b2:d6 1 1500
PEER MAC MODE PVID VID MTU LINKPROP
primary-vsw0@primary 00:14:4f:fa:12:0e 1 1500
DISK
NAME VOLUME TOUT ID DEVICE SERVER MPGROUP
ua1guestdsk ua1guest@primary-vds0 0 disk@0 primary
VCONS
NAME SERVICE PORT
ua1guest primary-vc0@primary 5000
-bash-3.2#
3.List the source system’s services. You should also have the same services name configured on the target system.
-bash-3.2# ldm list-services
VCC
NAME LDOM PORT-RANGE
primary-vc0 primary 5000-5100
VSW
NAME LDOM MAC NET-DEV ID DEVICE LINKPROP DEFAULT-VLAN-ID PVID VID MTU MODE
primary-vsw0 primary 00:14:4f:fa:12:0e nxge1 0 switch@0 1 1 1500
VDS
NAME LDOM VOLUME OPTIONS MPGROUP DEVICE
primary-vds0 primary ua1guest /dev/rdsk/c4t600144F0C1135B490000530383E50007d0s2
GSTISO ro /export/home/sol-10-u10-ga2-sparc-dvd.iso
-bash-3.2#
4.Now login to target system and check whether the live migration can be done or not.
-bash-3.2# ldm list-services
VCC
NAME LDOM PORT-RANGE
primary-vc0 primary 5000-5100
VSW
NAME LDOM MAC NET-DEV ID DEVICE LINKPROP DEFAULT-VLAN-ID PVID VID MTU MODE
primary-vsw0 primary 00:14:4f:fb:a5:6d nxge1 0 switch@0 1 1 1500
VDS
NAME LDOM VOLUME OPTIONS MPGROUP DEVICE
primary-vds0 primary ua1guest /dev/rdsk/c4t600144F0C1135B490000530383E50007d0s2
-bash-3.2# ldm ls-domain
NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME
primary active -n-cv- SP 8 8G 0.2% 1d 6h 23m
subuldom inactive ------ 4 4G
-bash-3.2#
As per the above command output, all the services names are matching with source system. We also have the enough resource to handle the guest domain.
5. Login to the source system’s control domain and execute the migration command.It will prompt for target system root password. Just enter continue.
-bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 12 4128M 0.3% 1d 15h 53m ua1guest active -n---- 5000 12 6G 0.0% 1h 42m -bash-3.2# ldm migrate ua1guest 192.168.2.29 Target Password:
6.Login to the target system’s control domain and list the domains.
-bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 8 8G 0.2% 1d 6h 23m subuldom inactive ------ 4 4G -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 8 8G 14% 1d 6h 26m ua1guest bound -----t 5000 1 6G subuldom inactive ------ 4 4G -bash-3.2#
In the above output, you can see , “ua1guest domain is copying from the source system.
7.In the source system , you may get a warning like the below one after successfully completion of live-migration.
Domain ua1guest is not running an operating system that is compatible with the latest migration functionality. Upgrading to the latest software will remove restrictions on a migrated domain that are in effect until it is rebooted. Consult the product documentation for a full description of these restrictions. -bash-3.2#
8.In target system, the guest domain flag will be changed from “t” to “n” .
-bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 8 8G 44% 1d 6h 28m ua1guest bound -----t 5000 1 6G subuldom inactive ------ 4 4G -bash-3.2# ldm ls-domain NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- SP 8 8G 0.9% 1d 6h 32m ua1guest active -n---- 5000 12 6G 0.1% 12h 11m subuldom inactive ------ 4 4G -bash-3.2#
9.You didn’t believe the live migration ? Let me double check.
-bash-3.2# telnet localhost 5000 Trying ::1... telnet: connect to address ::1: Network is unreachable Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. Connecting to console "ua1guest" in group "ua1guest" .... Press ~? for control options .. UAMIGD console login: root Password: Last login: Thu Feb 20 00:50:39 on console Oracle Corporation SunOS 5.10 Generic Patch January 2005 # uptime 2:02am up 1:43, 1 user, load average: 0.00, 0.02, 0.01 #
As per the above command output, nothing has happened to the guest domain. The system is up from last 2hr. The migration has been initiated few minutes back.So the guest domain was up during the migration time too.
Hope you will also give a try on LDOM guest live migration . Thank you for visiting UnixArena.