Migration from one HN to another

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Revision as of 15:46, 11 August 2007 by Mhammett (talk | contribs) (Add to the howto page)
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I just wanted to get the content out there. Could someone pretty this thing up?

The vzmigrate script is used to migrate a Virutal Environment from one Hardware Node to another.

You first have to setup SSH to permit the old HN to be able to login to the new HN without a password prompt. Run the following on the old HN.

[root@OpenVZ ~]# ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): Created directory '/root/.ssh'. Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /root/.ssh/id_rsa. Your public key has been saved in /root/.ssh/id_rsa.pub. The key fingerprint is: 74:7a:3e:7f:27:2f:42:bb:52:4c:ad:55:31:6f:79:f2 root@OpenVZ.ics.local [root@OpenVZ ~]# cd .ssh/ [root@OpenVZ .ssh]# ls -al total 20 drwx------ 2 root root 4096 Aug 11 09:41 . drwxr-x--- 5 root root 4096 Aug 11 09:40 .. -rw------- 1 root root 887 Aug 11 09:41 id_rsa -rw-r--r-- 1 root root 231 Aug 11 09:41 id_rsa.pub [root@OpenVZ .ssh]# scp id_rsa.pub root@10.1.5.6:./id_rsa.pub The authenticity of host '10.1.5.6 (10.1.5.6)' can't be established. RSA key fingerprint is 3f:2a:26:15:e4:37:e2:06:b8:4d:20:ee:3a:dc:c1:69. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '10.1.5.6' (RSA) to the list of known hosts. root@10.1.5.6's password: id_rsa.pub 100% 231 0.2KB/s 00:00

Run the following on the new HN.

[root@Char ~]# cd .ssh/ [root@Char .ssh]# touch authorized_keys2 [root@Char .ssh]# chmod 600 authorized_keys2 [root@Char .ssh]# cat ../id_rsa.pub >> authorized_keys2 [root@Char .ssh]# rm ../id_rsa.pub rm: remove regular file `../id_rsa.pub'? y

Run the following on the old HN.

[root@OpenVZ .ssh]# ssh -2 -v root@10.1.5.6 OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to 10.1.5.6 [10.1.5.6] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/id_rsa type 1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3 debug1: match: OpenSSH_4.3 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_3.9p1 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-cbc hmac-md5 none debug1: kex: client->server aes128-cbc hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug1: Host '10.1.5.6' is known and matches the RSA host key. debug1: Found key in /root/.ssh/known_hosts:1 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,gssapi-with-mic,password debug1: Next authentication method: gssapi-with-mic debug1: An invalid name was supplied Cannot determine realm for numeric host address

debug1: An invalid name was supplied Cannot determine realm for numeric host address

debug1: Next authentication method: publickey debug1: Offering public key: /root/.ssh/id_rsa debug1: Authentications that can continue: publickey,gssapi-with-mic,password debug1: Offering public key: /root/.ssh/id_rsa debug1: Server accepts key: pkalg ssh-rsa blen 149 debug1: read PEM private key done: type RSA debug1: Authentication succeeded (publickey). debug1: channel 0: new [client-session] debug1: Entering interactive session. Last login: Thu Aug 9 16:41:30 2007 from 10.1.5.20 [root@Char ~]# exit

Now that the vzmigrate script will function, a little bit on vzmigrate.

This program is used for VE migration to another node Usage: vzmigrate [-r yes|no] [--ssh=<options>] [--keep-dst] [--online] [-v]

       destination_address <VEID>

Options: -r, --remove-area yes|no

       Whether to remove VE on source HN for successfully migrated VE.

--ssh=<ssh options>

       Additional options that will be passed to ssh while establishing
       connection to destination HN. Please be careful with options
       passed, DO NOT pass destination hostname.

--keep-dst

       Do not clean synced destination VE private area in case of some
       error. It makes sense to use this option on big VE migration to
       avoid syncing VE private area again in case some error
       (on VE stop for example) occurs during first migration attempt.

--online

       Perform online (zero-downtime) migration: during the migration the
       VE hangs for a while and after the migration it continues working
       as though nothing has happened.

-v

       Verbose mode. Causes vzmigrate to print debugging messages about
       its progress (including some time statistics).

Here is an example of migrating VE 101 from the current HN to one at 10.1.5.6:

[root@OpenVZ .ssh]# vzmigrate 10.1.5.6 101 OPT:10.1.5.6 Starting migration of VE 101 on 10.1.5.6 Preparing remote node Initializing remote quota Syncing private Syncing 2nd level quota Turning quota off Cleanup