SmartOS: how to clone a KVM machine

Get the disk0 filesystem of the VM to clone.

vmadm get uuid-originvm | json disks

[
  {
    "path": "/dev/zvol/rdsk/zones/uuid-originvm-disk0",
    "boot": true,
    "model": "virtio",
    "media": "disk",
    "image_size": 10240,
    "image_uuid": "d8e65ea2-1f3e-11e5-8557-6b43e0a88b38",
    "zfs_filesystem": "zones/uuid-originvm-disk0",
    "zpool": "zones",
    "size": 10240,
    "compression": "off",
    "refreservation": 10240,
    "block_size": 8192
  }
]

Take a snapshot

zfs snapshot zones/uuid-originvm-disk0@toclone

Create a json file in order to create the new VM.
vi targetvm.json
Please note: there are no disks.

{

  "alias": "targetvm",

  "hostname": "targetvm",

  "dns_domain": "mydomain.it",

  "brand": "kvm",

  "resolvers": [

    "192.168.0.2"

  ],

  "ram": "2048",

  "vcpus": "2",

  "nics": [

    {

      "nic_tag": "admin",

      "ip": "192.168.0.201",

      "netmask": "255.255.255.0",

      "gateway": "192.168.0.1",

      "model": "virtio",

      "primary": true

    }

  ]

}

vmadm create -f targetvm.json

Let's clone the filesystem of the origin VM.

zfs clone zones/uuid-originvm-disk0@toclone zones/uuid-targetvm-disk0

Create a json in order to add a disk to the new VM.
vi adddisk.json

{

   "add_disks": [

      {

          "media": "disk",

          "model": "virtio",

          "boot": true,

          "nocreate": true,

          "size": 10240,

          "path": "/dev/zvol/rdsk/zones/435ca788-4935-ead3-f4e4-94e6eb7dd4b6-disk0"

      }

   ]

}

Let's add the disk to the newly created VM.

vmadm stop uuid-targetvm -F

vmadm update uuid-targetvm -f adddisk.json

This is important.

zfs promote  zones/uuid-targetvm-disk0

From man zfs:

zfs promote clone-filesystem

    Promotes a clone file system to no longer be dependent on its "ori-

    gin" snapshot. This makes it possible to destroy  the  file  system

    that  the clone was created from. The clone parent-child dependency

    relationship is reversed, so that the origin file system becomes  a

    clone of the specified file system.

    The  snapshot  that  was cloned, and any snapshots previous to this

    snapshot, are now owned by the promoted clone. The space  they  use

    moves  from the origin file system to the promoted clone, so enough

    space must be available to  accommodate  these  snapshots.  No  new

    space  is  consumed  by this operation, but the space accounting is

    adjusted. The promoted clone must not have any conflicting snapshot

    names  of  its own. The rename subcommand can be used to rename any

    conflicting snapshots.

tomcat sloooow to start, smartos, kvm: urandom?

A fresh installation of CentOS 7 in a SmartOS KVM virtual machine using a dataset (     image_uuid: d8e65ea2-1f3e-11e5-8557-6b43e0a88b38).
CentOS updated just after the installation.

• apache-tomcat-7.0.64
• Java(TM) SE Runtime Environment (build 1.7.0_80-b15)

I noticed that Tomcat, at startup was very very very, help me, very slow to start.

I used strace to look at what was happening (even if I don't understand anything).

I got a lot of

[pid  1279] futex(0x7f5a880a7154, FUTEX_WAIT_BITSET_PRIVATE, 1, {348, 455527976}, ffffffff) = -1 ETIMEDOUT (Connection timed out)

[pid  1279] futex(0x7f5a880a7128, FUTEX_WAKE_PRIVATE, 1) = 0

Just googled around. I found something similar.

So the solution is: to add the following option to java in the tomcat startup script

-Djava.security.egd=file:/dev/urandom

 (like CATALINA_OPTS="$CATALINA_OPTS -Djava.security.egd=file:/dev/./urandom").

Who knows?

smartos: add additional disk from a different zpool

I have 2 zpools

  pool: zones
  pool: zpool_repos


I want to add to a KVM machine a disk living not in the zones pool, but in the other one.

My VM is already provisioned.
First of all I must stop it.

vmadm stop <uuid>

Now I create a ZFS volume

zfs create -V 10G zpool_repos/mykvmdata

Now I create a json file for the update

vi adddisk.json

{
   "add_disks": [
      {
          "media": "disk",
          "model": "virtio",
          "nocreate": "true",
          "boot": false,
          "path": "/dev/zvol/rdsk/zpool_repos/uuu"
      }
   ]
}

Now I update the KVM machine.

vmadm update 5942c90f-ecbb-4acd-822f-43e1901e2eb6 -f dataset.json

That's all.
Now, after starting the virtual machine, from inside it, I must partition the new disk (i.e. /dev/vdb in linux) and format.

SmartOS, kvm, vnc and keyboard

SmartOS.
I have had problems with the keyboard using VNC to connect to a KVM guest.
Keyboard mapping I mean.
The solution working for me was:

vmadm update <uuid> qemu_extra_opts="-k it"

centos kvm console

To enable console access from the host command line to a CentOS guest, this was an useful link