Mridang Agarwalla's questions

I've enabled row-caching in for one of my column-families in Cassandra and I'l like to view the cache-hit ratio?

I can see the cache-hit ration metric in Cassandra's OspCenter but it seems to show me the information for the entire cluster? Is there a way I could get this metric?

I have two VMs on a Ubuntu KVM host — www.example.com and uat.example. I can ping and SSH to my UAT server but I can't SSH to my WWW server even though I can ping it. The only thing that is different between the two VMs is the IP group.

• The IP of the UAT server is: 59.134.127.155
• The IP of the WWW server is: 168.127.204.236
• The IP of the host KVM server is: 59.134.127.157

There's a bridge on the host KVM server through which all connections pass.

Here's my /etc/network/interfaces file:

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet manual

# The primary bridge interface
auto br0
iface br0 inet static
      address 59.134.127.157
      netmask 255.255.255.248
      gateway 59.134.127.153
      bridge_ports eth0
      bridge_stp on
      bridge_fd 0
      bridge_maxwait 0

Here's the output of the links on KVM:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether bc:ae:c5:07:0e:d3 brd ff:ff:ff:ff:ff:ff
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/ether bc:ae:c5:07:0e:d3 brd ff:ff:ff:ff:ff:ff
4: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/ether 1e:85:05:ba:0e:2e brd ff:ff:ff:ff:ff:ff
10: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 500
    link/ether fe:16:36:77:d0:17 brd ff:ff:ff:ff:ff:ff
16: vnet2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 500
    link/ether fe:16:36:06:4d:ba brd ff:ff:ff:ff:ff:ff
17: vnet1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 500
    link/ether fe:16:36:cb:8c:44 brd ff:ff:ff:ff:ff:ff

Here are my default routes on the KVM:

59.134.127.152/29 dev br0  proto kernel  scope link  src 59.134.127.157
192.168.122.0/24 dev virbr0  proto kernel  scope link  src 192.168.122.1
default via 59.134.127.153 dev br0  metric 100

I know that something is wrong here because when I do a traceroute from the host server to the UAT server, I get too many hops:

traceroute to www.example.com (168.127.204.236), 30 hops max, 60 byte packets
 1  59-134-127-153.cust.suomicom.fi (79.134.127.153)  4.245 ms  4.400 ms  4.388 ms
 2  * * *
 3  * * *
 ...
 ...
 ...
28  * * *
29  * * *
30  * * *

I can't seem to figure out this issue but if one of you could help me out, I'd be really grateful. I confident that this due to the network configuration in the KVM virtual bridge.

Thanks

We currently have our own servers that have multiple KVM guests. If we ever decide to move to the Amazon EC2, would it possible to simply copy the VM image over or would I need to begin reconfiguring a new VM again on the cloud?

(It might sound silly but I'm still in the process of getting a grasp on the all the virtualisation/cloud stuff)

I'm using KVM for virtualization on a couple of Ubuntu servers but each physical server runs a bunch of VMs. Is there a way I can scale my VMs across physical servers? Does KVM support this? Is there an alternative tool that does this?

I know that VMWare, Citrix and RedHat have their own scalable hyper-visors but they are darn expensive.

Here's an image that illustrate what I mean:

Thank you.

Here's a scenario. We're going to be serving Django site using Apache and Postgres. Nothing more complex than that. In order to handle traffic spikes, I'd like to add more VM guests automatically to handle the extra load. Doesn't EC2 do something like this? This is pretty much what my needs are.

I have a Ubuntu 10.4 system on which I'm running OpenFire but it currently runs as root. How can I make Openfire run as a different user?

Thanks

I had an Ubuntu 10.4 VM running on another Ubuntu KVM host. I'd like to clone this VM but with a new IP address? I know that I would have to stop my VM, clone it, somehow give it a new IP address and then start both. How can I do so without having to SSH into the VM? Would I need to change any other parameters apart from the IP address?

I ran the fdisk -l command to show me all the disks and partitions. Here's the output:

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0003c54f

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          32      248832   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              32      121602   976510977    5  Extended
/dev/sda5              32      121602   976510976   fd  Linux raid autodetect

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e92b3

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1      119513   959986688   83  Linux
/dev/sdb2          119514      121602    16773121    5  Extended
/dev/sdb5          119514      121602    16773120   82  Linux swap / Solaris

Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00089d08

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1          32      248832   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sdc2              32      121602   976510977    5  Extended
/dev/sdc5              32      121602   976510976   8e  Linux LVM

Currently my mounted partitions are /dev/sdb1 and /dev/sdb2. I have some data on the partition /dev/sda2 that I'd like to access. How can i mount this temporarily so that I can access it? Running mount /dev/sda2 gives me an error saying mount: can't find /dev/sda2 in /etc/fstab or /etc/mtab.

I've been trying to install KVM on Ubuntu 11 64bit now. I've been following the docs from the Ubuntu site and everything is going well. I've reached the point where I need to build my VM and it said that I could execute this `sudo ubuntu-vm-builder kvm inteprid to create the VM.

Why is that Intrepid is the latest version available?

I have two static IPs, e.g 220.220.220.220 and 220.220.220.221. I have one network card on the host machine. Can i configure each VM to have it's own IP?

I have a 32 bit version of Ubuntu 10.04.2 running on a server. I need to reinstall a 64 bit edition of Ubuntu. Is it possible to do this remotely via SSH? If yes, how so.

Thanks.

H.

I have Ubuntu running on a server and I use this for all development needs. I'd like to isolate my production and development environments and therefore I thought that it would be good to virtualize my OSs. I'd like to run two Ubuntu OSs on a virtualisation platform. I've never attempted anything of this sort before.

The only virtualisation platform that I know about is VMWare. Is VMWare and KVM the same?

So basically, I'll need to format everything and take it from there. Could some explain to me about how I can do this or point me to a nice document explaining how to do this?

Thanks.