Solaris Zone down

I made a minor configuration change to a Solaris zone and rebooted the zone.

On the way back up it hung with an error message about booting.

I entered zoneadm list -cv with the following results

root@server01 # zoneadm list -cv

ID NAME STATUS PATH BRAND IP
0 global running / native shared
1 licence3-zone running /export/home/zones/licence3-zone native shared
2 licence2-zone running /export/home/zones/licence2-zone native shared
5 licence-zone running /export/home/zones/licence-zone native shared
7 licence1-zone running /export/home/zones/licence1-zone native shared
21 la-zone running /export/home/zones/la-zone native shared
23 build-machine down /export/home/zones/build-machine native shared
24 build-2 running /export/home/zones/build-2 native shared
- build-1 installed /export/home/zones/build-1 native shared
root@server01#
Its state was shown as down!

I entered
zoneadm -z build-machine halt
but it failed with a message saying the zone's /tmp directory couldn't be unmounted.

Entering
zoneadm -z build-machine reboot
failed with a similar message.

Entering
zoneadm -z build-machine boot
was the same.

So I traversed the zone's filesystem from the global zone. I'd downloaded some files to the zone's /tmp directory. I deleted the entire contents and entered
zoneadm list -cv
Its state was still shown as down!
I entered zoneadm -z build-macxhine halt, which returned without error. A zoneadm list -cv showed some good news.

root@server01 # zoneadm -z build-machine halt
root@server01 # zoneadm list -cv
ID NAME STATUS PATH BRAND IP
0 global running / native shared
1 licence3-zone running /export/home/zones/licence3-zone native shared
2 licence2-zone running /export/home/zones/licence2-zone native shared
5 licence-zone running /export/home/zones/licence-zone native shared
7 licence1-zone running /export/home/zones/licence1-zone native shared
21 la-zone running /export/home/zones/la-zone native shared
24 build-2 running /export/home/zones/build-2 native shared
- build-machine installed /export/home/zones/build-machine native shared
- build-1 installed /export/home/zones/build-1 native shared
root@server01 #

And it booted successfully. Huzzah!

Well, that's that!

Netmask settings for Solaris 10 Zones

When the zone is created a large number of files are copied into the new zone. However, the netmask file seems to be generated as an empty file.

Consequently, when you enter ifconfig you end up seeing something like:
...
eri0:2: flags=1000843 mtu 1500 index 2
zone zone2
inet 123.123.123.11 netmask ffff0000 broadcast 123.123.123.255
...

Now obviously you can use ifconfig in the global zone to change the netmask setting interactively. That works. However, a reboot wipes that out. So you have to login to the console of the zone and amend the copied netmask file so that it contains a line like:
123.123.123.0 255.255.255.0

Alternatively, you can access the netmasks file via the global zone filesystem.

Changing hostids for Solaris 10 Zones

I found 3 resources on the Internet which discuss changing the hostid of a Solaris instance.

Only two are specifically related to the case of Solaris Zones. The other is a more general "You can change the hostid..." type of resource.

In my experience with Solaris 10 Zones, only one of these methods succeeded.

Initially I attempted the "Dynamic Library Interposition method described by Julien Gabel on his Blog'o thnet. Initially this held promise.

1. I compiled the code
2. I set the environment variable
3. I ran the code

Success!!

I added the environment variable to an existing startup script. It failed!

The error indicated the library was the wrong type! As I had installed the 64-bit version of Solaris 10, I re-built the dynamic library as 64-bit. Received the same error!


At this point, I actually created my zones, following the outline provided by this Zones Tutorial. The tutorial on how to create a Solaris 8 Zone on a Solaris 10 Server describes how to set an attribute of the Zone as the hostid. Perhaps this works when you really do have a Solaris 8 Zone on your Solaris 10 Server, but it didn't work for my Solaris 10 zones on a Solaris 10 Server.


Finally I resorted to the other mechanism for altering hostids described upon Julien Gabel's Blog'o thnet - daemonizing a DTrace script. This did work. In fact it works very well. Much Kudos should be directed towards Brendan Gregg.