Zpool on the bin

Adventures in ZFS: Mirrored Rpool

Mon, 01 Dec 2014 00:00:00 +0000

It always makes sense to have a mirrored rpool for your production systems, however that is not always how they are configured. This really simple procedure is also critical.

Create a Mirrored Zpool

Check the existing devices to identify the one currently in use.

 bash
 
 
zpool status rpool
 pool: rpool
 state: ONLINE
 scan: none requested
config:

 NAME STATE READ WRITE CKSUM
 rpool ONLINE 0 0 0
 c0t5000CCA0436359CCd0 ONLINE 0 0 0

errors: No known data errors

Once we know which one is currently in use, we need to find a different one to mirror onto.

Adventures in ZFS: Splitting a Zpool

Wed, 09 Jul 2014 00:00:00 +0000

Today we are going to go through the process of splitting a zpool. This is not something that you will do often, but when you do it, you must be very precise and do it properly.

Create Our Test Zpool

First we will create a ZFS to hold our disk images.

bash

zfs create rpool/testdisks

Next we will create the disk images.

 bash
 
 
mkfile 1g /rpool/testdisks/disk0
mkfile 1g /rpool/testdisks/disk1
mkfile 1g /rpool/testdisks/disk2
mkfile 1g /rpool/testdisks/disk3

Finally we will create our zpool, which in this case is tank.

Adventures in ZFS: Destroy A Zpool Without Importing

Tue, 01 Jul 2014 00:00:00 +0000

Recently I ran into an issue where I had a zpool that wasn’t imported in a system, and I was unable to import it due to zpool version incompatibilities. This can happen if you are going to a older revision of Solaris or if you are crossing platforms between ZFS and OpenZFS. This posed an interesting problem for me, as how do I destroy a pool that I haven’t imported? There might be a quick command to handle this, but this actually presented another problem, as in my example I actually had a zpool name collision as well (this was the second mirror in an old rpool).

Adventures in ZFS: Rename a Zpool

Mon, 30 Jun 2014 00:00:00 +0000

Renaming a zpool is not as intuitive as I would expect, but it is still pretty simple. We accomplish this through a three step process, export the zpool, import the zpool (using a new name), validate our mountpoints are how we want them (probably using the new zpool name).

Now why might I want to rename it? That is simple, perhaps it is simply for organization or perhaps you already have a zpool by that name, or perhaps you use zpool mirrors as a method of backup (break the mirror rename one side, rebuild mirror with a new disk maintaining the previous copy offline).

Adventures in ZFS: Time Slider is not Expiring Snapshots on Imported Zpools

Tue, 06 Sep 2011 00:00:00 +0000

A few days ago someone contacted me with an interesting issue with regards to the ZFS automatic snapshots, facilitatedby the time slider service.

The Situation

OpenSolaris machine with zpool exported. Time slider was working prior to export.
Solaris 11 Express fresh install with zpool imported.

The Symptoms

Basically the core of the issue was that the zpool was from an OpenSolaris machine, in lieu of doing an upgrade from OpenSolaris to Solaris 11 Express, the zpool was exported and imported into a machine which was already running Solaris 11 Express. Upon the import new snapshots were being created by the time slider service however old ones were not being expired. You can still manually delete snapshots.