[OmniOS-discuss] ZFS and Usage-creep

[Tim Brown]

I have a question about ZFS usage and how to predictability allocate
space.  I have scoured the web trying to get a good answer, but have
yet to find one.

I am advertising 2TB datastores to our VMware cluster over fiber
channel using comstar.  I use this command to create the dataset.

zfs create -V 2047g vmpool01/datastores/ds01

It all works great but some of my datasets are using far more that the
2047g(more than double in one case).  Here are some examples:

zfs list
NAME                           USED  AVAIL  REFER  MOUNTPOINT
...
vmpool01                      27.4T  20.7T   469K  /vmpool01
vmpool01/datastores           27.4T  20.7T   384K  /vmpool01/datastores
vmpool01/datastores/ds01      3.10T  20.7T  3.10T  -
vmpool01/datastores/ds02      2.06T  21.4T  1.34T  -
vmpool01/datastores/ds03      2.69T  20.7T  2.69T  -
vmpool01/datastores/ds04      2.49T  20.7T  2.49T  -
vmpool01/datastores/ds05      3.69T  20.7T  3.69T  -
vmpool01/datastores/ds06      4.67T  20.7T  4.67T  -
vmpool01/datastores/ds07      2.47T  20.7T  2.47T  -
vmpool01/datastores/ds08      2.06T  20.8T  1.92T  -
...

Can someone explain this to me or is there a document somewhere that
can tell me how to predict the usage?  Thanks.

- Tim
-- 


Tim Brown
Network System Manager
Muskegon Area ISD
http://www.muskegonisd.org
231-767-7237

Always be yourself.
Unless you can be a pirate.
Then always be a pirate.