Re: Can /var be on a separate partition?

[Sven Gaerner <sgaerner@xxxxxxx>]

On Thu, May 09, 2013 at 10:26:58PM -0400, Pierre Abbat wrote:
> On Thursday, May 09, 2013 16:06:09 Sven Gaerner wrote:
> > AFAIR there was a thread on the mailing list with some recommendations how
> > to configure the PFS when it is placed on an SSD. Reblock and rebalance
> > should be run less frequent than it is configured by default.
> 
> I thought there was such a thread, but I don't find it. How often should they 
> be run?

The thread is available here:
  http://leaf.dragonflybsd.org/mailarchive/users/2011-05/msg00134.html

And Matt's suggestions:
  http://leaf.dragonflybsd.org/mailarchive/users/2011-05/msg00043.html

Here are the suggestions regarding the PFS configuration quoted from the second
mail.

    If you are going to run HAMMER on the SSD then you also have to
    manage the reblocking operation(s) on the PFSs.  I would completely
    disable the 'recopy' function by commenting it out and I would adjust
    the reblocking parameters to spend 1 minute every 5 days instead of
    5 minutes every 1 day.

    Everything else can be left as-is.  You can also leave history enabled.
    nohistory will actually generate more write activity.  Though you do have
    to be careful about the retention time due to the limited amount of space
    available on the SSD, so you might want to adjust the snapshot interval
    down from 60d to 10d or something like that.  History is one of HAMMER's
    most important features, it is best to leave it on for all primary
    information storage.  I usually turn it off only for things like
    /usr/obj.

    Most of these parameters are controlled via 'hammer viconfig <pfs>'.
    You want to adjust the config for each mounted PFS and for '/'.


Sven