ZFS is a memory hog.   you need 1 GB of RAM for each TB of disk.

On 3/1/2018 1:49 AM, Walter Parker wrote:
Forgot to CC the list.

On Wed, Feb 28, 2018 at 10:13 PM, Walter Parker <walt...@gmail.com> wrote:

Thank you for the backup script.

By my calculations, 2G should be enough. If I limit the ARC cache to 1G,
that leaves 1G for applications & kernel memory. As I'm not serving the 6TB
drive up as a file server, but using it for one specific task (to receive
the backups from one host) I figure that I don't need lots of memory. ZFS
as a quick file server or busy server needs lots of memory to be quick.
I've seen testing showing ZFS doing fast file copies on as little as 768M
total system after proper memory tuning.

I need ZFS because it is the only file system that can receive incremental
ZFS snapshots and apply them. I have not setup the ZFS backup software yes,
so I'm just using rsnapshot. First time it ran, it filled all 1G of the
cache. I rebooted the firewall afterwards and now ZFS with 60-100M of usage
(the amount of data that rsync updates on a daily basis is pretty small).
Right now, the data from the other server is ~8.8G, compressed to 1.7G with
lz4.

When I get the full backup running, I will be ~1.5TB in size. ZFS
snapshots should be pretty small and quick (as it can send just the data
that was updated without having to walk the entire filesystem). An rsync
backup would have to walk the whole system to find all of the changes. Most
of the data on the system doesn't change (as it is a media library).

I'll post back more results if people are interested, after I get the
backup software working (I'm thinking about using ZapZend).


Walter



On Wed, Feb 28, 2018 at 8:54 PM, ED Fochler <soek...@liquidbinary.com>
wrote:

I feel like I'm late in responding to this, but I have to say that 2GB of
RAM doesn't seem like nearly enough for a 6TB zfs volume.  ZFS is great in
a lot of ways, but is a RAM consuming monster.  For something RAM limited
like the 2220 I'd use a different, simpler file format.  Then I'd use rsync
based snapshots.

Here's my personal backup script.  :-)  I haven't tried it FROM pfsense,
but I've used it to back up pfsense.

         ED.





On 2018, Feb 21, at 12:23 PM, Walter Parker <walt...@gmail.com> wrote:

Hi,

I have 2.4.2 installed on an SG-2220 from Netgate [nice box]. I just
bought
a 6TB powered USB drive from Costco and it works great (the drive has
its
own power supply and a USB hub). I want to use it take ZFS backups from
my
home server.

I edited /boot/loader.conf.local and /etc/rc.conf.local to load ZFS on
boot
and created a pool and a file system. That worked, but the memory ran
low
so I restricted the ARC cache to 1G to keep a bit more memory free and
rebooted. When the system rebooted it did not remount the pool (and
therefore the file system) because the pool what marked as in use by
another system (itself). That means that the pool was not properly
exported/umounted at shutdown.

Taking a quick look a rc.shutdown, I notice that it calls a customized
pfsense shutdown script at the beginning and then exits. Is there a good
place in the configuration where I can put/call the proper zfs shutdown
script so that the pool is properly stopped/exported so that it imports
correctly on boot?


Walter

--
The greatest dangers to liberty lurk in insidious encroachment by men of
zeal, well-meaning but without understanding.   -- Justice Louis D.
Brandeis
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--
The greatest dangers to liberty lurk in insidious encroachment by men of
zeal, well-meaning but without understanding.   -- Justice Louis D. Brandeis




--
Best Regards
Curtis Maurand
Principal
Xyonet Web Hosting
mailto:cmaur...@xyonet.com
http://www.xyonet.com
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