HAMMER de-dup in master

Siju George sgeorge.ml at gmail.com
Mon Nov 8 22:59:38 PST 2010

On Mon, Nov 8, 2010 at 5:05 PM, Ilya Dryomov <idryomov at gmail.com> wrote:
> On Mon, Nov 08, 2010 at 01:43:33PM +0530, Siju George wrote:
>> Can Version 5 be considered Production Ready?
>> thanks
>> --Siju
> Yes.  Upgrade to version 5 is needed just to record the fact that
> bytes_free field in layer2 freemap structure is now signed.  It's been a
> signed integer for at least three months now and the upgrade itself is
> harmless.  However you don't need to upgrade unless you have some spare
> backups to try dedup code or you mix HAMMER filesystems created under
> master and stable branches (if you upgrade to V5 and then try mounting
> that upgraded filesystem from stable (2.8) branch, it will refuse to
> mount.

Ok I am running on

2.9-DEVELOPMENT DragonFly v2.7.3.1468.gc4ce4-DEVELOPMENT #29: Mon Nov
8 16:39:43 IST 2010

and now I have

dfly-bkpsrv# hammer version /Backup1
min=1 wip=6 max=5 current=4 description="New undo/flush, faster
flush/sync (DragonFly 2.5+)"
available versions:
    1   NORM    First HAMMER release (DragonFly 2.0+)
    2   NORM    New directory entry layout (DragonFly 2.3+)
    3   NORM    New snapshot management (DragonFly 2.5+)
    4   NORM    New undo/flush, faster flush/sync (DragonFly 2.5+)
    5   NORM    Adjustments for dedup support (DragonFly 2.9+)

It is a backup server so Data is very important ;-)
I have pfses running with mirror-stream between the first and second disks.

So as when I upgraded from 3 to 4 I guess these steps will be the
right thing to do?

1) Stop all Mirror Stream Processes
2) Upgrade the disk containing the slave pfses to hammer  ver 5
3) Upgrade the disk containing the master pfses to hammer ver 5
4) Re start mirror-stream processes

After I upgrade the mother Filesystem should I induvidually upgrade
the pfses too?

Thanks :-)


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