[OpenAFS] 1.4 (fs) -> 1.5 (dafs) migration

[Steven Jenkins]

On Fri, Aug 20, 2010 at 10:17 AM, Simon Wilkinson <sxw@inf.ed.ac.uk> wrote:
>
> On 20 Aug 2010, at 15:05, G=E9mes G=E9za wrote:
>
>> We currently have a small cell (2 db and file-servers
>> (1.4.7.dfsg1-6+lenny1), ~50 volumes). But plan to move the user home
>> dirs to afs resulting in >1000 volumes. Being afraid of the fs based
>> startup times we decided to move to a 1.5 based dafs prior to complete
>> the data migration to afs.
>
> If you have sufficient hardware, I would urge you to perform your migrati=
on by using AFS's tools, rather than playing fast and loose with where volu=
mes are mounted. So, bring up some dafs fileservers, and use vos move to mi=
grate volumes from the 1.4 servers to the 1.5 ones. This has the advantage =
that you've got a very simple backout plan if things go wrong for any reaso=
n, as well as allowing you to perform a staged migration without any downti=
me.
>
>> The data is on a Coraid SAN, so it will be
>> simply unmounted from the old fileservers, and mounted to the new ones,
>> but what operations would we need to perform on the ubik data?
>
> If you do want to go down this route, you will need to update the VLDB lo=
cation for every volume that has changed fileservers. vos syncvldb and vos =
syncserv should do this for you - but there will be a period of outage for =
all of your clients.
>

I agree with Simon: using vos move is much better, as it gives you a
staged migration (and backout) plan, increases availability of data,
all without adding the risks involved with re-attaching disks to a
different system.

Steven