On 8/5/2018 11:58 PM, Ximeng Guan wrote:
> Hello,
>
> We have one cell covering two sites. The WAN bandwidth between the two
> sites is relatively low, so we use volume replication to speed up the
> access. 
> 
> Those replicated volumes are often large in size. So replication to the
> remote site is an operation whose cost cannot be neglected.
> 
> Now with RW volumes at site A and their RO replication on servers at
> site B, we want to bring up a new file server at site B to balance the
> load. In other words we would like to “offload” a majority of the RO
> volumes from one server to a different server at Site B, without
> touching their RW masters at Site A.
> 
>[...]>
> I wonder if there is a way to directly transfer those RO volumes btw
> servers at site B, without breaking the data integrity among the RO
> sites or affecting the atomicity of “vos release”.

AuriStorFS supports the desired functionality including the ability to
copy and move readonly sites between file servers or vice partitions
attached to the same file server.

  https://www.auristor.com/openafs/migrate-to-auristor/

OpenAFS does not contain explicit functionality but it is possible using

  vos dump
  vos restore -id -readonly
  vos addsite -valid

to achieve similar results.  From the source server use "vos dump" to
generate a dump stream of the readonly volume you wish to replicate.
Pipe the output to "vos restore" specifying the destination server,
partition, the readonly volume id and the -readonly flag to specify the
volume type.  Finally, use "vos addsite" with the -valid flag to update
the location service entry for the volume.  The -valid flag indicates
that the readonly volume data is known to be present and consistent with
other sites.  Note that the -valid switch will not mark a site as "new"
if a "vos release" failed to update one or more sites.

Be careful to use publicly visible addresses when executing these commands.

Jeffrey Altman

<<attachment: jaltman.vcf>>

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature

Reply via email to