Re: LAN and SAN backups. Don't expect that you can restore your b acku ps if you have a mixed LAN/SAN environment.
2003-05-13 14:20:51
Jan,
This doesn't sound right.
The DP for xxx clients should be able to restore the data
without having to do anything special.
Files which are inaccessible to the storage agent
are supposed to be restored, although there will be a performance hit.
These files are supposed to be proxy restored from the server to
the storage agent and from there back to the client (the data is moved
twice).
If you are not finding that to be the case,
please call IBM support.
Thanks,
Del
----------------------------------------------------
> Yes, the LAN path isn't used! Thus the restore will fail when the object
is
> on disk. Even worse is that in our case it failed in the end of a large
> restore after first having restored the online backups and in the end the
> transaction logs that unfortunately were on a disk pool.
>
> The following is part of the answer from IBM regarding this problem.
There
> is nothing in here about API/TDP but it gives you the idea about how
> development seems to see this problem (feature). Of course we do not
migrate
> to disk in our case but the outcome is the same:
>
> "Doc #1067224 - IBM Tivoli Storage Manager: Files not restorable in a
> LAN-Free environment
> Problem Desc: In a LAN-Free environment files that have migrated to
storage
> pools who's device classes are not SAN attached or accessible (such as
> devclass DISK) can become un-retrievable to your LAN-Free enabled client
> unless special actions are taken.
> Solution: Files that are stored in storage pools that are not SAN
attached
> or accessible have to be moved over the LAN path. In most cases the
> customer runs into a problem when attempting to restore a single active
file
> or and inactive copy of any number of files. The reason is that the
> customer is not performing a 'no query restore'. A no query restore is
> defined as any restore using an unrestricted wildcard source file
> specification, and not using any of the options: INACTIVE, PICK, FROMDATE
> or TODATE.
>
> For example: dsmc restore /home/myfiles/*
>
> A LAN-Free enabled client must use a 'non query restore' to enable a
duel
> session restore over LAN-Free. This duel session restore allows the
client
> to open more than one concurrent session. These 2 sessions allow the
client
> to retrieve data over the LAN-Free path and the LAN path on the same run.
> In cases where a 'no query restore' is not possible then you will need to
> retrieve files that are not LAN accessible by disabling 'enable lanfree'
> from your dsm.sys (dsm.opt in windows) file.
>
> Customers typically run into this problem for performance reasons. Small
> files do not transfer efficiently over LAN-Free connections due to the
meta
> data overhead. Thus they set up policy so that small files are moved
over
> the LAN to a DISK storage pool. In order to reduce this problems impact
TSM
> administrators should migrate these DISK storage pools to a LAN-Free
> accessible storage pool as soon as possible. "
>
> Jan
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