First off, thank you for your kind words, really appreciate that.
One thing to note some recent announcements regarding DLm and PowerMax
from Dell. Like IBM we now have Transparent Cloud Tiering (TCT), between the
PowerMax and DLm. Like IBM we require our DASD and Virtual Tape product for
this to work. One of the differences in this solution is that the connectivity
between the PowerMax and DLm is we use FICON to move the data between the two
systems.
Also, for quite awhile now the DLm has had the ability to move
(migrate) data from its data storage to another tier of storage (Cloud). This
feature is referred to as Long Term Retention the DLm will move the data to and
from the storage without any need for host cycles. Generally, we see customers
looking at this feature for data that does not have high access patterns,
generally like archive data or data that have not been accessed for a long
period of time. The user can create the policy (usually last time the tape was
mounted) that best meets their needs and the DLm will move that tape once the
policy is meet. If the tape is needed the DLm will access the new location
directly and the data will flow back to the mainframe. We do not recommend
using this feature for data or tapes that have a high frequency of recall.
As to the tape management functions, we are different being a MTL. What
will take place is a step will be added to the house keeping routine that will
pass the daily or full scratch list to the DLm. It is that process that will
then mark the tape as a scratch tape in the DLm.
Carl Swanson
Mobile:215.688.1459
Email: [email protected]
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of
Michael Watkins
Sent: Thursday, March 4, 2021 11:25 AM
To: [email protected]
Subject: Re: EMC DLM over IBM VTL
"Will there be a impact to mainframe backup when there is a high backup volume
for open system ?"
I am employed by the Texas CPA where such a solution was implemented. We never
experienced any problems with contention. First, our z/OS mainframe necessarily
had its own MTree file structure on the Data Domain, so there was no contention
at the file level. The mainframe activity at this installation is characterized
by a couple of bursts of activity each week while the open systems activity is
more distributed through out the week, so the performance of the Data Domain
has never been challenged.
NB: The DLm emulates a manual tape library. An IBM TS7000 is an automatic
library.
NB: The TS7000 is capable of communicating directly with an IBM DS8000-class
storage frame. The DLm is not.
Two caveats: (1) The TS7000 communicates with z/OS tape management software.
The DLm does not. This complicates tape management. (2) If you are
contemplating the achival of mainframe data on cloud storage using IBM's Cloud
Tape Connector (CTC) solution, the DLm will not be able to do this. It will
also complicate implementation of IBM's Transparent Cloud Tiering (TCT).
I don't believe you can find someone more knowledgeable about of Data
Domain/DLm implementations than Carl Swanson.
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of
Carl Swanson
Sent: Thursday, March 4, 2021 8:18 AM
To: [email protected]
Subject: Re: EMC DLM over IBM VTL
CAUTION: This email originated from outside of the Texas Comptroller's email
system.
DO NOT click links or open attachments unless you expect them from the sender
and know the content is safe.
First full disclosure I work for Dell Technologies but more
specifically in the DLm group, now with that out of the way.
Probably more than 50% of the DLm customers do share their backend
(Data Domain) storage with the distributed world and or the IBM-I world. What
this means is we have experiences in sizing these types of solutions. When we
perform this sizing, we will do a study on the mainframe the distributed side
and the IBM I if required. We then make sure that the performance
characteristics of the back end storage array is capable of handling the peak
workload without issue. From the DLm point of view this is the connection to
the mainframe and we size the performance requirements based on the supplied
RMF data .
I can provide much more detail if you like just not sure if it is
appropriate to do so on list. Below is my non work email, but most could
probably figure out my work email.
Final answer this is a common for DLm systems and works great the key
is proper sizing which my group handles.
Carl Swanson
Mobile:215.688.1459
Email: [email protected]
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of
Jake Anderson
Sent: Thursday, March 4, 2021 1:16 AM
To: [email protected]
Subject: EMC DLM over IBM VTL
Hello
We are analysing if EMC DLM would be a right fit to replace IBM VTL.
I am trying to understand about backup cycles using EMC DLM when we use single
backup solution and single virtual tape library to backup both mainframe and
open systems.
Is there a possibility for contention ?
Will there be a impact to mainframe backup when there is a high backup volume
for open system ?
These performance do effect the open system as well ?
Trying to understand these from the DLM users ? Any feedback would be
appreciated
Jake.
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