Mainframes don’t de-dupe: Shoden shows ’em how it’s done

Written By: Peter Williams
Published:
Content Copyright © 2008 Bloor. All Rights Reserved.

De-duplication of
data during backup to save backup space is now common in the distributed and
open systems market. It can yield upwards of 95% backup disk space savings and
drastically alter the economics calculation related to using tape or disk for
archiving. Yet de-dupe has largely by-passed the mainframe world so far.

There are some
technical reasons for this to do with the complex way in which mainframes store
the different data types; yet, if these are overcome, huge storage savings are
there to be had. It means a smaller storage footprint, lower running costs,
less energy and cooling and, when data is transmitted to remote sites, a huge
saving on WAN transmission bandwidth and time. These factors help make de-dupe
attractive in these tough economic times.

Meanwhile, the
mainframe world is particularly wedded to tape for backup and archive; that
tends to mean long recovery times, whereas de-dupe solutions that write to disk
can be recovered much faster.

I mention this
because z/OS mainframe users in one country, South Africa, are already using a
de-dupe solution successfully. The company that supplies it—Shoden Data
Systems—is now launching in the UK through a subsidiary.

A major retailer
with z/OS mainframes, Edcon (South
Africa’s nearest equivalent to M&S with
a $3bn turnover), has so far achieved an 11:1 (91%) space-saving using Shoden’s
solution (which incorporates Data Domain’s market-leading de-dupe appliance).
It has also eliminated tape altogether and uses de-duped data transmission to a
remote site as part of its disaster recovery (DR) plan.

According to
Shoden Data Systems UK’s CEO John Taffinder, Edcon also achieves much lower
maintenance costs, achieves simplified and faster restores, and has re-deployed
tape staff.

“There is a
problem with tape [on mainframes] but people don’t want to spend,” said
Taffinder. “It is typical to take 3–5 hours to recover and most say they are
happy with 24 hour recovery (which in practice means two days to get back to
normal).” This problem is of course greatest if tapes need to be physically
retrieved from offsite stores.

He added that data
migration was much easier with disk, tape libraries were expensive to maintain
and disk reliability was higher. I also concur with him that de-dupe should be
attractive to mainframers everywhere. Right now, Shoden’s solution seems to be
the only one out there; so its short-term success may boil down to the market’s
perception of the economic value.

Edcon avoided
purchasing a new tape robot or smaller virtual tape library (VTL) to replace
their now unsupportable IBM tape robot; it found the Shoden solution worked out
more economical in addition to gaining all the added benefits just described. South Africa is not UK of course but similar ROI
calculations can be made here.

How the Shoden
solution works is conceptually simple and largely transparent to mainframe
operation. ‘QuickRecover’ uses Luminex VTL engine(s) to
translate the processed data from the mainframe as though going to an IBM 3940
tape drive—taking the processing load away from the mainframe. It uses fibre
channel (6-8 FICONs) and allows 1-2 ESCON or FICON tape emulations in changing
the data into a format that the Data Domain de-dupe NAS appliance can handle;
the output is then captured on an Intel Xeon-based Hitachi blade server (not otherwise available in the UK).

This process is
managed through Shoden’s own mainframe management GUI console using a
management server sitting within the VTL engine. This handles sizing and
configurability, recovery management, error logging and dashboard statistics
such as de-dupe ratios, performance and pain points. Flexibility is built in
so, for instance, it can be arranged as one data set per “tape cartridge”.

Shoden in the UK
is also able to take immediate advantage of the group’s well-established
and English-speaking 24×7 first-line support service from South Africa. So while
the UK
mainframe market is not huge, start-up teething troubles ought to be minimised.
Mainframe users seeking to cut costs quickly would do worse than take a close
look at how Shoden does it.