Tom,
thanks for your input. I agree with you if our banks have the requirement
to be online again after 1 day they will need a faster network,
or a other backup solution.
And here is, in my opinion, the point where IBM has to chenge something. If
ADSM
won't be able to provide a easy seconf king of recover technique we really have
to change.
I really like ADSM and his concept, but here is a leak. Most of our banks use
ADSM to protect
the client workstaions AND 1 to 5 servers. If the gap between disk size and
network-speed
becomes bigger, we will have to find other backup solution with direct
connection to the servers.
Stephan
Stephan,
You've gotten several good suggestions about how you might
approach this, but I'd like to offer a comment on something you
mentioned in the message below, namely, that "[f]or [the banks']
size, the ring speed is enough." Although this may be the case
for their day-to-day operations, if the banks have identified a
requirement that restore times be less than 20 hours, either the
network speed is *not* if they are wanting to use a network
backup solution, or a completely different backup solution is
necessary.
Not having any experience with Token Ring, I'll take your word
for it that it would take 20 hours, but based on my math, even if
you only got an effective bandwidth of 8Mb/s, you could still
push that amount of data in about five hours.
I think many others on this list would concur with me when I say
that 18GB is a decidedly small file server in this day and age.
We have workstations in our environment with that amount of disk
space, and our file servers run to TBs.
-- Tom
On Fri, 12 Mar 1999, Stephan Rittmann wrote:
>
Hi Eric,
>
>yes you're right, but we have no other choice. We are a service
>provider for banks and these banks all have a 16Mb TR. For their
>size (10 to 50 workstations) the ring speed is enough.
>In the past these companies had 6 fileservers with approx. 2 to4
>GB disks. Now the disks become bigger and bigger and they have
>only one server with 18 GB. The ring speed as really enough
>for such an installation. I can understand that they don't want
>to spend money for a faster network. The problem is that we now
>have the same amount of data on less physical servers.
>I think that we need a second kind of restore ability with ADSM.
>
>Im looking forward to other suggestions or opinions.
>
>Bye,
>Stephan Rittmann
>
>
>
>
>Hi Stephan!
>Restoring 18 Gb. trough Token Ring is not a good idea. Your company should
>think about a separate backup network. We are currently thinking about it,
>based on 1Gb. Ethernet.
>Kindest regards,
>Eric van Loon
>
>-----Original Message-----
>From: Stephan Rittmann [mailto:srittmann AT FIDUCIA DOT DE]
>Sent: Friday, March 12, 1999 13:59
>To: ADSM-L AT VM.MARIST DOT EDU
>Subject: ADSM and big file-servers
>
>
>
>Hi all,
>
>I want to start a discussion about ADSM and backing up big file servers. In
>our
>environment we have 16 Mbit token-ring networks and we are using ADSM to
>back
>up all of the critical data.
>The biggest file servers that we use at the moment has a 18 GB data
>partition.
>Backing up these servers with incremental backup is no problem. It works for
>a
>long time, everybody is satisfied about the short backup times. But what
>will
>happen in the case of a disk failure. If the server was very full, you have
>to
>restore up to 18 GB. With our kind of netwotk this would take about 20
>houres
>or more.
>What I want to say is; The disks in the servers become bigger and bigger,
>the
>backup time is still the same because of the incremental technique from
>ADSM.
>I'm sure that most of the useres from ADSM don't think about the long
>restore
>times in case of a disk failure.
>The difference between the network speed and the size of the data disks
>becomes
>bigger and I see a problem in this fact.
>
>What are you think about these? And how could we solve these problem?
>
>Stephan Rittmann
>FIDUCIA AG, Karlsruhe
>Germany
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