ADSM-L

Re: [ADSM-L] NBU user considering switch to TSM

2008-09-30 09:44:17
Subject: Re: [ADSM-L] NBU user considering switch to TSM
From: Howard Coles <Howard.Coles AT ARDENTHEALTH DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Tue, 30 Sep 2008 08:42:07 -0500
See my response added to the many others below.

See Ya'
Howard


> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf
> Of steve sorenson
> Sent: Monday, September 29, 2008 4:58 PM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: [ADSM-L] NBU user considering switch to TSM
> 
> Hello all.  I'm a long-time user of NBU, but have recently started to
> consider switching our backups over to TSM.  My coworker used TSM at a
> previous company, but his experience was not as good as a friend of
> mine who
> speaks very highly of TSM.  I have a basic understanding of TSM's
> architecture, having perused some of the redbooks and poked around a
> bit in
> this list's archives (I understand progressive incrementals,
file-level
> version-tracking, expiration, reclamation, collocation, etc), but my
> coworker had some issues that I'm hoping have either been addressed or
> were
> user errors on his part.  I'm familiar with TSM's advantages, and NBU
> has
> its own list of issues to be sure, but I need to verify/debunk some of
> the
> perceived TSM disadvantages before we call in a sales rep.  I thought
> that
> this listserv would be a perfect place to get the straight scoop.
> 
> First, some clarification of good things I've heard about.  Is my
> interpretation correct?
> 
> 1. TSM will be migrating to a full DB2 database (if so, I think it
> would be
> the only one to use such a full-featured database for backups).  When
> will
> that happen?
> 
> 2. TSM will be doing deduplication in the TSM server (after data has
> been
> sent to the server).  Is this feature going to only apply to disk
> pools, or
> will it dedupe tape as well?  When is this supposed to happen?
> 
> 3. What interesting features have arrived since 5.3 (e.g. active
> datapools),
> and what interesting features are expected in the next release?
> 
> 4. Can anyone who has switched from NBU to TSM tell me of any
> advantages of
> TDP & TSM's NDMP over NBU's approaches to that?
> 
> Now for the concerns my coworker has:
> 
> 1. He could make simultaneous copies during the initial backup, but
not
> during migration and while copying to the copy pool.

Right, this is just a basic misunderstanding of the structure.  You can
do certain commands in serial, such as backup to a copy pool while
migrating to a primary tape pool, but you have to start them at the same
time, you can't start certain processes after starting others and have
them work very well.  However, I have had migration happening while
backing up to a copypool, while a client was trying to fill up the disk
pool and TSM handled it just fine.
 
> 2. Image backup (for a drive with millions of files) didn't support
> file-level restore.

Correct, out of nature.  You can do a file backup, and there are ways to
get around the millions of files problem, and an image backup together
for a full featured DR.  I don't do image backups as a rule, as I've
just never found a need for them if the backups are done certain ways.
In the case of a machine with millions of files, I would set that box up
for collocation, so that those millions of files are all in one place.

> 3. All migration/reclamation activities had to be done on the TSM
> server
> (the LAN-free storage agents couldn't help)

Correct, and there's no reason for them to.  Why would you want the
client to be worried about that?  The server is the box that you want
handling the data once its handed off so that the client can go about
its main purpose.  TSM, not the client, tracks and stores the data
according to the Policies you have defined so it, not the client, would
be best equipped to handle the movement of data from one storage pool to
the next.

> 4. Upgrading TSM clients to the latest version had to be done manually
> at at
> client.

Well, not necessarily, it depends on the method of application pushing
and installation.  You can do silent installs, and upgrades depending on
which version you are coming from and which version you are going to.
Some options are different for various versions and so some questions
have to be answered at the client.  Even then, I believe an answer file
can be used, I'd have to search on that.

> 5. You couldn't restore from a backup set using typical TSM
GUI/command
> (they are designed for use outside of TSM)

Not sure here what you mean.  You use the TSM GUI and/or command line to
do all the restores whether it be a backup set, or a backup from the TSM
server.

> 6. Adaptive subfile backup would require multiple tapes to restore a
> single
> file, as parts of the file would be spread out across tapes.

Possibly, yes depending on what storage pool the data is put into.

> Thanks in advance for your help.  Please be kind as TSM is not my
> native
> language. :)

TSM can give a lot of folks that glassy eyed look when all of its
features are exposed, and how it handles data is discussed.   However,
once they get it, they never quite have the same appreciation for
anything else.

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