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Home > Archive > Data Storage > May 2004 > Re: TSM storage used?
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Re: TSM storage used?
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| Dan Foster 2004-05-30, 11:10 am |
| In article <107nrh5co8esu4f@corp.supernews.com>, Mike <mikee@mikee.ath.cx> wrote:
> How can I query TSM to find how much storage is currently in use
> now (tape) for all the files (corporate-wide) that are backed
> up (under TSM's control)? I was just asked a question do we
Run the dsmadmc utility (TSM administrative tool) and do a 'query
stgpool' (or 'q stg' for short) and add up numbers.
> want to get rid of the tape robot and move to JBOD instead.
> Thoughts on doing that kind of move?
Not bad if you want to optimize for faster restores but rather poor for
archiving... and one generally probably wants to still have tape backups
to back up disk data. Put it another way: would you have faith in
reliance of hard drives to save the organization when a bad day hits?
I've got a pile of 20 dead drives by my desk -- and I would say no. 
(My boss has the other pile of ~25.)
Put it another way... how often do you do restores? (some sites do it
all the time) Is it a time critical environment like a bank, hospital,
nuclear plant, and so forth where data must be available in milliseconds
instead of ~1-3 minutes? That setup is why a lot of Wall St. firms
bought disk based setups *but* they also had tape backing it up.
Basically as a multi-tiered strategy; disk for rapid backups/restores
but if disks goes south, replace disk, and restore data to disk from
tape, making data easily available again. (Or even pulling directly from
tape until failed disk is replaced.)
TSM can accommodate the above scenario trivially, and that's what I
would go if I had a need to put in disks as primary restore media.
Our tape libs are fast enough and our restores so far and few between
(and usually for a single file or directory) that we haven't needed this
so far.
We also use a diskpool as an intermediate staging area to accelerate
backups and get maximum client->server->disk->tape performance. So we
actually do get most of the benefits of using disks, albeit not for
restores... but frankly, not really an issue because the tape drive runs
at speeds well exceeding Fast Ethernet... about 2.5x faster.
I can see how it'd be more of an issue with older drives that can't
saturate the network, though. A properly designed LTO-2 setup can also
fill a gig-e pipe at full tape speed and actually ship data around at
least as fast as drives or even faster (albeit waiting 1-3 minute to
start peeling data off tape vs waiting 4.5ms), too.
-Dan
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| Jan-Frode Myklebust 2004-05-30, 11:10 am |
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In article <slrnc7nt7o.rab.usenet@gaia.roc2.gblx.net>, Dan Foster wrote:
>
> Not bad if you want to optimize for faster restores but rather poor for
> archiving... and one generally probably wants to still have tape backups
> to back up disk data. Put it another way: would you have faith in
> reliance of hard drives to save the organization when a bad day hits?
I would have about the same faith in hard drives as tapes. With TSM I would
want to use separate copy pools on separate disks and controlers (and servers?)
in case of disk failures, just as we do with tapes.
Actually I think you can do even better with copy pools on disk arrays with
RAID5, than what's possible with tape.
Only advantages tapes still has is that they generate less heat, and still
seems to be quite a bit cheaper than disks.
-jf
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| Faeandar 2004-05-30, 11:10 am |
| On 13 Apr 2004 16:35:20 GMT, Jan-Frode Myklebust
<janfrode@parallab.uib.no> wrote:
>
>In article <slrnc7nt7o.rab.usenet@gaia.roc2.gblx.net>, Dan Foster wrote:
>
>I would have about the same faith in hard drives as tapes. With TSM I would
>want to use separate copy pools on separate disks and controlers (and servers?)
>in case of disk failures, just as we do with tapes.
>
>Actually I think you can do even better with copy pools on disk arrays with
>RAID5, than what's possible with tape.
>
>Only advantages tapes still has is that they generate less heat, and still
>seems to be quite a bit cheaper than disks.
>
> -jf
Also more easily portable. But I agree with the faith in disk v.
tape. You lose one disk and you can recover, you lose one tape and
you may be horked but good.
~F
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| acebgur 2004-05-30, 11:11 am |
| Mike <mikee@mikee.ath.cx> wrote in message news:<107nrh5co8esu4f@corp.supernews.com>...
>
> I was just asked a question do we want to get rid of the tape robot
> and move to JBOD instead. Thoughts on doing that kind of move?
>
Don't forget...the most recent release of TSM (V5.2.2) also supports a
native Centera integration.
http://www-306.ibm.com/software/tiv...ments-v5.2.html
Rob Y...That would be 101 ;-)
Best of luck!
Ace
http://groups.yahoo.com/group/CenteraTechGroup/
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| Malcolm Weir 2004-05-30, 11:11 am |
| On 22 Apr 2004 15:25:10 -0700, acebgur@yahoo.com (acebgur) wrote:
>Mike <mikee@mikee.ath.cx> wrote in message news:<107nrh5co8esu4f@corp.supernews.com>...
>
>Don't forget...the most recent release of TSM (V5.2.2) also supports a
>native Centera integration.
Why would anyone care?
You are increasingly sounding like a desperate marketroid...
If you have nothing to say to Mike, try keeping your metaphorical
mouth shut...
Malc.
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| In article <odig80lhtcqlj7e5poha45a6bdkcu4eg84@4ax.com>, malc@gelt.org
says...
> On 22 Apr 2004 15:25:10 -0700, acebgur@yahoo.com (acebgur) wrote:
>
>
> Why would anyone care?
>
> You are increasingly sounding like a desperate marketroid...
>
> If you have nothing to say to Mike, try keeping your metaphorical
> mouth shut...
>
> Malc.
>
Hey Malcolm. Go easy on our friend here. If all you have is a hammer,
the whole world starts looking like a nail...
--paul
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| Rob Young 2004-05-30, 11:11 am |
| In article <43292cf8.0404221425.1cc044eb@posting.google.com>, acebgur@yahoo.com (acebgur) writes:
> Mike <mikee@mikee.ath.cx> wrote in message news:<107nrh5co8esu4f@corp.supernews.com>...
>
> Don't forget...the most recent release of TSM (V5.2.2) also supports a
> native Centera integration.
>
> http://www-306.ibm.com/software/tiv...ments-v5.2.html
>
> Rob Y...That would be 101 ;-)
>
> Ace
>
Hey Ace - I'll do you one better. 5.2 supports virtual tapes.
So for D2D backups you would of course use a much cheaper
solution (i.e. FastT and SATA) instead of Centera.
Rob
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