Wow, that's interesting!
I'll set up some tests myself. Thanks!
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
William Colwell
Sent: Wednesday, June 08, 2005 5:59 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Splitting files across tapes
Hi Wanda,
I have some real data which might mean something for your question. I
am in
the process of moving all the files on one server into collocation
groups.
I am copying tapes to sequential disk to do this. The sizes of full
disk
volumes vary a lot which might mean that an aggregate won't go across
disk
base sequential volumes. The data, see the Est. cap for the full
volumes --
tsm: XXX>q vol stg=seqdisk2
Volume Name Storage Device Estimated
Pct Volume
Pool Name Class Name Capacity
Util Status
------------------------ ----------- ---------- ---------
----- --------
/seqdisk2/cgseq2_000 SEQDISK2 SEQDISK2 2,016.0
100.0 Full
/seqdisk2/cgseq2_001 SEQDISK2 SEQDISK2 2,037.0
100.0 Full
/seqdisk2/cgseq2_002 SEQDISK2 SEQDISK2 2,016.9
100.0 Full
/seqdisk2/cgseq2_003 SEQDISK2 SEQDISK2 2,036.7
100.0 Full
/seqdisk2/cgseq2_004 SEQDISK2 SEQDISK2 2,043.4
100.0 Full
/seqdisk2/cgseq2_005 SEQDISK2 SEQDISK2 2,045.1
100.0 Full
/seqdisk2/cgseq2_006 SEQDISK2 SEQDISK2 2,035.0
100.0 Full
/seqdisk2/cgseq2_007 SEQDISK2 SEQDISK2 2,042.4
100.0 Full
/seqdisk2/cgseq2_008 SEQDISK2 SEQDISK2 2,008.0
100.0 Full
/seqdisk2/cgseq2_009 SEQDISK2 SEQDISK2 2,041.1
100.0 Full
/seqdisk2/cgseq2_00A SEQDISK2 SEQDISK2 2,034.3
100.0 Full
/seqdisk2/cgseq2_00B SEQDISK2 SEQDISK2 2,048.0
6.8 Filling
/seqdisk2/cgseq2_00C SEQDISK2 SEQDISK2 2,048.0
0.0 Empty
/seqdisk2/cgseq2_00D SEQDISK2 SEQDISK2 2,048.0
0.0 Empty
/seqdisk2/cgseq2_01F SEQDISK2 SEQDISK2 2,048.0
0.0 Empty
/seqdisk2/cgseq2_020 SEQDISK2 SEQDISK2 2,024.7
100.0 Full
Hope this helps,
Bill Colwell
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]
> On Behalf Of Prather, Wanda
> Sent: Tuesday, June 07, 2005 10:07 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Splitting files across tapes
>
> Hi Richard,
>
> Thanks for responding; maybe this will give you something to
> amuse your
> brain over morning coffee.
>
> The reason for the question, mgmt here is considering going
> to all-disk
> backup (for onsite).
> So our sequential "volumes" will be disk instead of tape.
>
> We occasionally have issues with mis-classified data ending up on a
> tape, and the tape has to be pulled and destroyed.
> No big deal with a tape. Big deal when the "volume" is a 1 TB raid
> array!
>
> So the question comes, what is the likelihood that we would
> contaminate
> TWO 1 TB raid arrays with a split file?
>
> I think for sequential volumes, TSM doesn't know that the volume is
> full, until it tries to write to it.
> If there isn't space for the next "block", then it mounts a
> scratch and
> rewrites the block to a new tape, yes?
>
> So can I assume that the file would have to be larger than an
> aggregate
> (what is that, MOVESIZETHRESH?) in order to end up split
> across 2 tapes?
>
> Thanks for lending brain power!
>
> W
>
>
>
>
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]
> On Behalf Of
> Richard Sims
> Sent: Tuesday, June 07, 2005 9:55 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Splitting files across tapes
>
>
> Hi, Wanda -
>
> I don't believe there is any rule, per se: it is just the case that
> the drive finally reaches end-of-volume (EOV - TSM msg ANR8341I).
> This results in the subsequent data being written in a spanned
> Segment on a new volume.
>
> Richard Sims
>
> On Jun 7, 2005, at 9:36 AM, Prather, Wanda wrote:
>
> > Does anyone happen to know what rules TSM uses to decide when to
> > split a
> > backup file/aggregate across 2 tapes?
> > Or can you point me to a document?
> >
> > (Management wants to know.)
> >
|
