The README is perhaps a little misleading in this regard, as it does not
entirely explain how the snapshot backup works. In fact, when using open
file support, the entire volume is backed up via the snapshot method, not
just open files. The idea is to capture the entire volume at a moment in
time (hence the term "snapshot", like a photograph taken with a camera
captures a moment in time). So while the backup is running, disk writes
are intercepted by the LVSA, held until the LVSA can copy the original
data (at the block level) to the snapshot cache, then allowed to go
through. When it is time for TSM to back up the changed file, TSM backs up
the original data from the snapshot cache, not the changed data.
While I am not familiar with the performance characteristics of open file
support, this does incur some additional overhead which will vary with the
amount of data being changed during the course of the backup. What kind of
performance characteristics to you see?
Regards,
Andy
Andy Raibeck
IBM Software Group
Tivoli Storage Manager Client Development
Internal Notes e-mail: Andrew Raibeck/Tucson/IBM@IBMUS
Internet e-mail: storman AT us.ibm DOT com
The only dumb question is the one that goes unasked.
The command line is your friend.
"Good enough" is the enemy of excellence.
Karin Dambacher <karin.dambacher AT EMPRISE DOT DE>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
02/18/2004 02:06
Please respond to
"ADSM: Dist Stor Manager"
To
ADSM-L AT VM.MARIST DOT EDU
cc
Subject
Antwort: Re: Antwort: Re: Open File Support
Hi,
yes I know the readme, but I I have tested it with closed files, and
backup
is more slow. And if there is no option snapshotcachelocation in dsm.opt I
will get message ANS1327E which says, that he can not backup the file with
a snapshot, but why does he want to do it, the file is not open or locked.
Best regards, Karin
|---------+--------------------------->
| | Karel Bos |
| | <Karel.Bos@NUON.|
| | COM> |
| | Gesendet von: |
| | "ADSM: Dist Stor|
| | Manager" |
| | <[email protected]|
| | T.EDU> |
| | |
| | |
| | 17.02.2004 16:41|
| | Bitte antworten |
| | an "ADSM: Dist |
| | Stor Manager" |
|---------+--------------------------->
>---------------------------------------------------------------------------------------------------------------------------------------------|
| |
| An: ADSM-L AT VM.MARIST DOT EDU |
| Kopie: (Blindkopie: Karin Dambacher/Emprise) |
| Thema: Re: Antwort: Re: Open File Support |
>---------------------------------------------------------------------------------------------------------------------------------------------|
Hi,
This is from the readme.
Open file support for backup and archive operations on Windows 2000 and
Windows XP
If the Logical Volume Snapshot Agent (LVSA) is installed and configured
for
open file support via the setup wizard, by default, Tivoli Storage Manager
performs a snapshot backup or archive of files that are open (or locked)
by
other applications. The snapshot allows the backup or archive to be taken
from a point-in-time copy that matches the file system at the time the
snapshot is taken. Subsequent changes to the file system are not included
in
the backup or archive operation. You can use the include.fs option to
specify whether a drive uses open file support. See Open file support for
backup operations (Windows 2000, XP) and Open file support for archive
operations (Windows 2000, XP) for more information.
Note that it says only open or locked files are handeld, so theirs no way
this will slow down the back-up of non open files.
Regard,
Karel
-----Oorspronkelijk bericht-----
Van: Karin Dambacher [mailto:karin.dambacher AT EMPRISE DOT DE]
Verzonden: dinsdag 17 februari 2004 16:03
Aan: ADSM-L AT VM.MARIST DOT EDU
Onderwerp: Antwort: Re: Open File Support
Hi,
I think, if Open File Support is installed and a snapshotcachelocation is
defined, tsm-client will backup as well open files as not open files in
this cache-manner and backup will take more time, isn't it? If a
snapshotlocation is not defined and open file support is installed, backup
of not open files will cause a corresponding error message (ANS1327E). Or
is there a way for definition I do not know?
Best regards, Karin
|---------+--------------------------->
| | Karel Bos |
| | <Karel.Bos@NUON.|
| | COM> |
| | Gesendet von: |
| | "ADSM: Dist Stor|
| | Manager" |
| | <[email protected]|
| | T.EDU> |
| | |
| | |
| | 17.02.2004 10:49|
| | Bitte antworten |
| | an "ADSM: Dist |
| | Stor Manager" |
|---------+--------------------------->
>
---------------------------------------------------------------------------
------------------------------------------------------------------|
|
|
| An: ADSM-L AT VM.MARIST DOT EDU
|
| Kopie: (Blindkopie: Karin Dambacher/Emprise)
|
| Thema: Re: Open File Support
|
>
---------------------------------------------------------------------------
------------------------------------------------------------------|
Hi,
Because the back-up of both C: and D: are running at the same time, no
idle
filesystem is found. Workaround, create a small e: and make this for both
c:
and d: the cache. Why the system needs a hardware reset is strange. My
experience was a clear error and back-up was done as a normal incremental.
Regard,
Karel
-----Oorspronkelijk bericht-----
Van: Karin Dambacher [mailto:karin.dambacher AT EMPRISE DOT DE]
Verzonden: dinsdag 17 februari 2004 9:42
Aan: ADSM-L AT VM.MARIST DOT EDU
Onderwerp: Open File Support
Hi,
I have tried open file support with the following options in dsm.opt:
include.fs c: fileleveltype=snapshot snapshotcachelocation=d:\cache\
include.fs d: fileleveltype=snapshot snapshotcachelocation=c:\cache\
If I backup with the option "domain c: d:", the client is hanging
completely, only hardware reset helps.
If I backup first with "domain c:" and second time with "domain d", backup
works fine.
Backup works fine too with
domain c: d:
include.fs c: fileleveltype=snapshot snapshotcachelocation=e:\cache\
include.fs d: fileleveltype=snapshot snapshotcachelocation=e:\cache\
Why is the crossdefinition above not working?
Best regards, Karin Dambacher
EMPRISE Network Consulting GmbH
Albstra_e 14
D - 70597 Stuttgart
t_ +49 (0) 711 - 99 00 83 - 0
f_ +49 (0) 711 - 99 00 83 - 9
m_ +49 (0) 172 - 4033256
mailto:karin.dambacher AT emprise DOT de
http://www.emprise.de/enc
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