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/[EMAIL PROTECTED] Internet e-mail: [EMAIL PROTECTED] 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 <[EMAIL PROTECTED]> Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> 02/18/2004 02:06 Please respond to "ADSM: Dist Stor Manager" To [EMAIL PROTECTED] 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 | | | <[EMAIL PROTECTED]| | | COM> | | | Gesendet von: | | | "ADSM: Dist Stor| | | Manager" | | | <[EMAIL PROTECTED]| | | T.EDU> | | | | | | | | | 17.02.2004 16:41| | | Bitte antworten | | | an "ADSM: Dist | | | Stor Manager" | |---------+---------------------------> >---------------------------------------------------------------------------------------------------------------------------------------------| | | | An: [EMAIL PROTECTED] | | 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:[EMAIL PROTECTED] Verzonden: dinsdag 17 februari 2004 16:03 Aan: [EMAIL PROTECTED] 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 | | | <[EMAIL PROTECTED]| | | COM> | | | Gesendet von: | | | "ADSM: Dist Stor| | | Manager" | | | <[EMAIL PROTECTED]| | | T.EDU> | | | | | | | | | 17.02.2004 10:49| | | Bitte antworten | | | an "ADSM: Dist | | | Stor Manager" | |---------+---------------------------> > --------------------------------------------------------------------------- ------------------------------------------------------------------| | | | An: [EMAIL PROTECTED] | | 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:[EMAIL PROTECTED] Verzonden: dinsdag 17 februari 2004 9:42 Aan: [EMAIL PROTECTED] 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:[EMAIL PROTECTED] http://www.emprise.de/enc Ein Unternehmen der EMPRISE Gruppe Diese e-Mail einschlie_lich ihrer Anhdnge ist vertraulich. Wir bitten, eine fehlgeleitete e-Mail unverz|glich vollstdndig zu lvschen und uns eine Nachricht zukommen zu lassen. Wir haben die e-Mail beim Ausgang auf Viren gepr|ft; wir raten jedoch wegen der Gefahr auf den \bertragungswegen zu einer Eingangskontrolle. Eine Haftung f|r Virenfreiheit schlie_en wir aus. This e-mail and any attachments are confidential. If you are not the intended recipient of this e-mail, please immediately delete its contents and notify us. This e-mail was checked for virus contamination before being sent. Nevertheless, it is advisable to check for any contamination occurring during transmission. 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