Question on HSM TSM.
All, In an environment where you are using HSM to manage disks (say for example Windows drives) after a period of time the file will be migrated to a storage pool within TSM and a stub file is left on the filesystem as a marker. I'm assuming that when this migration happens the TSM backup/archive client identifies the change and only backs up the stub - or does it need to recall the file from HSM and then back it up? If it does only backup the stub the issue is that you do not have a copy of a real file only a stub and no data. Can someone give me an idea as to how they have this type of scenario implemented within their environment? kind regards, Rowan.
Re: Question on HSM TSM.
On Oct 19, 2004, at 6:58 AM, Rowan O'Donoghue wrote: In an environment where you are using HSM to manage disks (say for example Windows drives) after a period of time the file will be migrated to a storage pool within TSM and a stub file is left on the filesystem as a marker. I'm assuming that when this migration happens the TSM backup/archive client identifies the change and only backs up the stub - or does it need to recall the file from HSM and then back it up? If it does only backup the stub the issue is that you do not have a copy of a real file only a stub and no data. Can someone give me an idea as to how they have this type of scenario implemented within their environment? Rowan - TSM never backs up HSM stub files, as that would be pointless. It backs up the file, either from the file system or directly from the HSM storage pool if migrated and using same server. See the (old) HSM redbook at http://www.redbooks.ibm.com/abstracts/sg244631.html which explains how it all works in different configurations, and advises on restoral methods. Richard Simshttp://people.bu.edu/rbs
Re: Question on HSM TSM.
Richard, Rowan This is a theoretical scenario only. If the file has been migrated, normally the reason is that it hasnt been updated, modified or accessed within a specified time limit. Therefore, TSM(with it's progressive incremental technology) would never need to backup the file(it hasnt changed). If you where to do a selective backup of all files TSM would retrieve them from HSM storage(or, the HSM software would be the one retrieving them as TSM are trying to access the files). This however isnt true for all HSM products. DX2000(OTG/Legato) can for example co-operate with TSM and only let TSM back up the stub files. There is no reason TSM would backup the HSM migrated files as migrated files normally havent changed. If you where to change an HSM migrated file, it would normally be recalled from HSM storage and therefore no longer be HSM managed. Mvh // Daniel --- Daniel Sparrman Chef Utveckling Drift Exist i Stockholm AB Propellervägen 6B 183 62 TÄBY Växel: 08 - 754 98 00 Mobil: 070 - 399 27 51 Richard Sims [EMAIL PROTECTED] Sent by: ADSM: Dist Stor Manager [EMAIL PROTECTED] 2004-10-19 13:17 Please respond to ADSM: Dist Stor Manager [EMAIL PROTECTED] To [EMAIL PROTECTED] cc Subject Re: Question on HSM TSM. On Oct 19, 2004, at 6:58 AM, Rowan O'Donoghue wrote: In an environment where you are using HSM to manage disks (say for example Windows drives) after a period of time the file will be migrated to a storage pool within TSM and a stub file is left on the filesystem as a marker. I'm assuming that when this migration happens the TSM backup/archive client identifies the change and only backs up the stub - or does it need to recall the file from HSM and then back it up? If it does only backup the stub the issue is that you do not have a copy of a real file only a stub and no data. Can someone give me an idea as to how they have this type of scenario implemented within their environment? Rowan - TSM never backs up HSM stub files, as that would be pointless. It backs up the file, either from the file system or directly from the HSM storage pool if migrated and using same server. See the (old) HSM redbook at http://www.redbooks.ibm.com/abstracts/sg244631.html which explains how it all works in different configurations, and advises on restoral methods. Richard Simshttp://people.bu.edu/rbs
Re: Question on HSM TSM.
On Oct 19, 2004, at 7:37 AM, Daniel Sparrman wrote: This is a theoretical scenario only. If the file has been migrated, normally the reason is that it hasnt been updated, modified or accessed within a specified time limit. Therefore, TSM(with it's progressive incremental technology) would never need to backup the file(it hasnt changed). ... The primary criterion for TSM backing up a file is whether it yet exists within TSM backup pool storage: if TSM does not yet have it, it wants it in its collection. So, expect a backup, in standard Incremental processing. Whether the file in the HSM-controlled file system migrates is also a control item: the MIGREQUIRESBkup management class parameter governs this. Richard Sims
Re: Question on HSM TSM.
Richard, I agree with what you say, and it is pointless in restoring the file to the original filesystem just to back up that file if it is already migrated to tape. I see that there is an option with DiskXtender to do a backup of the file to TSM before it is migrated to tape and any subsequent backups of the file can be ignored if the file size is zero Still reading ;) kind regards, Rowan O'Donoghue Technical Services Manager Unitech Systems Unit 2, First Floor, Bracken Court, Sandyford Industrial Estate, Dublin 18. DDI: + 353 - 1 - 2999357 Tel: + 353 - 1 - 2942300 Fax: + 353 - 1 - 2942319 www.unitech-ie.com |-+---| | Richard Sims [EMAIL PROTECTED] | | | Sent by: ADSM: Dist Stor | | | Manager | To| | [EMAIL PROTECTED]| [EMAIL PROTECTED]| | | M.MARIST| | 19/10/2004 12:17 | .EDU| | | cc| | | | | Please respond to |Subject| | ADSM: Dist Stor| Re: | | Manager| Question| | [EMAIL PROTECTED] | on HSM | | | TSM.| | | | | | | | | | | | | | | | | | | |-+---| On Oct 19, 2004, at 6:58 AM, Rowan O'Donoghue wrote: In an environment where you are using HSM to manage disks (say for example Windows drives) after a period of time the file will be migrated to a storage pool within TSM and a stub file is left on the filesystem as a marker. I'm assuming that when this migration happens the TSM backup/archive client identifies the change and only backs up the stub - or does it need to recall the file from HSM and then back it up? If it does only backup the stub the issue is that you do not have a copy of a real file only a stub and no data. Can someone give me an idea as to how they have this type of scenario implemented within their environment? Rowan - TSM never backs up HSM stub files, as that would be pointless. It backs up the file, either from the file system or directly from the HSM storage pool if migrated and using same server. See the (old) HSM redbook at http://www.redbooks.ibm.com/abstracts/sg244631.html which explains how it all works in different configurations, and advises on restoral methods. Richard Sims http://people.bu.edu/rbs ForwardSourceID:NT00015B9E
