Hi, Le mercredi 03 février 2010 13:59:59, Pascal Vandeputte a écrit : > Dear Bacula developers, > > A few years ago I deployed IBM Tivoli Storage Manager in the company I > worked for at the time. Since then I've never really encountered a > backup product that could match it in terms of speed or resource > utilization, which can be entirely attributed to the "progressive > incremental" backup strategy it uses. A file is never transferred over > the network twice, TSM always takes incremental backups and keeps track > of files it already has somewhere in its backup pool by using a > relational database (IBM DB2 since TSM version 6). For a longer > explanation, see > > https://agora.cs.illinois.edu/display/tsg/Progressive+Incremental+Backups+e > xplained > > Only new files are transferred to backup storage, files which have > disappeared from the host since the previous backup are marked inactive > and eventually purged from backup storage depending on the defined > retention policies. It backs up to disk at night for speed, and > transfers from disk to tape during working hours in a FIFO manner. This > way restores are often almost instantaneous because the recent backup > data is still on disk. Other daytime tape maintenance operations involve > the creation of an off-site copy of the primary storage pool tapes > (which are always on-line (!), your tape library must be large enough to > accomodate this), reclamation (freeing tapes with mostly expired data) > and collocation (moving data from a specific host on as least tapes as > possible).
What you describe looks like our VirtualFull feature present in 3.0.0. You always run Incremental (accurate mode), and to speed up restore (and cleanup), you can merge backups (Full+Incr+Incr) into a new Full without client connection. See documentation for more details. > The system works really well. Unfortunately no other backup product that > I know of implements the same backup strategy. As a side effect, there > is no real competition in this space and the licensing costs of TSM > aren't pretty... My current employer isn't a TSM shop and as I'm not > exactly thrilled with our current backup solution, I'm looking at > affordable TSM alternatives but it appears that there just aren't any. Affordable TSM alternative? Doux euphémisme :) > I hoped that Bacula's new "basejob" deduplication feature would start > offering something in this direction (as files in a basejob are only > backed up once), but now that I've read a bit more about it, it doesn't > seem to do what I hoped for. :-( No, this is different. > What could be the reason no other companies or open source projects go > in this direction? We have something very similar to this feature. Bye > There are great open source databases, there are > great open source backup projects, but there are none which attempt to > forge these technologies into an "always incremental" backup product (or > "enterprise class data management system" as some prefer to call it...). > > Best regards, > > Pascal > > P.S. The following document is a great introduction to TSM concepts: > http://www.redbooks.ibm.com/redpapers/pdfs/redp0044.pdf > ------------------------------------------------------------------------------ The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com _______________________________________________ Bacula-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-devel
