Hi, On Fri, 2010-03-26 at 02:48 +0000, Jankowski, Chris wrote: > Hi, > > Question: > --------- > Are there any plans to develop a backup utility working on the same > principles as dump(8) does for ext3fs? This means getting the backup done by > walking the block structure contained in the inodes instead of just reading > the file the way tar(1), cpio(1) and others do it. > Does dump use FIEMAP? If so it should "just work" on recent GFS2,
Steve. > I need dump(8) to deal with a specific problem created by the customer's > application. A library used by the application has a bug which demonstrates > itself in an upredictable creation of huge sparse files. For example the > application may create a sparse file of 5TB with only a few kB of data in it. > There may be tens of those files created in the database. GNU tar handles > sparse files correctly and will recreate them as sparse files too. This is > fine. But it still needs to read all of those nulls and that is done at a > rate of about 1.5TB per hour on this system. With 100+ TB of the apparent > size of all of those sparse filesmy bakup would take about 3 days to complete. > > By comparison, dump(8) would deal with this situation perfectly well. It know > the inodes of the file, will follow the few that exist in a sparse file and > back up the data. It does not have to read through the tons of nulls happily > delivered by the OS, as tar(1) does. > > Regards, > > Chris > > > > -- > Linux-cluster mailing list > [email protected] > https://www.redhat.com/mailman/listinfo/linux-cluster -- Linux-cluster mailing list [email protected] https://www.redhat.com/mailman/listinfo/linux-cluster
