---++ Official How-To [[http://trac.dcache.org/wiki/pnfsDump2MigratePnfs2Chimera][Official How-To]] ---++ Prepare Chimera We need a working pristine chimera installation in the target host. Chech ServiceDcache to know how to (everything but don't populate the VOs dirs). ---++ Obtain the dump file with all pnfs information For this you need to know the: * *pnfsid of the source dir*: In the source host look at =/pnfs/fs/admin/etc/config/serverRoot= and make sure it's the same as =cat /pnfs/fs/'.(id)(usr)'= * *pnfsid of the target dir*: In the target host perform =cat /mnt/pnfs/'.(id)(lcg.cscs.ch)'= Then we need to install the latest pnfs-dump rpm and perform in the source: <verbatim>time /opt/pnfs/tools/pnfsDump -r <pnfsid of the source dir> -vv -d0 -o chimera /tmp/pnfs.sql -2 -p <pnfsid of the target dir> -o verify /tmp/verify.md5 -r -o files /tmp/files.lst -f ###You can expect something like this: Final stats: inodes: nDir: 137024 nFile: 577029 nUnknown: 0 nSkipped: 0 ----------------- Total: 714053 Major DB errors: 0 Cache queries: 13101440 (hits: 6550720, misses: 0) Time elapsed: 395.9s (00:06:35.9) dbserver: 297.1s (00:04:57.1) overhead: 4.9s (00:00:04.9) pnfsDump: 93.9s (00:01:33.9) Average inode processing rate: 1808 Hz real 6m35.866s user 1m39.162s sys 0m30.455s </verbatim> And we copy them to the target host: <verbatim>scp /tmp/verify.md5 /tmp/pnfs.sql /tmp/files.lst root@storage22:</verbatim> And also an initialization SQL script from pnfs-dump RPM: <verbatim>scp /opt/pnfs/share/sql/prep-chimera-for-migration.sql root@storage22:</verbatim> ---++ Import pnfs dumps into Chimera * *First ensure chimera is unmounted and chimera-nfs service is shut down* * Prepare chimera for migration (with the script copied from last step) * Then dump the metadara and check the output file doesn't contain errors. * And finally start the service and mount chimera. Move around the filesystem, should look like the old pnfs. <verbatim>umount /mnt service chimera-nfs stop psql -U postgres -f /root/prep-chimera-for-migration.sql chimera time psql -U postgres -f /root/pnfs.sql chimera > pnfs.sql.injection.stdout service chimera-nfs start mount localhost:/ /mnt </verbatim> ---++ Check everything worked fine The first test is the MD5sum. In the Chimera node, with the filesystem mounted in /mnt as usual, perform <verbatim>cd /mnt/pnfs/lcg.cscs.ch/ time md5sum -c /root/verify.md5 | tee /root/verify.md5.result | grep -v :\ OK$</verbatim> The second check (StorageInfo) needs to run on the chimera node with chimera unmounted and pnfs mounted: <verbatim>umount /mnt mount #and check chimera is not mounted anywhere else service chimera-nfs stop mkdir -p /pnfs/fs cd /pnfs ln -s /pnfs/fs ftpBase ln -s fs/usr lcg.cscs.ch mount storage02.lcg.cscs.ch:/fs /pnfs/fs ## If you can't, probably need to add something to /pnfs/fs/admin/etc/exports pn the pnfs host time sh /opt/d-cache/libexec/migration-check.sh -k /root/files.lst 2> /root/files.lst.errors > /root/files.lst.stdout</verbatim> ---++ Timing You have to wait for certain commands to finish. This is an approximation of how much you can leave for a coffee (for almost 600k files): * Dump pnfs information: 7 minutes * Import metadata into chimera: 80 minutes * md5sum check: 75 minutes * StorageInfo check: 85 minutes ---++ Issues We've discovered during the procedure that some directories lack the RetentionPolicy and AccessLatency tags that their parents have. This is the list: <verbatim>hone/ppraxmar-srmmkdir-test-remove hone/generated cms/local_tests cms/local cms/trivcat cms/generated atlas/borgeg atlas/instal atlas/generated atlas/SAM ops/generated dteam/CSCS dteam/generated</verbatim> -- Main.PabloFernandez - 2010-03-11
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Topic revision: r10 - 2012-07-18 - FabioMartinelli
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