Official How-To
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:
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
And we copy them to the target host:
scp /tmp/verify.md5 /tmp/pnfs.sql /tmp/files.lst root@storage22:
And also an initialization SQL script from pnfs-dump RPM:
scp /opt/pnfs/share/sql/prep-chimera-for-migration.sql root@storage22:
Import pnfs dumps into Chimera
Check everything worked fine
The first test is the MD5sum. In the Chimera node, with the filesystem mounted in /mnt as usual, perform
cd /mnt/pnfs/lcg.cscs.ch/
time md5sum -c /root/verify.md5 | tee /root/verify.md5.result | grep -v :\ OK$
The second check (
StorageInfo) needs to run on the chimera node with chimera unmounted and pnfs mounted:
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
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:
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
--
PabloFernandez - 2010-03-11