[lustre-discuss] mgsnode notation in mkfs and tunefs

[Thomas Roth]

Hi all,

(we are now on Lustre 2.10.2.)
It seems there is still a difference in how to declare --mgsnode between mkfs.lustre and tunefs.lustre.
For an OST, I did:

 > mkfs.lustre --ost --backfstype=zfs  --mgsnode=10.20.3.0 at o2ib5:10.20.3.1 at o2ib5 --... osspool0/ost0

This OST mounts, is usable, all fine.


Then I had to writeconf, and out of tradition, added --erase-params to the command - so I had to add 
the mgsnodes as well:

 > tunefs.lustre --erase-param --writeconf --mgsnode=10.20.3.0 at o2ib5:10.20.3.1 at o2ib5 osspool0/ost0

This did not mount, so I repeated this and other writeconfs, and ended up with

 > tunefs.lustre --dryrun  osspool0/ost0
checking for existing Lustre data: found

    Read previous values:
Target:     hebe-OST0000
Index:      0
Lustre FS:  hebe
Mount type: zfs
Flags:      0x142
               (OST update writeconf )
Persistent mount opts:
Parameters: 
mgsnode=10.20.3.0 at o2ib5:10.20.3.1 at o2ib5:10.20.3.0 at o2ib5:10.20.3.1 at o2ib5:10.20.3.0 at o2ib5:10.20.3.1 at o2ib5


Seems I could have added more and more mgsnodes, and never gotten a good OST ;-)

I repaired this by:

 > tunefs.lustre --erase-param mgsnode   osspool0/ost0
 > tunefs.lustre --writeconf  --mgsnode=10.20.3.0 at o2ib5 --mgsnode=10.20.3.1 at o2ib5 osspool0/ost0



This cluster is not yet in use - but if this happens with a production system, when --writeconf is 
anyhow your last resort - uncomfortable situation.


Cheers
Thomas