[Lustre-discuss] OST node filling up and aborting write

[Kevin Van Maren]

minh diep wrote:
>>> No.  By default, stripesize == 1.  In order to get a single file onto
>>> multiple OSTs you will need to explicitly set a striping policy either
>>> on the file you are going to write into or the directory the file is in.
>>>       
>> Then what is stripesize=-1 used for? (when specified for the filesystem, 
>> and not a file or a directory). Can you give me an example?
>>     
"-1" means "all available".  So with a 1MB stripe size, it will write 
1MB to an OST, then write 1MB
to the next, etc, until it runs out of OSTs.  Then it will put the next 
chunk back on the first OST and repeat.

> You can only setstripe on a directory, not a file.
>   
Not entirely correct: you cannot change the stripe on an _existing_ 
file, but "lfs setstripe" will create a
0-byte file with the specified striping (think "touch").  But "lfs 
setstripe" is normally used on directories.

Any file or directory being created inherits the stripe info from the 
directory it is in.  If that value is "0",
it uses the system default (normally 1).

For large files, you should set the stripe to "-1" or some value > 1 (4 
is good with 4 OSTs).

I think we've now beaten this thread to death...

Kevin