On Wed, Jul 04, 2012 at 08:20:07AM -0400, Ric Wheeler wrote:

On 07/03/2012 11:06 PM, Phillip Susi wrote:
For reasonably sized files, you might just as well really write out
the full file with "write" (do pre-allocation the old fashioned
way).

Performance of course depends on the size of the file, but for a 1GB
file you can do this in a few seconds and prevent fragmentation and
totally eliminate the performance of flipping extents.

How large is the file you need to pre-allocate? How long does the
job typically run (minutes? hours? days?) :)

We have over one thousand servers with ten or more 2T SATA disks, and we
need to pre-allocate a lot of files with fixed size until the space of
every disks is occupied when the application starts up on first time.
Meanwhile this number is increasing every months.  It will be absolutely
a nightmare for SA if we use the old fashioned way to do pre-allocation.

Regards,
Zheng