[Moosefs-users] Creating sparse file

[Jakub M. <ja...@31...>]

Hello,
Im trying to create sparse files on mfs but it isn't working.

On MFS:
local:/mfs# dd if=/dev/zero of=jakub.test bs=4096 count=0 seek=1000
0 bytes (0 B) copied, 0.000205242 s, 0.0 kB/s
local:/mfs# du -h jakub.test
4.0M    jakub.test

On local disk:
local:~# dd if=/dev/zero of=jakub.test bs=4096 count=0 seek=1000
0 bytes (0 B) copied, 1.0481e-05 s, 0.0 kB/s
local:~# du -h jakub.test
0       jakub.test

As you can see on my local hdd everything is fine, file size is 0. On MFS file size is 4Mb.

What about cp?
local:~# cp --sparse=always jakub.test /mfs/
local:/mfs# du -h /mfs/jakub.test
4.0M    jakub.test

local:/mfs# cp --sparse=always jakub.test /root/jakub.test2
local:~# du -h /root/jakub.test2
0       jakub.test2

After cp from MFS to local hdd sparse file has good size.

What im doing wrong? Why all sparse files sizes on MFS are >0?
 
-- 
Jakub Mroziński