why append 1 byte data for file ,size change 8k
[root@WOLK-TECH tmp]# ll -sh joy
4.0K -rw-r--r-- 1 root root 0 Oct 30 17:46 joy
[root@WOLK-TECH tmp]# echo 1 > joy
[root@WOLK-TECH tmp]# ll -sh joy
8.0K -rw-r--r-- 1 root root 2 Oct 31 03:23 joy

What we are trying to discern at this point is why his info shows so, but mine does not. Just look at the numbers above, I won't paste them again.

The file is 0 bytes long. In his case, ls reports 4kb and stat says 8 disk blocks (disk block = 512 bytes, regardless of your fs). In my case, ls reports 0 kb and stat reports 0 disk blocks.

huyangyang, can you show us the mount line for that concrete partition where you are creating the file? Just in case.

this???
[root@WOLK-TECH test]# mount
/dev/sda3 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/dev/sdb on /mnt type ext3 (rw)
[root@WOLK-TECH test]# df -T
Filesystem Type 1K-blocks Used Available Use% Mounted on
/dev/sda3 ext3 7002712 2630968 4010284 40% /
/dev/sda1 ext3 101086 11139 84728 12% /boot
tmpfs tmpfs 257744 0 257744 0% /dev/shm
/dev/sdb ext3 20642428 176200 19417652 1% /mnt

Yes, that's what I wanted to see, just in case you were using some rare mount option or something, but everything seems quite normal to me.

If no one around can give a reasoned response I'd ask on the kernel subsection of the forum, maybe someone around there can give a better response, the reason for this must lie forcingly in the file system driver.

thank you!!!