AdvFS Quota FAQ

crash

Q: quota.user and quota.group looks very big
# ls -l quot*
-rw-r-----   1 root     operator    8192 Sep  3 15:00 quota.group
-rw-r-----   1 root     operator 4194304 Sep  3 15:00 quota.user
A: These two files are used to maintain the AdvFS file system, every user and group has a map in the file, the size depends on user id and group id. They are sparse files.    A sparse file is created by a program that uses a seek system call to jump around inside the file and write data in a non-contiguous manor.  The file system only allocates space in the area where the program writes.  The file system maintains a map of allocated blocks for each  file and uses this map to know when to return zeros if an unallocated area is read, or to allocate storage if data is written to a currently unallocated area.
The real size of them is small. You can check it with ls –ls or du, for example:
# ls -ls quot*
8 -rw-r-----   1 root     operator    8192 Sep  3 15:00 quota.group
96 -rw-r-----   1 root     operator 4194304 Sep  3 15:00 quota.user
# du -k quo*
8       quota.group
96      quota.user
Normally backup utility is aware of the spare file and can get a copy with the real size, for example
# tar cvf test.tar quot*
a quota.group 16 Blocks
a quota.user 8192 Blocks

吹拂的晨风

嗯，好！