zfsonlinux/zfs — Issue #550: specific snapshot not working, kernel: 3.1.0-1-amd64
Author: martinhelmer
Created: 2012-02-02 14:17:20+00:00
State: open

Running with
*zfsonlinux-zfs-e29be02
*/zfsonlinux-spl-3c6ed54
(master head @ 29 jan)

System: debian wheezy (testing)
kernel: 3.1.0-1-amd64

when i make a snapshot of one particular zfs filesystem the snapshot is empty.

environment:

```
root@carmencita:~# zpool status
pool: tank
state: ONLINE
scan: none requested
config:

NAME STATE READ WRITE CKSUM
tank ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
scsi-SATA_WDC_WD800JD-00L_WD-WMAM9T711455 ONLINE 0 0 0
scsi-SATA_WDC_WD800JD-22L_WD-WMAM9L044682 ONLINE 0 0 0

root@carmencita:~# zpool get all tank
NAME PROPERTY VALUE SOURCE
tank size 74.5G -
tank capacity 1% -
tank altroot - default
tank health ONLINE -
tank guid 11272690528899556785 default
tank version 28 default
tank bootfs - default
tank delegation on default
tank autoreplace off default
tank cachefile - default
tank failmode wait default
tank listsnapshots on local
tank autoexpand off default
tank dedupditto 0 default
tank dedupratio 1.00x -
tank free 73.7G -
tank allocated 790M -
tank readonly off -
tank ashift 0 default
```
starting point:

```
root@carmencita:~# zfs list
NAME USED AVAIL REFER MOUNTPOINT
tank 1010M 72.3G 790M /tank
tank@1 0 - 790M -
tank@2 0 - 790M -
tank/Documents 110M 72.3G 30K /nfsshare/Documents
tank/Documents@hej 0 - 30K -
tank/Documents@q 0 - 30K -
tank/Documents@snap2 0 - 30K -
tank/Documents/test1 110M 72.3G 110M /mnt/test1
tank/Documents/test1@snap1 19K - 30K -
tank/Documents/test1@snap2 0 - 110M -
```

now if i do the following:

```
zfs create tank/Documents@snap1
cd /nfsshare/Documents/
touch file1
touch file2
touch file3
zfs snapshot tank/Documents@snap1
zfs send tank/Documents@snap1 | zfs receive tank/target1
```

and then look in /tank/target1

the directory is empty.

repeating the process with a freshly created filesystem (instead of tank/Documents) works fine.

(the tank/Documents/test1 filesystem is an exampe of this. it was created while troubleshooting this issue)

the problem seems to be related to this particular filesystem (tank/documents) which i have had up for a few days, and written some subdirectories to through NFS sharing.

(legacy nfs config, not zfs-nfs)

details available upon request