Bug 1100026
| Summary: | 'df' command omits mounted NFS shares with the same superblock unless '-a' flag is used. (improve deduplication) | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Kyle Squizzato <ksquizza> | |
| Component: | coreutils | Assignee: | Ondrej Vasik <ovasik> | |
| Status: | CLOSED ERRATA | QA Contact: | Vaclav Danek <vdanek> | |
| Severity: | medium | Docs Contact: | ||
| Priority: | urgent | |||
| Version: | 7.0 | CC: | feyang, fkrska, jayashree_doijad, jherrman, jscotka, kdudka, marbet, modellera, ooprala, ovasik, paulds, sreber, vdanek | |
| Target Milestone: | rc | Keywords: | FutureFeature, Reproducer, ZStream | |
| Target Release: | 7.1 | |||
| Hardware: | All | |||
| OS: | Linux | |||
| Whiteboard: | ||||
| Fixed In Version: | coreutils-8.22-13.el7 | Doc Type: | Bug Fix | |
| Doc Text: |
Previously, if multiple NFS mount points shared a superblock, the "df" command only listed one of them unless the "-a" option was used. This update improves the filtering methods of "df", and the command now properly displays all NFS mount points on the same superblock.
|
Story Points: | --- | |
| Clone Of: | ||||
| : | 1247128 (view as bug list) | Environment: | ||
| Last Closed: | 2015-11-19 12:44:22 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 1247128 | |||
So the behavior is purely caused by the deduplication most likely related to this upstream commit https://lists.gnu.org/archive/html/coreutils/2013-01/txtBi0iwyxKsd.txt Maybe there needs to be some form of logic to not deduplicate NFS shares? Yes, it is caused by the /etc/mtab -> /proc/mounts symlink. This caused massive ammount of duplicate entries, therefore multiple bug reports/complains. Deduplication was added in cooperation with upstream, but it is probably too aggressive for some of the filesystems - NFS is likely not the only one. Adding FutureFeature keyword, there were multiple complains about the deduplication, but every solution had some drawback so far. We should resolve it somehow in RHEL 7.1+, though. *** Bug 1110624 has been marked as a duplicate of this bug. *** As a sidenote, upstream is discussing removing deduplication for remote filesystems. http://lists.gnu.org/archive/html/coreutils/2014-10/msg00073.html In addition http://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=097897bd2c9de5723af24b3848d6d922a862064b improves the docs so it mentions the "deduplication". Part will be covered by #1197463 (to some extend duplicates), this one will likely be about "extending documentation as well". *** Bug 1221170 has been marked as a duplicate of this bug. *** use case from #9 tested and seems OK with coreutils-8.22-13.el7 in my environment: # rpm -q coreutils coreutils-8.22-11.el7.x86_64 # df -a|grep /mnt /etc/auto.direct 30487552 23447424 5491456 82% /mnt # df -a|grep /mnt /etc/auto.direct 30487552 23447424 5491456 82% /mnt rhel62:/tmp 30487552 23447424 5491456 82% /mnt # df |grep /mnt <empty> not expected ^^ # rpm -q coreutils coreutils-8.22-13.el7.x86_64 # df -a|grep /mnt /etc/auto.direct - - - - /mnt rhel62:/tmp 30487552 23447552 5491328 82% /mnt # df |grep /mnt rhel62:/tmp 30487552 23447552 5491328 82% /mnt expected ^^ Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2015-2160.html on rhel7.3 the issue seems still exists, the reproduce steps as below:
Server：
[root@NFS-Server ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.3 (Maipo)
[root@NFS-Server ~]# uname -a
Linux NFS-Server 3.10.0-514.el7.x86_64 #1 SMP Wed Oct 19 11:24:13 EDT 2016 x86_64 x86_64 x86_64 GNU/Linux
[root@NFS-Server ~]# cat /etc/exports
/nfs_share 192.168.53.0/24(rw,sync,no_root_squash)
Client：
[root@NFS-Client ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.3 (Maipo)
[root@NFS-Client ~]# uname -a
Linux NFS-Client 3.10.0-514.el7.x86_64 #1 SMP Wed Oct 19 11:24:13 EDT 2016 x86_64 x86_64 x86_64 GNU/Linux
[root@NFS-Client ~]# mount -t nfs 192.168.53.128:/nfs_share /test1
[root@NFS-Client ~]# mount -t nfs 192.168.53.128:/nfs_share /test2
[root@NFS-Client ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/rhel-root 46G 3.0G 43G 7% /
devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs 1.9G 84K 1.9G 1% /dev/shm
tmpfs 1.9G 9.0M 1.9G 1% /run
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/sda1 1014M 173M 842M 18% /boot
tmpfs 378M 12K 378M 1% /run/user/42
tmpfs 378M 0 378M 0% /run/user/0
192.168.53.128:/nfs_share 46G 3.0G 43G 7% /test1
[root@NFS-Client ~]# mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
devtmpfs on /dev type devtmpfs (rw,nosuid,size=1916868k,nr_inodes=479217,mode=755)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpuacct,cpu)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_prio,net_cls)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
configfs on /sys/kernel/config type configfs (rw,relatime)
/dev/mapper/rhel-root on / type xfs (rw,relatime,attr2,inode64,noquota)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=36,pgrp=1,timeout=300,minproto=5,maxproto=5,direct)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
mqueue on /dev/mqueue type mqueue (rw,relatime)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw,relatime)
nfsd on /proc/fs/nfsd type nfsd (rw,relatime)
/dev/sda1 on /boot type xfs (rw,relatime,attr2,inode64,noquota)
tmpfs on /run/user/42 type tmpfs (rw,nosuid,nodev,relatime,size=386556k,mode=700,uid=42,gid=42)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
gvfsd-fuse on /run/user/42/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=42,group_id=42)
tmpfs on /run/user/0 type tmpfs (rw,nosuid,nodev,relatime,size=386556k,mode=700)
192.168.53.128:/nfs_share on /test1 type nfs4 (rw,relatime,vers=4.0,rsize=524288,wsize=524288,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.53.129,local_lock=none,addr=192.168.53.128)
192.168.53.128:/nfs_share on /test2 type nfs4 (rw,relatime,vers=4.0,rsize=524288,wsize=524288,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.53.129,local_lock=none,addr=192.168.53.128)
[root@NFS-Client ~]# df -at nfs
df: no file systems processed
I believe this will be eventually fixed with bug #1042840. |
Description of problem: The 'df' command omits mounted NFS shares with the same superblock unless the '-a' to show dummy filesystems is used. If I create a new share underneath the existing /share/ directory I can provide an example of this behavior: # df -ht nfs Filesystem Size Used Avail Use% Mounted on scooby.usersys.redhat.com:/share 360G 212G 131G 62% /mnt/nfs I need the 'a' flag to make the share show up: # df -hat nfs Filesystem Size Used Avail Use% Mounted on scooby.usersys.redhat.com:/share 360G 212G 131G 62% /mnt/nfs scooby.usersys.redhat.com:/share/test 360G 212G 131G 62% /mnt/nfs_share If I modify my /etc/exports file on the NFS server so that each export has a different fsid, thus a different NFS superblock it fixes the issue: /share *(rw,sync,no_subtree_check,no_root_squash,insecure,fsid=2) /share/test *(rw,sync,fsid=3) And the -a is no longer needed: # df -ht nfs Filesystem Size Used Avail Use% Mounted on scooby.usersys.redhat.com:/share 360G 212G 131G 62% /mnt/nfs scooby.usersys.redhat.com:/share/test 360G 212G 131G 62% /mnt/nfs_share crash> mount | grep 'nfs ' MOUNT SUPERBLK TYPE DEVNAME DIRNAME ffff880018707400 ffff88003a5c4c00 nfs scooby.usersys.redhat.com:/share /mnt/nfs ffff88003becc100 ffff88001cf8c800 nfs scooby.usersys.redhat.com:/share/test /mnt/nfs_share Once we remove the fsid's I have identical superblocks, thus 'df' omits the second share. ffff880014faa700 ffff88003cd16800 nfs scooby.usersys.redhat.com:/share/test /mnt/nfs_share ffff880018619300 ffff88003cd16800 nfs scooby.usersys.redhat.com:/share /mnt/nfs Version-Release number of selected component (if applicable): coreutils-8.22-11.el7 How reproducible: Always Steps to Reproduce: 1. Mount two shares from the same underlying directory tree (so that they share a common NFS superblock) for example: /share/foo /share/bar 2. Run 'df' The behavior can be corrected by adding an fsid to each export, thusly modifying the NFS superblocks for each of the shares. Actual results: 'df' omits shares with the same superblock Expected results: 'df' should show all underlying NFS shares mounted at different directories regardless of their superblock. Additional info: I think this can be argued as NOTABUG, however this implementation: 1) Is a significant change in behavior for the 'df' command from previous Linux (and non-Linux) implementations 2) Ignores the possibility that NFS servers may implement things like subdirectory-level quotas.