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Message #75561
[Bug 1327563] Re: Long delay when mounting NFS shares
** Description changed:
+ SRU justification:
+
+ Impact: Kernel 3.13 shows a 16s delay when mounting NFS shares without
+ using gssd (kerberos authentication) because it does not detect whether
+ gssd is running at all or not.
+
+ Fix: This was fixed upstream in 3.14 by having gssd create a dummy pipe
+ which is used as an indication of it running. Cherry-picking 3 patches
+ from upstream gets rid of the delay.
+
+ Testcase: Trying to mount a NFS share with unix authentication will be
+ delayed by 16s when not forcing NFSv3 protocol (using -onfsvers=3 with
+ the mount command). After applying the patches the delay is gone.
+
+ ---
+
Summary:
After upgrading the kernel on Ubuntu 14.04 to 3.13.0-29-generic I found
that it can take a considerably longer amount of time to mount NFS
shares.
How to reproduce:
1. Install Ubuntu 14.04 on two machines. A minimal server install should be fine. One will act as a server, the other as a client.
2. Upgrade the kernel on the client machine to at least 3.13.0-27-generic.
3. Install the nfs-kernel-server package on the server.
4. Add a directory to /etc/exports and run service nfs-kernel-server start.
5. Install the nfs-common package on the client.
6. Attempt to mount the shared directory on the client.
Expected result:
The shared directory should be mounted on the client more or less
immediately.
Actual result:
The mount command hangs and eventually completes. In this test case it
takes 16 seconds consistently. On a production machine where the problem
was first discovered the time is considerably longer and essentially
makes it impossible to mount NFS shares.
Regression:
I have been able to reproduce the problem on clients running Linux
3.13.0-27-generic and later. The problem is not reproducible on clients
running Linux 3.13.0-24-generic. The problem is reproducible no matter
which kernel version is used on the server.
Tested client kernel versions:
Linux 3.13.0-29-generic #53-Ubuntu FAIL
Linux 3.13.0-27-generic #50-Ubuntu FAIL
Linux 3.13.0-24-generic #47-Ubuntu OK
Tested server kernel versions:
Linux 3.13.0-29-generic #53-Ubuntu OK
Linux 3.13.0-27-generic #50-Ubuntu OK
Linux 3.13.0-24-generic #47-Ubuntu OK
lsb_release -rd:
Description: Ubuntu 14.04 LTS
Release: 14.04
apt-cache policy linux-image-generic:
linux-image-generic:
- Installed: (none)
- Candidate: 3.13.0.29.35
- Version table:
- 3.13.0.29.35 0
- 500 http://se.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
- 500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
- 3.13.0.24.28 0
- 500 http://se.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
+ Installed: (none)
+ Candidate: 3.13.0.29.35
+ Version table:
+ 3.13.0.29.35 0
+ 500 http://se.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
+ 500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
+ 3.13.0.24.28 0
+ 500 http://se.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-29-generic 3.13.0-29.53
ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
Uname: Linux 3.13.0-29-generic x86_64
AlsaDevices:
- total 0
- crw-rw---- 1 root audio 116, 1 Jun 7 16:26 seq
- crw-rw---- 1 root audio 116, 33 Jun 7 16:26 timer
+ total 0
+ crw-rw---- 1 root audio 116, 1 Jun 7 16:26 seq
+ crw-rw---- 1 root audio 116, 33 Jun 7 16:26 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: [Errno 2] No such file or directory: 'fuser'
CRDA: Error: [Errno 2] No such file or directory: 'iw'
Date: Sat Jun 7 16:30:02 2014
HibernationDevice: RESUME=UUID=9c13108b-d40a-4881-b563-c477ed2e6804
InstallationDate: Installed on 2014-06-07 (0 days ago)
InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lsusb:
- Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
- Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
- Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
- Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
+ Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
+ Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
+ Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
+ Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: QEMU Standard PC (i440FX + PIIX, 1996)
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-29-generic root=UUID=9068010d-8332-47c8-ae62-ccc62ca57290 ro
RelatedPackageVersions:
- linux-restricted-modules-3.13.0-29-generic N/A
- linux-backports-modules-3.13.0-29-generic N/A
- linux-firmware N/A
+ linux-restricted-modules-3.13.0-29-generic N/A
+ linux-backports-modules-3.13.0-29-generic N/A
+ linux-firmware N/A
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/01/2011
dmi.bios.vendor: Bochs
dmi.bios.version: Bochs
dmi.chassis.type: 1
dmi.chassis.vendor: Bochs
dmi.modalias: dmi:bvnBochs:bvrBochs:bd01/01/2011:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-2.0:cvnBochs:ct1:cvr:
dmi.product.name: Standard PC (i440FX + PIIX, 1996)
dmi.product.version: pc-i440fx-2.0
dmi.sys.vendor: QEMU
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1327563
Title:
Long delay when mounting NFS shares
Status in “linux” package in Ubuntu:
Fix Released
Status in “linux” source package in Trusty:
Triaged
Bug description:
SRU justification:
Impact: Kernel 3.13 shows a 16s delay when mounting NFS shares without
using gssd (kerberos authentication) because it does not detect
whether gssd is running at all or not.
Fix: This was fixed upstream in 3.14 by having gssd create a dummy
pipe which is used as an indication of it running. Cherry-picking 3
patches from upstream gets rid of the delay.
Testcase: Trying to mount a NFS share with unix authentication will be
delayed by 16s when not forcing NFSv3 protocol (using -onfsvers=3 with
the mount command). After applying the patches the delay is gone.
---
Summary:
After upgrading the kernel on Ubuntu 14.04 to 3.13.0-29-generic I
found that it can take a considerably longer amount of time to mount
NFS shares.
How to reproduce:
1. Install Ubuntu 14.04 on two machines. A minimal server install should be fine. One will act as a server, the other as a client.
2. Upgrade the kernel on the client machine to at least 3.13.0-27-generic.
3. Install the nfs-kernel-server package on the server.
4. Add a directory to /etc/exports and run service nfs-kernel-server start.
5. Install the nfs-common package on the client.
6. Attempt to mount the shared directory on the client.
Expected result:
The shared directory should be mounted on the client more or less
immediately.
Actual result:
The mount command hangs and eventually completes. In this test case it
takes 16 seconds consistently. On a production machine where the
problem was first discovered the time is considerably longer and
essentially makes it impossible to mount NFS shares.
Regression:
I have been able to reproduce the problem on clients running Linux
3.13.0-27-generic and later. The problem is not reproducible on
clients running Linux 3.13.0-24-generic. The problem is reproducible
no matter which kernel version is used on the server.
Tested client kernel versions:
Linux 3.13.0-29-generic #53-Ubuntu FAIL
Linux 3.13.0-27-generic #50-Ubuntu FAIL
Linux 3.13.0-24-generic #47-Ubuntu OK
Tested server kernel versions:
Linux 3.13.0-29-generic #53-Ubuntu OK
Linux 3.13.0-27-generic #50-Ubuntu OK
Linux 3.13.0-24-generic #47-Ubuntu OK
lsb_release -rd:
Description: Ubuntu 14.04 LTS
Release: 14.04
apt-cache policy linux-image-generic:
linux-image-generic:
Installed: (none)
Candidate: 3.13.0.29.35
Version table:
3.13.0.29.35 0
500 http://se.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
3.13.0.24.28 0
500 http://se.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-29-generic 3.13.0-29.53
ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
Uname: Linux 3.13.0-29-generic x86_64
AlsaDevices:
total 0
crw-rw---- 1 root audio 116, 1 Jun 7 16:26 seq
crw-rw---- 1 root audio 116, 33 Jun 7 16:26 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: [Errno 2] No such file or directory: 'fuser'
CRDA: Error: [Errno 2] No such file or directory: 'iw'
Date: Sat Jun 7 16:30:02 2014
HibernationDevice: RESUME=UUID=9c13108b-d40a-4881-b563-c477ed2e6804
InstallationDate: Installed on 2014-06-07 (0 days ago)
InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lsusb:
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: QEMU Standard PC (i440FX + PIIX, 1996)
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-29-generic root=UUID=9068010d-8332-47c8-ae62-ccc62ca57290 ro
RelatedPackageVersions:
linux-restricted-modules-3.13.0-29-generic N/A
linux-backports-modules-3.13.0-29-generic N/A
linux-firmware N/A
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/01/2011
dmi.bios.vendor: Bochs
dmi.bios.version: Bochs
dmi.chassis.type: 1
dmi.chassis.vendor: Bochs
dmi.modalias: dmi:bvnBochs:bvrBochs:bd01/01/2011:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-2.0:cvnBochs:ct1:cvr:
dmi.product.name: Standard PC (i440FX + PIIX, 1996)
dmi.product.version: pc-i440fx-2.0
dmi.sys.vendor: QEMU
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References
