When using Scale-Out File Server (SOFS) shares, the same share is exposed by multiple share servers through a single Distributed Network Name.
When a host goes down, the share connections should be automatically reestablished using a different share server.
The Linux CIFS client doesn't seem to support this, although persistent handles are supported. If a host goes down, the share becomes unavailable, while the client seems to enter an endless loop, attempting to use the same share server address. Subsequent mount attempts will fail as well.
SMB Witness support would also be desired, as this would reduce failover time (currently marked as TODO[1]).
I've tested Ubuntu 16.04 (4.4.0) and Ubuntu 18.04 (4.15.0) as well as the latest upstream kernel (4.19). When using 4.15.0, the SOFS share cannot be mounted at all, as described in a different bug report[2].
[1] https://github.com/torvalds/linux/blob/3de5e974ba65fd1629fb6ea0cb5222c78b1580ec/Documentation/filesystems/cifs/TODO#L58-L62
[2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1792580
---
ProblemType: Bug
ApportVersion: 2.20.9-0ubuntu7.3
Architecture: amd64
DistroRelease: Ubuntu 18.04
Package: linux (not installed)
ProcEnviron:
TERM=xterm-256color
PATH=(custom, no user)
LANG=C.UTF-8
SHELL=/bin/bash
Tags: bionic uec-images
Uname: Linux 4.19.0-041900rc4-generic x86_64
UnreportableReason: The running kernel is not an Ubuntu kernel
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:
_MarkForUpload: True
---
AlsaDevices:
total 0
crw-rw---- 1 root audio 116, 1 Sep 18 08:17 seq
crw-rw---- 1 root audio 116, 33 Sep 18 08:17 timer
AplayDevices: Error: [Errno 2] No such file or directory
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CRDA: N/A
DistroRelease: Ubuntu 16.04
IwConfig: Error: [Errno 2] No such file or directory
Lsusb: Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: QEMU Standard PC (i440FX + PIIX, 1996)
Package: linux (not installed)
PciMultimedia:
ProcEnviron:
TERM=xterm-256color
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB:
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-135-generic root=UUID=4e0b126d-f842-4ae8-bd4b-7ebf2cd44df6 ro console=tty1 console=ttyS0
ProcVersionSignature: Ubuntu 4.4.0-135.161-generic 4.4.140
RelatedPackageVersions:
linux-restricted-modules-4.4.0-135-generic N/A
linux-backports-modules-4.4.0-135-generic N/A
linux-firmware N/A
RfKill: Error: [Errno 2] No such file or directory
Tags: xenial uec-images
Uname: Linux 4.4.0-135-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:
_MarkForUpload: True
dmi.bios.date: 04/01/2014
dmi.bios.vendor: SeaBIOS
dmi.bios.version: 1.10.2-1ubuntu1
dmi.chassis.type: 1
dmi.chassis.vendor: QEMU
dmi.chassis.version: pc-i440fx-bionic
dmi.modalias: dmi:bvnSeaBIOS:bvr1.10.2-1ubuntu1:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-bionic:cvnQEMU:ct1:cvrpc-i440fx-bionic:
dmi.product.name: Standard PC (i440FX + PIIX, 1996)
dmi.product.version: pc-i440fx-bionic
dmi.sys.vendor: QEMU
apport information