Re: [Bacula-users] vchanger 1.0.1 says "No slots in changer to scan"

Hi Josh,

Thanks for your quick response.

On Fri, May 6, 2016 at 7:40 PM, Josh Fisher <jfisher AT pvct DOT com> wrote:

On 5/6/2016 3:07 AM, Pann Tolk wrote:

Hi Josh,

......

May 06 14:34:06 deneb systemd-udevd[2578]: '/usr/libexec/vchanger/vchanger-launch-mount.sh 1fde15be-83a4-4b67-accc-378d5fa10ea7'(err) ' device-enumerator: scanning /sys/class'
====>> May 06 14:34:06 deneb systemd-udevd[2578]: Process '/usr/libexec/vchanger/vchanger-launch-mount.sh 1fde15be-83a4-4b67-accc-378d5fa10ea7' succeeded.
^^^
^^^ Here, udevd says that /usr/libexec/vchanger/vchanger-launch-mount.sh script has completed running successfully.

Udev expects any scripts launched by udev rules to execute quickly and not cause delays, therefore the vchanger-launch-mount.sh script launched by udev simply causes the /usr/libexec/vchanger/vchanger-mount-uuid.sh script to be invoked as a background process and then terminates. So a success simply means that vchanger-launch-maount.sh successfully invoked vchanger-mount-uuid.sh in a background process, not that it mounted successfully.

Ah yes! My bad. I did read and also looked at /usr/libexec/vchanger/vchanger-launch-mount.sh before and knows that it invokes /usr/libexec/vchanger/vchanger-mount-uuid.sh as a background process. Wasn't thinking properly earlier. Sorry.

The default mountdir is /mnt. To mount under say /mnt/vchanger it is necessary to set MOUNTDIR=/mnt/vchanger in /etc/sysconfig/vchanger.

Yes, my /etc/sysconfig/vchanger is as below:

[root@deneb ~]# ls -lt /etc/sysconfig/vchanger
-rw-r--r-- 1 root root 39 Jun 10 2015 /etc/sysconfig/vchanger
[root@deneb ~]# cat /etc/sysconfig/vchanger
MOUNT_DIR=/mnt/vchanger
MOUNT_OPTIONS=
[root@deneb ~]#

It's still the original file that comes with the RPM package.

Alternatively, you can use a line like

UUID=1fde15be-83a4-4b67-accc-378d5fa10ea7 /any/existing/directory/name ext4 defaults,rw,relatime,data="" 0 0

in /etc/fstab to cause vchanger-mount-uuid.sh to mount it wherever you like. When specified as magazine=uuid:, vchanger will lookup the mountpoint using libudev and so doesn't really care where it gets mounted. When using magazine=/some/static/path, it must be mounted at the specified path.

Ok. I'll have to muck with /etc/fstab now to add those entries to mount the filesystem magazines to /mnt/vchanger/<UUID>

You can umount the partition and then run vchanger-mount-uuid.sh (as root) with the uuid as its only parameter to see what it does. Unfortunately, the script is very simple and doesn't provide logging.

I did the test. First, I inserted the disk and executed mount | grep <UUID> :

[root@deneb ~]# mount | grep 1fde15be-83a4-4b67-accc-378d5fa10ea7
[root@deneb ~]#

Nothing! vchanger-mount-uuid.sh does not mount the drive.

Next, I ran /usr/libexec/vchanger/vchanger-mount-uuid.sh:

[root@deneb ~]# /usr/libexec/vchanger/vchanger-mount-uuid.sh 1fde15be-83a4-4b67-accc-378d5fa10ea7
checking dev
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
[root@deneb ~]# mount | grep 1fde15be-83a4-4b67-accc-378d5fa10ea7
/dev/sdb1 on /mnt/vchanger/1fde15be-83a4-4b67-accc-378d5fa10ea7 type ext4 (rw,relatime,data="">

So this is weird, running /usr/libexec/vchanger/vchanger-mount-uuid.sh manually is able to mount it. Note that autofs is disabled. So, it shouldn't be interfering with udev.

Anyway, to test further, I manually mount it:

[root@deneb ~]# mount /dev/disk/by-uuid/1fde15be-83a4-4b67-accc-378d5fa10ea7 /mnt/vchanger/1fde15be-83a4-4b67-accc-378d5fa10ea7/
[root@deneb ~]# mount | grep vchanger
/dev/sdb1 on /mnt/vchanger/1fde15be-83a4-4b67-accc-378d5fa10ea7 type ext4 (rw,relatime,data=""> [root@deneb ~]#

Then, I did what you mentioned:- I modified /etc/vchanger/vchanger01.conf and changed the bconsole="/usr/sbin/bconsole" line to bconsole = "".

Then I tried the following again.

[root@deneb ~]# vchanger /etc/vchanger/vchanger01.conf listmags
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
0:18:1:/mnt/vchanger/1fde15be-83a4-4b67-accc-378d5fa10ea7
1:::
2:::
3:::

So vchanger is working properly when run as root. What does it do when you run that same command as user bacula:tape? Are you sure bacula-sd is running as user bacula:tape? vchanger must run as the same user as bacula-sd. It could still be a permissions issue. You can set 'log level = 7' and 'logfile = /path/to/logfile' in vchanger.conf to debug vchanger, but you must run it as user bacula:tape to debug if it is a permissions issue.

I believe bacula-sd is running as bacula:tape:

[root@deneb ~]# ps -aux | grep bacula
bacula 2239 0.0 0.4 200828 9396 ? Ssl 23:59 0:00 /usr/sbin/bacula-dir -f -c /etc/bacula/bacula-dir.conf -u bacula -g bacula
bacula 2248 0.0 0.3 254136 7600 ? Ssl 23:59 0:00 /usr/sbin/bacula-sd -f -c /etc/bacula/bacula-sd.conf -u bacula -g tape

As requested, I set 'log level =7':

[root@deneb ~]# cat /etc/vchanger/vchanger01.conf | grep -v "^[#]"
Storage Resource = "vchanger01"
User = bacula
group = tape
work dir = "/var/spool/vchanger/vchanger01"
logfile = "/var/log/vchanger/vchanger01.log"
log level = 7
bconsole = ""
bconsole config = /etc/bacula/bconsole.conf
default pool = "Scratch"

magazine = UUID:1fde15be-83a4-4b67-accc-378d5fa10ea7
magazine = UUID:412060d2-7be4-4719-8089-2ee6cfd28624
magazine = UUID:20d986c1-9391-467e-9f73-232b53fba377
magazine = UUID:fa48ed8d-2e63-4c27-8670-c943822d2cd0

Run "vchanger /etc/vchanger/vchanger01.conf listmags" as bacula:tape:-

[root@deneb ~]# runuser bacula -g tape
bash-4.3$ id
uid=133(bacula) gid=33(tape) groups=33(tape)
bash-4.3$ vchanger /etc/vchanger/vchanger01.conf listmags
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
device-enumerator: scan all dirs
device-enumerator: scanning /sys/bus
device-enumerator: scanning /sys/class
0:18:1:/mnt/vchanger/1fde15be-83a4-4b67-accc-378d5fa10ea7
1:::
2:::
3:::

And from the /var/log/vchanger/vchanger01.log:-

May 07 00:56:24: created lockfile for pid 3308
May 07 00:56:24: restored state of magazine 0
May 07 00:56:24: magazine 0 has 18 volumes on /mnt/vchanger/1fde15be-83a4-4b67-accc-378d5fa10ea7
May 07 00:56:24: 18 volumes on magazine 0 assigned slots 1-18
May 07 00:56:24: magazine 1 is not mounted
May 07 00:56:24: magazine 2 is not mounted
May 07 00:56:24: magazine 3 is not mounted
May 07 00:56:24: saved state of magazine 0
May 07 00:56:24: saved dynamic configuration (max used slot: 37)
May 07 00:56:24: drive 0 previously unloaded
May 07 00:56:24: ==== preforming LISTMAGS command pid=3308
May 07 00:56:24: SUCCESS listing magazine info to stdout
May 07 00:56:24: removing lockfile for pid 3308

bash-4.3$ bconsole
Connecting to Director deneb.chuakt.local:9101
1000 OK: 102 bacula-dir Version: 7.4.0 (16 January 2016)
Enter a period to cancel a command.
*update slots
Automatically selected Catalog: MyCatalog
Using Catalog "MyCatalog"
Automatically selected Storage: vchanger01
Connecting to Storage daemon vchanger01 at deneb.chuakt.local:9103 ...
3306 Issuing autochanger "slots" command.
Device "SATA-vchanger01" has 0 slots.
No slots in changer to scan.

So, it does not seem to be any permission issue...unless I'm wrong.

Still looking forward to fix this issue.

Thanks

Pann

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