Fix raidcheck error on Xenserver 6.5

After configuring a software RAID to host my VMs on my Xenserver 6.5 instance I began receiving odd e-mails once a week. The e-mails simply said:

/usr/sbin/raid-check: line 62: declare: -A: invalid option 
declare: usage: declare [-afFirtx] [-p] [name[=value] ...]

It turns out /usr/sbin-raid-check is a bash script called from the file /etc/cron.d/raid-check. It’s a weekly cron job designed to “scrub” the RAID array. I was getting these e-mails because I had configured my xen server to e-mail me anything sent to root, which includes messages encountered during cron jobs.

There appears to be a typo in the raid-check script. Line 62 of raid-check reads:

declare -A check

After reading the syntax of the declare command, I believe the issue is the fact that the A is capitalized. I commented out that line and replaced it with

declare -a check

That seemed to work. No more weird errors coming from my xenserver.

Install Splunk Universal Forwarder on Linux

I do this infrequently enough that I decided I should really write this down. Below is the quick and dirty way to get the Splunk universal forwarder installed on a new Linux  system. Thanks to byteschef for the information used to create this guide.

Download the latest splunk .RPM from their site and install it via RPM -i <filename> (if RedHat based) or dpki -i <filename> if debian based.

Run the following commands as root:

cd /opt/splunkforwarder/bin
./splunk start --accept-license
./splunk enable boot-start
./splunk add forward-server <IP/hostname of splunk server>:9997 -auth admin:changeme
./splunk add monitor /var/log
./splunk edit user admin -password NEW_PASSWORD -auth admin:changeme
./splunk restart

If there are any other directories you want monitored other than /var/log (application logs, for example) then issue:

./splunk add monitor <directory to monitor>


Fix Owncloud 8.1.1 samba shares not working

It never seems to go smoothly, does it? I just upgraded my version of Owncloud from 8.0.4 to 8.1.1 on my Ubuntu Trusty Tahr 14.04 VM. After the upgrade I noticed that all my samba (SMB) shares were gone. The logs were not very helpful, full of things like these:

Exception: {"Exception":"Icewind\\SMB\\Exception\\InvalidHostException","Message":"","Code":0,"Trace":"#0 \/var\/www\/owncloud\/apps\/files_external\/3rdparty\/icewind\/smb\/src\/Connection.php(37): Icewind\\SMB\\Connection

Additionally errors like this were showing up:

Your web server is not yet set up properly to allow file synchronization because the WebDAV interface seems to be broken.

After much digging I discovered this post which had a suggestion to install libsmbclient-php. In Ubuntu 14.04 it involves this command:

sudo apt-get install php5-libsmbclient

That did the trick! After installing php5-libsmbclient my samba shares worked once more.


Xenserver SSH backup script

Citrix Xenserver is an amazing hypervisor with pretty much every function released to you for free. One thing they do not handle, however, is automated backups.

I have hacked together a backup script for myself that seems to work fairly well. It is my own mix of this and this script along with some logic for e-mail reporting that I came up with myself. It does not require any modification of the xenserver host at all (no need to mount anything!) with the exception of adding a public key to the xenserver’s authorized_keys file.

This script can be run on anything with BASH and the appropriate UNIX tools (even other xenservers if you want) and uses SSH to initiate and transfer the backups to a location of your choosing.

Place this script on the machine you want to be initiating / saving the backups on. It requires that you generate an SSH public/private key pair, which can be done with this command:


Add the resulting .pub file’s contents to your xenserver’s /root/.ssh/authorized_keys file (create it if it doesn’t exist.) Take note of the location of the private key file that was generated with that command and put that path in the script.

You can download the script here or view it below. This script has been working pretty well for me. Note it will not work with any VMs that have spaces in their names. I was too lazy to debug this so I just renamed the problem VMs to remove the spaces. Enjoy!


# Modified August 30, 2015 by Nicholas Jeppson
# Taken from and modified to allow for ssh backups
# Additional insight taken from

# [Usage & Config]
# This script involves two computers: a xenserver machine and a backup machine.
# Put this script on the backup server and run with any account that has privileges to the desired export directory.
# This script assumes you have already created a private and public key pair on the backup server
# as well as adding respective the public key to the xenserver authorized_keys file.
# [How it works]
# Step1: Snapshots each VM on the xen server
# Step2: Backs up the snapshots to specified location
# Step3: Deletes temporary snapshot created in step 1
# Step4: Deletes old VM backups as defined later in this file
# [Note]
# This script will only work with VMs that don't have spaces in their names
# Please make sure you have enough disk space for BACKUP_PATH, or backup will fail
# Tested on xenserver 6.5
# Modify the variables in the config section below to suit your particular environment's needs.

############### Config section ###############

#Location where you want backups to go

#SSH configuration

#Number of backups to keep

#Xenserver ssh configuration
#This dictates the address and location of keyfiles as they reside on the xenserver

#E-mail configuration
EMAIL_SUBJECT="`hostname -s | awk '{print "["toupper($1)"]"}'` VM Backup Report: `date +"%A %b %d %Y"`"

########## End of Config section ###############


#Replace any spaces found with backslashes because dd doesn't like them
BACKUP_PATH_ESCAPED="`echo $BACKUP_PATH | sed 's/ /\\\ /g'`"

# SSH command
remote_exec() {
chmod 0600 $XEN_KEY_LOCATION
ssh -i $XEN_KEY_LOCATION -o "StrictHostKeyChecking no" -c $SSH_CIPHER $XEN_USER@$XEN_ADDRESS $1

backup() {
echo "======================================================"
echo "VM Backup started: `date`"
begin="$(date +%s)"
echo "Backup location: ${BACKUP_PATH}"

#add a slash to the end of the backup path if it doesn't exist
if [[ "$BACKUP_PATH" != */ ]]; then

#Build array of VM names
VMNAMES=$(remote_exec "xe vm-list is-control-domain=false | grep name-label | cut -d ':' -f 2 | tr -d ' '")

echo "======================================================"
echo "$VMNAME backup started `date`"
before="$(date +%s)"

# create snapshot
TIMESTAMP=`date '+%Y%m%d-%H%M%S'`
SNAPUUID=$(remote_exec "xe vm-snapshot vm=\"$VMNAME\" new-name-label=\"$SNAPNAME\"")

# export snapshot
# remote_exec "xe snapshot-export-to-template snapshot-uuid=$SNAPUUID filename= | gzip" | gunzip | dd of="$BACKUP_PATH/$SNAPNAME.xva"
remote_exec "xe snapshot-export-to-template snapshot-uuid=$SNAPUUID filename=" | dd of="$BACKUP_PATH/$SNAPNAME.xva"

#if export was unsuccessful, return error
if [ $? -ne 0 ]; then
echo "Failed to export snapshot name = $snapshot_name$backup_ext"

#calculate backup time, print results
after="$(date +%s)"
elapsed=`bc -l <<< "$after-$before"`
elapsedMin=`bc -l <<< "$elapsed/60"`
echo "Snapshot of $VMNAME saved to $SNAPNAME.xva"
echo "Backup completed in `echo $(printf %.2f $elapsedMin)` minutes"

# destroy snapshot
remote_exec "xe snapshot-uninstall force=true snapshot-uuid=$SNAPUUID"

#remove old backups (uses num_backups variable from top)
BACKUP_COUNT=$(find $BACKUP_PATH -name "$VMNAME*.xva" | wc -l)

if [[ "$BACKUP_COUNT" -gt "$NUM_BACKUPS" ]]; then

OLDEST_BACKUP=$(find $BACKUP_PATH -name "$VMNAME*" -print0 | xargs -0 ls -tr | head -n 1)
echo "Removing oldest backup: $OLDEST_BACKUP"
if [ $? -ne 0 ]; then
echo "Failed to remove $OLDEST_BACKUP"
echo "======================================================"

end=$"$(date +%s)"
total_time=`bc -l <<< "$end-$begin"`
total_time_min=`bc -l <<< "$total_time/60"`
echo "Backup completed: `date`"
echo "VM Backup completed in `echo $(printf %.2f $total_time_min)` minutes"

#Run the backup function and save all output to a variable, including stderr
BACKUP_OUTPUT=$(backup 2>&1)

#Clean up the output of the backup function
#Remove records count from dd, do some basic math to make dd's numbers more human readable
BACKUP_OUTPUT_HUMANIZED=$(echo "$BACKUP_OUTPUT" | sed -r '/.*records /d' | tr -d '()' \
| awk '{sub(/.*bytes /, $1/1024/1024/1024" GB "); sub(/in .* secs/, "in "$5/60" mins "); sub(/mins .*/, "mins (" $7/1024/1024" MB/sec)"); print}')

#Send a report e-mail with the backup results

exit $ret_code