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.