I would try to dd empty or random data over it or test with virtual
machines where one can remove HDDs from the VM.
thanks, offline the specified drive did the trick and when i re-online the raid drive , it throw the error as expected.
but there is a problem when i restart the machine folder on the root (name as pool name) of file system can b found however zfs partition is not mounted.
i have to run "zfs mount -a" to remount the partition. what can be done to mount the zfs partition on boot.
i know running this command /etc/rc.local would probably work but do you guys think is it a work around or proper way to mount the zfs on boot.
one more issue that i have found. i had smaller files 2 GB each. which i replace by 4GB files so that i could test if i need to increase the size of storage at some time later. eventually all the files has been replace with new one successfully however when i pass the command "df -h" it showed me the old partition size.