FreeBSD VMWare virtual machine - zpool CKSUM counter keeps growing with over 10K errors per day. Sometimes get permanent damaged files with error 122.
Noticed on 3 systems with high I/O load so far. One of them is FreeBSD 10.1, the other 2 are FreeBSD 10.3.
Issue is reproduced on both local and iSCSI storage. It also reproduces with disk is attached via RDM (raw device mapping) and even it it's attached via FreeBSD iscsid.
Not sure what causes it, because I have no clear log of ZFS CKSUM errors, but it happens only on system with very high disk load. All underlying storage devices I've tried to migrate the VMs on did not report any disk, or network errors.
Investigation steps taken are described in this forum thread:
Given the setup described in the forum post is seems conceivable
that ZFS temporarily lost access to the disk in which case this could
be related to: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=218954