We are currently running z/VM 5.4 at 801 CPLEVEL. We have 12 Linux servers running Red Hat. Once a week, we use DFDSS on the z/OS side (z/OS 1.9) to flash copy all the z/VM disks and then copy the flash copied volumes to tape. This process had been working fine for 18 months. We never put any maintenance on z/VM side, but a lot of maintenance had been applied to the z/Linux Servers. About a month ago, we started getting a read only disk error on the z/Linux disk whenever we ran the flash copy. We then wrote scripts to shutdown all the z/Linux servers before doing the flash copy, which only takes about 17 seconds, but the problem still persists.
Does anybody have any idea? Thanks,
