Cant access volume

Hello,

We are using an 8-engine VMAX 40K storage to host our open systems and provide storage to different company groups.
This storage has no backup at all, and the RAID levels in use are RAID 5 and RAID 6.

Some time ago, due to the cache becoming full, we were forced to power off and power on the storage to see whether the issue would be resolved and the cache would be cleared, but that did not help. We then replaced a director and performed multiple troubleshooting steps, none of which solved the problem.

Eventually, we had to run the Vault Recovery procedure, which partially worked and made the data accessible again. However, over time, the cache filled up again.
We then had to replace a failed disk, based on “data lost” messages reported by the storage, but this did not resolve the issue either.

After that, the cache capacity was reduced by about half, as if those disks caused some of the cached data to be lost. The cache never fully dropped to zero, and the same issue continued.
Later, we replaced two more disks, again based on data lost messages, and after that the cache stopped decreasing.

Finally, we executed the inline cache background procedures using specific commands, and now the situation is as follows:

• The volumes are allocated and presented to the hosts

• But on the hosts, the data is not visible

• In Disk Management, the volumes appear as RAW

It seems that some tables or metadata structures may be missing or corrupted.

Does anyone have a solution or recommendation for this situation?