Page validation error while reading sas dataset

[nshukla11]

A critical sas dataset got damaged sometime this week. Process has been running for years without issues. I don't have backup of this dataset. Any idea how this can be fixed. 

sas version used is SAS (r) Proprietary Software 9.4 (TS1M2)

Dataset resides in NetApp NFS file system. Any help will be highly appreciated. 

ERROR: Expecting page 4913, got page -1 instead.
ERROR: Page validation error while reading *.*.DATA.
ERROR: File *.*.DATA is damaged. I/O processing did not complete.
NOTE: The SAS System stopped processing this step because of errors.

[Patrick]

Take a binary copy of the damaged dataset, verify that you've got sufficient free disk space in the place where you want to repair your SAS file, then follow Repairing Damage to SAS Data Sets and Catalogs

From what you describe I'd try Proc Datasets/Repair ...but not convinced that it will help.

Even though you haven't taken a backup it might still be worth to contact your SAS admin or IT department. There are hopefully backup and recovery processes in place for the whole filesystem. 

[nshukla11]

Thanks for the inputs. I tried repair before reaching out to community but no luck. And yes, exploring options to recover from filesystem backups.

[Kurt_Bremser]

You have a CRITICAL dataset kept FOR YEARS WITHOUT A BACKUP???

What kind of asylum is this?

Anyway, even if you manage to repair the dataset so it becomes usable again, DO NOT USE IT, as information has been lost already. You need to recreate it from scratch by repeating its evolution from the start.

[nshukla11]

Thanks for your inputs, we are trying to recover the dataset from backed up filesystem. We do not specifically back up sas dataset but we might be able to find old version in filesystem backups, which we are exploring.
When you say - "DO NOT USE IT, as information has been lost already" - so you mean we can never be sure of getting entire data back ? Any idea what might be the root cause of this ?
fyi - I am able to read some not all the records (total =38786605(proc content works) and I can read 4460053 before it fails with error)

[Kurt_Bremser]

All that the REPAIR can do is to adapt the header information to the actual filesize, but it can not make missing dataset pages reappear out of the blue. 

[nshukla11]

Ultimately, restoring the dataset using filesystem backups was the solution. Nothing else worked. Thanks all for valuable inputs.