Logs show error 824, logical consistency-based I/O error, incorrect checksum, on reads of one database. Occasionally an 823 appears too. Application errors are intermittent. How bad is this and what is the response?
How to resolve MS SQL error 824 logical consistency I/O error?
Solved SQL & Databases
MS
Michael Scofield July 16, 2019
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Bad. 823 and 824 mean the storage returned different bytes than SQL Server wrote. This is hardware level corruption surfacing through the database.
1
Run
DBCC CHECKDB WITH NO_INFOMSGS, ALL_ERRORMSGS now to map the damage, and check msdb.dbo.suspect_pages for the page list.2
Few damaged pages plus clean backups: page level restore fixes them online with minimal disruption.
3
In parallel get storage checked: disk SMART status, RAID controller logs, cache battery. Fixing pages on dying storage just schedules the next incident.
4
Widespread damage with no clean backup: SysTools SQL Recovery extracts what remains from the MDF before the hardware finishes the job.
3 suspect pages restored from backup and the RAID controller had a failing cache battery. Storage swapped. Solved.