> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cockroachlabs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Technical Advisory 48860

export const InternalLink = ({version, path = "", children, ...props}) => {
  let detectedVersion = version || "stable";
  if (typeof window !== 'undefined' && !version) {
    const match = window.location.pathname.match(/\/docs\/([^/]+)/);
    if (match) {
      detectedVersion = match[1];
    }
  }
  const normalizedPath = path.startsWith("/") ? path.slice(1) : path;
  return <a href={`/docs/${detectedVersion}/${normalizedPath}`} {...props}>
      {children}
    </a>;
};

Publication date: May 20, 2020

## Description

Range deletions (as caused by certain [table drops](https://www.cockroachlabs.com/docs/v20.1/drop-table), [table truncates](https://www.cockroachlabs.com/docs/v20.1/truncate), and certain rebalancing operations during [node decommissioning](https://www.cockroachlabs.com/docs/v20.1/remove-nodes) or failover), when occurring concurrently with replica [garbage collection](https://www.cockroachlabs.com/docs/v20.1/architecture/storage-layer#garbage-collection), can yield permanent data corruption or loss in rare cases.

## Statement

A defect in RocksDB allowed it to violate its guarantees for snapshots, causing corruption under specific and extremely rare circumstances. This corruption is irrecoverable using regular node failover and must be addressed by restoring a backup when it occurs.

This bug has been fixed in versions v19.1.9, v19.2.7, and v20.1.0. All users are encouraged to upgrade (see [Mitigation](#mitigation) below).

## Mitigation

There is no mitigation possible without an upgrade. Cockroach Labs recommends that customers upgrade to the latest release of [v19.1](https://www.cockroachlabs.com/docs/v19.1/upgrade-cockroach-version), [v19.2](https://www.cockroachlabs.com/docs/v19.2/upgrade-cockroach-version), or [v20.1](https://www.cockroachlabs.com/docs/v20.1/upgrade-cockroach-version), all of which are currently under <InternalLink version="releases" path="release-support-policy">Maintenance Support</InternalLink>.

Because CockroachDB v2.1 will reach <InternalLink version="releases" path="release-support-policy">unsupported</InternalLink> on July 1, 2020, no new maintenance release for v2.1 will be issued containing a fix for this bug. Affected deployments running v2.1 should be upgraded to at least the latest release of [v19.1](https://www.cockroachlabs.com/docs/v19.1/upgrade-cockroach-version).

## Impact

All CockroachDB v2.x and v19.x releases up to and including v19.1.8 and v19.2.6 are affected. When encountered, the bug causes data corruption or loss.

Questions about any technical alert can be directed to our [support team](https://support.cockroachlabs.com/).