A systems administrator is investigating a file server that has recently experienced unsuccessful nightly backups. The backup job, which targets an iSCSI LUN, fails intermittently with "I/O error" and "target device not available" messages. During business hours, users have also reported slow file access on the server. Which of the following is the MOST likely cause of these combined issues?
A misconfigured backup job schedule.
Insufficient disk space on the iSCSI LUN.
A failing host bus adapter (HBA) in the file server.
The correct answer is a failing host bus adapter (HBA) in the file server. An HBA is a hardware component that connects a server to a storage network. A failing HBA can cause intermittent connectivity issues to storage targets, leading to I/O errors and the target appearing unavailable, which explains the backup failures. It would also cause general I/O performance degradation on the server, explaining the slow file access reported by users.
Insufficient disk space on the iSCSI LUN is a common reason for backup failures, but it would typically generate a "disk full" error, not an "I/O error" or "target device not available" message, nor would it explain the slow performance on the source server.
A misconfigured backup job schedule might cause the job to fail or not run, but it would not produce hardware-level I/O errors or affect user file access during the day.
Corrupt data on the source volume would likely cause read errors from the source disk during the backup process, not errors indicating the target is unavailable.