Linux based file systems become read-only

Products

• VMware vSphere ESXi

Issue/Introduction

VMware has identified a problem where file systems may become read-only after encountering busy I/O retry or SAN or iSCSI path failover errors.

 

The same behavior is expected even on a native Linux environment, where the time required for the file system to become read-only depends on the number of paths available to a particular target, the multi-path software installed on the operating system, and whether the failing I/O was to an EXT3 Journal. However, the problem is aggravated in an ESX host environment because ESX host manages multiple paths to the storage target and provides a single path to the guest operating system, which effectively reduces the number of retries done by the guest operating system.

 

Most Linux operating system flavors are impacted because of this issue.

Environment

VMware vSphere ESXi 

Resolution

VMware recommends consulting the Guest Operating system vendor for fixes to mitigate the read only file system issue.

As a workaround, remount the Linux file system using this command to return it to the proper state:
 

mount -o remount /

Note: It is ideal to identify the problem and resolve the issue rather than performing this workaround when this situation arises.