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.
These guest operating systems are affected:
- RHEL5 (RedHat)
- RHEL4 U6
- RHEL4 U4
- RHEL4 U3
- SLES10
- SLES9 SP3
- Ubuntu 7.04
Note: This issue may affect other Linux distributions based on early 2.6 kernels as well, such as Ubuntu 7.04.