RHEL5, RHEL4 U4, RHEL4 U3, SLES10, and SLES9 SP3 File Systems may Become Read-Only
Details
VMware has identified a problem with RHEL5, RHEL4 U4, RHEL4 U3, SLES10, and SLES9 SP3 guest operating systems. Their file systems may becomeread-only in the event of busy I/O retry or path failover of the ESX Server's SAN or iSCSI storage.
This issue may affect other Linux distributions based on early 2.6 kernels as well, such as Ubuntu 7.04
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 Server environment because ESX Server 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.
