The Apache Foundation had a security breach a few days ago (no, not on the Solaris 10 system ), that led to the compromitation of their services. A nice information was the role that ZFS played in the recovery of this situation. The Infastructure Team wrote in their article about the recovery:
aurora.apache.org runs Solaris 10, and we were able to restore the box to a known-good configuration by cloning and promoting a ZFS snapshot from a day before the CGI scripts were synced over. Doing so enabled us to bring the EU server back online, and to rapidly restore our main websites. Thereafter, we continued to analyze the cause of the breach, the method of access, and which, if any, other machines had been compromised.
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