Abstract: A filesystem conversion process converts a filesystem from one implementation type to another type while the filesystem remains active and fully accessible. The conversion process builds a list of directories in the filesystem that are of the old filesystem type and then converts each directory until the entire filesystem is converted. Instead of the filesystem being shutdown to perform the conversion, the conversion process may run as a background thread that does not interfere with normal filesystem operations.

Abstract: An apparatus and method provides the capability of mirroring storage between geographically remote locations in an asynchronous manner that does not require all writes on primary storage to be performed in the same order on the mirrored storage. The mirroring of the present invention is “logical mirroring”, which does not require identical disk drives, and which supports mirroring between geographically remote locations to protect against catastrophic site failure. A sequence number is assigned to data written to primary storage before the data is transferred to the mirrored storage. The mirrored storage can write data asynchronously, which may result in some data being written before previous data on the mirrored storage. When a system failure occurs that requires use of the mirrored storage, the mirrored storage is first quiesced to allow all pending writes to occur.