HP StorageWorks Storage Mirroring for Linux User's Guide (T2558-96078, February 2008)

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 If a soft link to a directory is part of a replication set rule’s path above the entry point to the replication set data, that
link will be created on the target as a regular directory if it must be created as part of the target path.
 If a soft link exists in a replication set (or is moved into a replication set) and points to a file or directory inside the
replication set, Storage Mirroring will remap the path contained in that link based on the Storage Mirroring target
path when the option RemapLink is set to the default value (1). If RemapLink is set to zero (0), the path contained
in the link will retain its original mapping.
 If a soft link exists in a replication set (or is moved into a replication set) and points to a file or directory outside the
replication set, the path contained in that link will retain its original mapping and is not affected by the RemapLink
option.
 If a soft link is moved out of or deleted from a replication set on the source, that link will be deleted from the target.
 If a soft link to a file is copied into a replication set on the source and the operating system copies the file that the
link pointed to rather than the link itself, then Storage Mirroring replicates the file copied by the operating system to
the target. If the operating system does not follow the link, only the link is copied.
 If a soft link to a directory is copied into a replication set on the source and the operating system copies the directory
and all of its contents that the link pointed to rather than the link itself, then Storage Mirroring replicates the
directory and its contents copied by the operating system to the target. If the operating system does not follow the
link, only the link is copied.
 If any operating system commands, such as chmod or chown, is directed at a soft link on the source and the
operating system redirects the action to the file or directory which the link references, then if the file or directory
referenced by the link is in a replication set, the operation will be replicated for that file to the target.
 The operating system redirects all writes to soft links to the file referenced by the link. Therefore, if the file
referenced by the symbolic link is in a replication set, the write operation will be replicated to the target.
 If you are using hard links, keep in mind the following.
 If a hard link exists (or is created) only inside the replication set on the source, having no locations outside the
replication set, the linked file will be mirrored to the target for all locations and those locations will be linked if all
link locations on the target exist on the same partition.
 If a hard link crosses the boundaries of a replication set on the source, having locations both inside and outside the
replication set, the linked file will be mirrored to the target for only those locations inside the replication set on the
source, and those locations will be linked on the target if all link locations exist on the same partition.
 If a hard link is created on the source linking a file outside the replication set to a location inside the replication set,
the linked file will be created on the target in the location defined by the link inside the replication set and will be
linked to any other locations for that file which exist inside the replication set.
 If any hard link location is moved from outside the replication set into the replication set on the source, the link will
not be replicated to the target even if other link locations already exist inside the replication set, but the linked file
will be created on the target in the location defined by the link.
 If any hard link location existing inside the replication set is moved within the replication set on the source, the move
will be replicated to the target and the link will be maintained if the new link location does not cross partitions in the
target path.
 If any hard link location existing inside the replication set is moved out of the replication set, that file or linked location
will be deleted on the target.
 If a hard linked file is copied from any location inside or outside the replication set to a location inside the replication
set on the source, the copy will be replicated to the target.
 If a hard linked file has a location in the replication set and any of the operating system commands, such as chmod
or chown, are directed at that file from a location inside the replication set, the modification to the file will be
replicated to the target. Operations on hard links outside of the replication set are not replicated.
 If a hard linked file has a location in the replication set and a write operation is directed at that file from inside the
replication set, the write operation will be replicated to the target. Opertions on hardl inks outside of the replication
set are not replicated.
 If any hard link location existing inside the replication set is deleted on the source, that file or linked location will be
deleted from the target.
 If a hard link location is created on the same volume but outside of the path where DTFS is mounted, the hard link
operation will fail because the operating system regards the DTFS mount as a separate volume.
Multi-Client Access
Replication sets contain error checking to avoid inadvertent overwrites of the replication set database file. When it is retrieved
from the source to the client, a generation number is associated with the retrieval. The generation number is incremented
anytime there are successful changes to it. When attempting to save a replication set, the generation numbers on the source
and client are compared and if they are different, the save is not allowed. The Storage Mirroring Management Console will
prompt you if the replication set cannot be saved. This error checking safeguards the replication set data in the event that
more than one client machine is accessing the source machine’s replication sets.