HP Storage Mirroring Software - Manual (Page 50)

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Replication Capabilities
Storage Mirroring replicates all file and directory data stored on any Windows file system (FAT, FAT32, NTFS4, and NTFS5).
Replicated items also include Macintosh
®
files, compressed files, NTFS attributes and ACLs, dynamic volumes, and sparse files.
Files can be replicated across mount points, even though mount points are not created on the target.
Storage Mirroring does not replicate items that are not stored on the file system, such as physical volume data and registry
based data. By default, system volume information, if included in the replication set, will be mirrored and replicated, although
it is recommended that this type of data not be included in the replication set. The %systemroot%, usually c:\winnt, is not
mirrored or replicated, by default. Addtionally, Storage Mirroring does not replicate NTFS extended attributes, registry hive
files, Windows or any system or driver pagefile, and system metadata files ($LogFile, $Mft, $BitMap, $Extend\\$UsnJrnl,
$Extend\\$Quota, $Extend\\$ObjId, and $Extend\\$Reparse).
In addition, note the following information:
1. If you select a Windows 200x mount point, by default, the mount point data will be stored in a directory on the target
machine. You can create a mount point on the target to store the data or maintain the replicated data in a directory. If
you use a directory, it must be able to handle the amount of data contained in the mount point.
2. If you select a Windows 200x dynamic volume and you increase the size of the volume, the target machine must be able
to compensate for an increase in the size of the dynamic volume.
3. If you select Windows 200x hard links for replication, the links will be created as files on the target. If the link is outside
of the replication set, you could lose data if you have to restore after a failure.
4. If you select data stored on a recursive mount point for replication, a mirror will never finish. Storage Mirroring does
not check for data stored on recursive mount points.
5. Reparse points are not replicated by Storage Mirroring.
6. Remove Storage files can be mirrored and replicated, but because of the way they are handled by Windows 200x, the
server may be tied up for extended periods of time while it attempts to stream the migrated data back to disk while
mirroring. You can configure Storage Mirroring and other backup applications to ignore migrated files, by setting the
SkipFilesForLegacyBackup registry setting. See your Microsoft reference manual for more information.
7. If you are using alternate data streams, they are not included in the replication set size calculation. Therefore, you may
see the mirror process at 100% complete while mirroring continues.
8. If you select Windows 200x encrypted files for replication, keep in mind the following:
a. Only the data, not the attributes or security/ownership, is replicated. However, the encryption key is included. This
means that only the person who created the encrypted file on the source will have access to it on the target.
b. Only data changes cause replication to occur; changing security/ownership or attributes does not.
c. Replication will not occur until the Windows Cache Manager has released the file. This may take awhile, but
replication will occur when Storage Mirroring can access the file.
d. When remirroring, the entire file is transmitted every time, regardless of the remirror settings.
e. Verification cannot check encrypted files because of the encryption. If remirror is selected, the entire encrypted file
will be remirrored to the target. Independent of the remirror option, all encrypted files will be identified in the
verification log.
9. If you have a FAT volume on the source, mounted on a directory which resides on an NTFS volume, also on the source,
these files will not be mirrored, regardless of the target file system. Replication will work correctly. To work around this
issue, make sure both volumes are NTFS.
10. If you select a compressed file or folder from an NTFS partition and replicate it to FAT target, the attributes are lost but
the data is maintained.
11. If you are mirroring/replicating from an NTFS source to a FAT target, you may see additional error messages in your
Storage Mirroring log file because the target file system cannot handle the NTFS attributes or file permissions. Here are
two examples:
a. Alternate Data Streams—If your replication set contains files with alternate data streams, you will see messages
indicating that there are unfinished operations because the FAT file system cannot store the alternate, or the default,
data stream information.
b. Encrypted files—If your replication set contains encrypted files, the files will not be replicated. They will exist on the
target as zero byte files (
0 KB) and the Storage Mirroring log will report that the files are not backed up.
NOTE: If any directory or file contained in your replication set specifically denies permission to the system account or
the account running the Storage Mirroring service, the attributes of the file on the target will not be updated
because of the lack of access. This also includes denying premission to the Everyone group because this group
contains the system account.