HP Storage Mirroring Software User Manual

Page 14

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Storage Mirroring Data Migration requirements

Page 13 of 135

3. If you select a dynamic volume and you increase the size of the volume, the target

must be able to compensate for an increase in the size of the dynamic volume.

4. If you select files with alternate data streams, keep in mind the following.

a. Alternate data streams are not included in the replication set size calculation.

Therefore, you may see the mirror process at 100% complete while mirroring
continues.

b. The number of files and directories reported to be mirrored will be incorrect. It

will be off by the number of alternate streams contained in the files and
directories because the alternate streams are not counted. This is a reporting
issue only. The streams will be mirrored correctly.

c. Use the checksum option when performing a difference mirror or verification

to ensure that all alternate data streams are compared correctly.

d. If your alternate streams are read-only, the times may be flagged as different

if you are creating a verification report only. Initiating a remirror with the
verification will correct this issue.

5. If you select encrypted files, 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 Data Migration 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.

f. Empty encrypted files will be mirrored to the target, but if you copy or create

an empty encrypted file within the replication set after mirroring is complete,
the empty file will not be created on the target. As data is added to the empty
file on the source, it will then be replicated to the target.

g. When you are replicating encrypted files, a temporary file is created on both

the source and target servers. The temporary file is automatically created in
the same directory as the Storage Mirroring Data Migration disk queues. If
there is not enough room to create the temporary file, an out of disk space
message will be logged. This message may be misleading and indicate that

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