HP StorageWorks Clustered File System 3.6.0 Windows Storage Server Edition (software-only) Release Notes (432086-004, February 2008)

• If you restore data from an NTFS filesystem to a PSFS filesystem, you may see warnings such as
the
following. The warnings indicate that da ta belonging to an unsupported NTFS feature will
be lost during the restore.
Warning: The target file system does not support some of the
features of the original filesystem. Some data may not be restored
as a result. Warning: Unable to set the short 8.3 name for
“V:\test-restore\WINNT\q50.dmp.gz”. Reason: The parameter is
incorrect.
Filesystem semantics
The PSFS fi lesystem differs sema ntically from the NTFS filesystem in the following ways:
• A file cannot be deleted if it is currently open on another node.
• A file cannot b
e
“renamed over” if it is currently open on another node. For example, an attempt
to
rename filea to fileb willfailif fileb is currently op en on another node.
• The time that a file was last accessed is not updated af ter a successful read operation, even on
the
local no
de.
• When a directory is renamed, subsequent change notify requests within that directory are not
completed. For example, if Windows Explorer is open at a certain directory on the loc a l node
and that directory is renamed on a remote node, any subsequent changes to the renamed
directory
will not appear in the local Explorer window. You will need to close and reopen
Explorer to see the renamed directory.
• Memory-mapped files are not coherent across nodes. B ecause PSFS is a shared filesystem,
the
same fi
le can
be map ped into memory on more than one node. When a change is made
to a
file on
aremotenode, thelocal node does notsee thechange immediately. This occurs
because the operating system on the remote node may not immediately write the change to disk.
Consequently, PSFS allows writes to files that are being executed on other nodes.
• If the Bypass Traverse Checking privilege is not enabled, differences in traverse a ccess checking
for Directory Change N otification (DCN) may be observed. On NTFS, before a change notify
request is completed, an access check is performed to d etermine whether the subscriber has
traver
se access to the directory in which the contents were m o d ified. If the subscriber does not
have traverse access, the change notification will not be delivered.
• On PSFS, this check is not performed and the contents of directories (e.g., the names of files)
may be
exposed via DCN to a user who would otherwise not obtain this data. Traverse access
checking other than during directory change notification is as expected, so access to file contents
is notcompromised. Theuserisadvised nottodependontraverseaccesscheckingto protect
sensitive data that is encoded in the names of files or directori es. Instead, the user should place
sens
itive data in files and s hould rely on file security descriptors to deny access to the files’
contents by unauthorized users.
Windows utilities and services
The following Windows utilities differ in operation on NTFS and PSFS filesystems:
• Disk checks—In both Windows Explorer and the Disk Management utility, you can right-click a
disk volume to see its properties. The Tools tab on the Properties window includes an option to
check the disk volume for errors. This option cannot be used with PSFS filesy stems. Also, the
command line
chkdsk utility cannot be used to check for errors. In place of these utilities, use the
HP Clustered File SystemGateway psfscheck utility to check the disk. See the HP StorageWorks
Clustered File System 3.4.0 Window Storage Server Edition administration guidefor details
about the utility.
• Remote Storage Service—Because PSF S filesystems do not support reparse points representing
offline files, the Remote Storage Service might not operate correctly. If the cluster has a la rge
number of disks, you may see error messages generated from this service. If you do not n ee d the
Remote Storage Service, it can be disabled in the Services Control Panel applet.
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