Lock Server Startup; Ccs File Location - Red Hat GFS 6.0 Administrator's Manual

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11.2.1. Linux Page Caching
For GNBD multipath, do not specify Linux page caching (the
mand). All GNBDs that are part of the pool must run with caching disabled. Data corruption occurs if
the GNBDs are run with caching enabled. Refer to Section 11.1.1 Exporting a GNBD from a Server
for more information about using the

11.2.2. Lock Server Startup

Lock servers can reside on the following types of nodes: dedicated lock server nodes, GFS nodes,
or GNBD server nodes. In any case, a lock server must be running before the GNBD servers can be
started.

11.2.3. CCS File Location

In a GFS cluster configured for GNBD multipath, the location of CCS files for each node depends on
how a node is deployed. If a node is deployed as a dedicated GFS node, its CCS files can reside on a
GNBD, local storage, or FC-attached storage (if available). If a node is deployed as a dedicated GNBD
server, its CCS files must reside on local storage or FC-attached storage. If a node is deployed as a
dedicated lock server, its CCS files must reside on local storage or FC-attached storage. Because lock
servers need to start before GNBD servers can start, a lock server cannot access CCS files through a
GNBD. If a lock server is running on a GFS node, the CCS files for that node must be located on local
storage or FC-attached storage.
If a GNBD server that is exporting CCS files is also exporting GNBDs in multipath mode, it must
export the CCS files as read-only. (Refer to Section 11.1.1 Exporting a GNBD from a Server for more
information about exporting a GNBD as read-only.) Under those circumstances, a GNBD client cannot
use to update its copy of the CCS files. Instead, the CCS files must be updated on a node
ccs_tool
where the CCS files are stored locally or on FC-attached storage.
Note
If FC-attached storage can be shared among nodes, the CCS files can be stored on that shared
storage.
Note
A node with CCS files stored on local storage or FC-attached storage can serve the CCS files to
other nodes in a GFS cluster via
failure. For information about
Table 11-1 summarizes where CCS files can be located according to node deployment. For informa-
tion about using CCS, refer to Chapter 7 Using the Cluster Configuration System.
command for GNBD multipath.
gnbd_export
. However, doing so would introduce a single point of
ccs_servd
, refer to Section 7.5.1 CCA File and Server .
ccs_servd
Chapter 11. Using GNBD
option of the
-c gnbd_export
com-