2www.redhat.com
ADD;ONS FOR RED HAT ENTERPRISE LINUX 61&2&3!442
567")"60+%3+89(#6%&--./0%
5HG+DWV5HVLOLHQW6WRUDJH$GG2QHQDEOHVDVKDUHGVWRUDJHRUFOXVWHUHGoOHV\VWHPWRDFFHVV
the same storage device over a network. By providing consistent storage across a cluster of
servers, Red Hat’s Resilient Storage Add;On creates a pool of
data that is available to each server in the group, but which
also is protected if any one server fails.
7KH5HVLOLHQW6WRUDJH$GG2QSURYLGHVQXPHURXVoOHV\VWHP
capabilities for improving resiliency to system failure. This
add;on includes the Global File System 2 (GFS2) for supporting
FRQFXUUHQWDFFHVVD3RUWDEOH2SHUDWLQJ6\VWHP,QWHUIDFHIRU81,;326,;FRPSOLDQWoOHV\V;
WHPDFURVVQRGHVDQG&OXVWHUHG6DPEDDFOXVWHUHGFRPPRQ,QWHUQHWoOHV\VWHPRU&,)6
IRUFRQFXUUHQWoOHVVKDUHVLQD0LFURVRIW:LQGRZVHQYLURQPHQW
:KHQXVLQJWKH5HVLOLHQW6WRUDJH$GG2QDVLQJOHYHUVLRQRIDOOoOHVLQDFOXVWHUDUHYLVLEOHWR
all nodes within that cluster. Each server in a cluster has direct access to a shared block device
over a local storage area network (SAN) of up to 100 terabytes. Data and cache consistency is
ensured using a cluster;wide locking mechanism called distributed lock manager (DLM) to arbi;
trate access to the storage. Each member of the cluster thus has direct access to the same stor;
DJHGHYLFHDQGDOOFOXVWHUQRGHVDFFHVVWKHVDPHVHWRIoOHV
:6+;89<%=8(-%>()(0?69%&--./0
Red Hat’s Network Load Balancer Add;On provides redundancy for web serving, databases, net;
working, and storage. By creating a virtual address that can be directed to a real server for load
EDODQFLQJRUWUDIoFVKDSLQJWKH5HG+DW1HWZRUN/RDG%DODQFHU$GG2QDOORZV\RXWRTXLFNO\
add or remove servers or change balancing algorithms using
a browser;based graphical user interface (GUI).
The Network Load Balancer Add;On provides support for trans;
mission control protocol (TCP) and user datagram protocol
(UDP) load balancing independent of applications. It is com;
posed of two major components: the Linux Virtual Server (LVS)
DQGWKH3LUDQKD&RQoJXUDWLRQ7RROD*8,EDVHGPDQDJHPHQWWRRO7KH1HWZRUN/RDG%DODQFHU
$GG2QFDQEHFRQoJXUHGDFURVVWZRQRGHVLQDQDFWLYHSDVVLYHFRQoJXUDWLRQWRSURYLGHUHGXQ;
GDQWWUDIoFPDQDJHPHQWVHUYLFHV
ADD8ON OPTIONS FOR SCALABILITY
3?()(*)6%@")6%3,7+6A%&--./0
5HG+DWV6FDODEOH)LOH6\VWHP$GG2QSURYLGHVVXSSRUWIRUoOHV\VWHPVWKDWDUHEHWZHHQ
WHUDE\WHVDQGWHUDE\WHVLQVL]H<RXFDQPDQDJHWKHVHODUJHGDWDVWRUHVXVLQJ
advanced features such as 64;bit journaling and advanced
locking algorithms.
The Scalable File System Add;On uses the XFS®oOHV\VWHP
ZKLFKLQDGGLWLRQWRVXSSRUWLQJYHU\ODUJHoOHVDQGoOHV\VWHPV
on a single host, also performs well on smaller systems run;
QLQJPXOWLWKUHDGHGSDUDOOHO,2ZRUNORDGV
