A larger computational cluster – Apple Xsan 1.x User Manual
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Chapter 3
Deployment Examples
Which LUNs go in each storage pool?
For metadata, we use a single 2-drive RAID 1 array. For the data pools, we can use the
RAID 5 LUNs available straight out of the box on the Xserve RAID systems: one on the
system that also supports the metadata and two on each of the other Xserve RAID
systems for a total of 5.
Which clients should be able to access each volume?
All clients (processing nodes) have access to the data volume.
Which computers will act as controllers?
There is a dedicated metadata controller.
Do you need standby controllers?
Yes, one.
Do you want to use controllers as clients also?
The metadata controllers are dedicated to that task and will not function as clients.
Where do you want to store file system metadata and journal data?
For the sake of performance, metadata and journal data are stored on a separate LUN
dedicated for that purpose.
A Larger Computational Cluster
A cluster consisting of more than 64 nodes requires a different configuration (similar to
NAS) because Xsan is limited to 64 Fibre Channel devices (controllers, clients, and
storage devices) in a SAN.
1
3
4
5
6
2
2-disk RAID 1
1
6-disk RAID 5
2
6-disk RAID 5
3
6-disk RAID 5
4
6-disk RAID 5
5
6-disk RAID 5
6
Out data pool w/affinity for results
Metadata pool
In data pool w/affinity for source