Internal disks for vPar

[Mad_1]

I would like to ask a question about vPar.

For rp74xx or rp84xx, there are only 4 internal disks. If several vPar (let's say 8) are required to configured, how can the internal disks be distributed to each vPar? Where is each OS of vPar be installed?

[Stefan Stechemesser · Accepted solution]

For vpars you have to assign I/O recources to each partition, but unfortunately you can only assign complete PCI busses (on this type of machines each PCI bus contains only one card) to each partition. Because the internal disks are hanging on the core I/O card(s), that are hanging for each cell board on different PCI busses, you can assign your internal disks to max. 2 virtual/hard partitions.
If you want to run 8 vpars, you have to buy at least 6 separate bootdisks on 6 separate SCSI cards (double port cards will not help, because then the busses are on one PCI bus). However you could use lan/scsi combo cards to save some I/O slots (you have 14 in your machines).

I hope this helps

Stefan

[Ted Buis]

For the rp74xx, while you can use combo SCSI/LAN PCI cards to provide the required boot paths and LAN (both required), you cannot have more vPars than CPUs. Also, consider that memory must be allocated to each partition and cannot (at present) float between partitions. Since HP recommends 2GB of RAM with a minumum of 512MBfor 11i), you also need to make sure you have 4GB to 16GB or RAM for 8 vPars. External DS2100 or DS2110 storage enclosures could be used for the disks. The hold four hot plug disks in a 1U enclosure, and you can split the SCSI bus if desired (not an HA solution).

[Mad_1]

As there are 2 cell boards within rp7410, and 2 hard partitions can be configured as 2 separate servers.

But I suspect that there should be some hardware connection (e.g. backplane or main controller,..) between 2 cell boards. That means there may be single point of failure that cause 2 separate nPar down. is it correct?

[Ted Buis]

There is a 45 page pdf on the rp7410 from a technical perespective at http://www.hp.com/products1/servers/rackoptimized/rp7410/infolibrary/rp7410_wp.pdf
In it it says the rp7410 has, "protection against hardware errors in the same nodeâ most hardware errors in the same node will not bring down a peer partition in the same node". Also, "Special programmable hardware in the cells defines the boundaries of a partition in such a way that isolation from the actions of other partitions is enforced."
So there is hardware isolation between cells, but if this isolation hardware failed, one might consider that a SPOF, but it might take a double failure to notice that the hardware isolation wasn't there. Main point is that nPars provides more isolation than vPars but has less flexibility as they are only divide the system at cell boundari