We've been able to start 200 guest domains under
SLES10 and Xen Unstable. In one test we successfully started 200
hardware-virtualized Win2003 domains, and in a separate test we successfully
started 200 para-virtualized SLES10 domains. In both tests, after 200 guests,
the host system became unresponsive - no errors were displayed on the
serial console, and 'top' and 'xm top' sessions showed that sufficient memory
was still available.
In these tests, Xen Unstable was built with
NR_DYNIRQS = 1024, and the system was booted with dom0_mem=512M and
xenheap_megabytes=64. Guests were each stored on separate luns on san storage,
and booted via physical block device (phy:). No workload was run in the
guests.
Host Platform Hardware:
ES7000/0ne (2-cell configuration) with 16 cpus (8 dual-core sockets,
non-hyperthreaded)
64gb memory
SAS
internal RAID boot disks
2 Emulex lp1005
HBAs.
Host Platform Software:
SLES10
Xen Unstable tree (changeset
13541)
Code deviations from changeset: NR_DYNIRQS set to
1024 in
./linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/irq_vectors.h
Additional Xen Boot Options: dom0_mem=512M,
xenheap_megabytes=64
Storage Subsystem:
Unisys
Clariion EMC CX600, 30 disk spindles @ 36GB 15Krpm configured as 200 4.5GB RAID5
volumes
Hardware-Virtualized Test:
Guest domains: Win2003 Server Std Edition, 256mb memory, 1 vcpu, OS on single
external physical lun, dhcp
Para-Virtualized Test:
Guest
domains: SLES10, 96mb memory, 4 vcpu, OS on single external physical lun, fixed
IP