[CentOS] how to optimize CentOS XEN dom0?

Tue Feb 22 23:41:58 UTC 2011
Ian Murray <murrayie at yahoo.co.uk>

Are they paravirt of HVM guests? qemu might have something to do with it if HVM 
guests are involved.




----- Original Message ----
> From: Rudi Ahlers <Rudi at SoftDux.com>
> To: CentOS mailing list <centos at centos.org>
> Sent: Tue, 22 February, 2011 23:29:29
> Subject: [CentOS] how to optimize CentOS XEN dom0?
> 
> Hi,
> 
> I have a problematic CentOS XEN server and hope someone could point  me
> in the right direction to optimize it a bit.
> 
> The server runs on a  Core2Quad 9300, with 8GB RAM (max motherboard can
> take, 1U chassis) on an  Intel motherboard with a 1TB SATA HDD.
> 
> dom0 is set to 512MB limit with a  few small XEM VM's running:
> 
> 
> root at zaxen01:[~]$ xm list
> Name                                        ID Mem(MiB) VCPUs State    Time(s)
> Domain-0                                    0       512     4 r-----     96.5
> actionco.vm                                  3     1519     1 -b----      14.8
> byracers.vm                                 4       511     1 -b----     85.7
> ns1                                          5      511     1  -b----     22.3
> picturestravel                             6       255     1 -b----     13.3
> rafttheworld                                 7      255     1 -b----      11.3
> zafepres.vm                                 8       511     1 -b----     19.0
> 
> 
> 
> 
> the  server itself seems to eat up a lot of resources:
> 
> 
> root at zaxen01:[~]$  free -m
>              total        used       free     shared    buffers      cached
> Mem:           512         472         39           0         13        215
> -/+  buffers/cache:        244         268
> Swap:         4095           0       4095[/CODE]
> 
> 
> Yet, it only has XEN, Webmin  (since it's a CloudMin XEN server), Exim,
> Apache and a few other services  running:
> 
> 
> 
> root at zaxen01:[~]$ chkconfig --list |grep "3:on" |awk  '{print $1}'  |sort
> acpid
> auditd
> crond
> csf
> dhcpd
> exim
> haldaemon
> httpd
> iptables
> iscsi
> iscsid
> kudzu
> lfd
> lvm2-monitor
> mdmonitor
> network
> qemu
> restorecond
> setroubleshoot
> smartd
> snmpd
> sshd
> syslog
> sysstat
> webmin
> xend
> xendomains
> 
> 
> 
> 
> Is  there anything I can optimize on such a server?
> 
> 
> 
> The server runs  CentOS 5.5 x64:
> 
> root at zaxen01:[~]$ cat /etc/redhat-release
> CentOS  release 5.5 (Final)
> 
> root at zaxen01:[~]$ uname -a
> Linux  zaxen01.softdux.com 2.6.18-194.32.1.el5xen #1 SMP Wed Jan 5
> 18:44:24 EST 2011  x86_64 x86_64 x86_64 GNU/Linux
> 
> with  Xen version  3.1.2-194.32.1.el5
> 
> 
> And there's the xm dmesg output:
> 
> 
> Xen  version 3.1.2-194.32.1.el5 (mockbuild at centos.org) (gcc  version
> 4.1.2 20080704 (Red Hat 4.1.2-48)) Wed Jan  5 17:43:03 EST  2011
>  Latest ChangeSet: unavailable
> 
> (XEN) Command line:  dom0_mem=512M
> (XEN) Video information:
> (XEN)  VGA is text mode 80x25,  font 8x16
> (XEN)  VBE/DDC methods: V2; EDID transfer time: 1  seconds
> (XEN) Disc information:
> (XEN)  Found 1 MBR  signatures
> (XEN)  Found 1 EDD information structures
> (XEN) Xen-e820  RAM map:
> (XEN)  0000000000000000 - 000000000008f000  (usable)
> (XEN)  000000000008f000 - 00000000000a0000  (reserved)
> (XEN)  00000000000e0000 - 0000000000100000  (reserved)
> (XEN)  0000000000100000 - 00000000cf53f000  (usable)
> (XEN)  00000000cf53f000 - 00000000cf54b000  (reserved)
> (XEN)  00000000cf54b000 - 00000000cf620000  (usable)
> (XEN)  00000000cf620000 - 00000000cf6e8000 (ACPI  NVS)
> (XEN)  00000000cf6e8000 - 00000000cf6ec000 (usable)
> (XEN)   00000000cf6ec000 - 00000000cf6f1000 (ACPI data)
> (XEN)  00000000cf6f1000  - 00000000cf6f2000 (usable)
> (XEN)  00000000cf6f2000 - 00000000cf6ff000  (ACPI data)
> (XEN)  00000000cf6ff000 - 00000000cf700000  (usable)
> (XEN)  00000000cf700000 - 00000000d0000000  (reserved)
> (XEN)  00000000fff00000 - 0000000100000000  (reserved)
> (XEN)  0000000100000000 - 0000000230000000 (usable)
> (XEN)  System RAM: 8181MB (8378020kB)
> (XEN) Xen heap: 13MB (13720kB)
> (XEN) Domain  heap initialised: DMA width 32 bits
> (XEN) Processor #0 7:7 APIC version  20
> (XEN) Processor #2 7:7 APIC version 20
> (XEN) Processor #1 7:7 APIC  version 20
> (XEN) Processor #3 7:7 APIC version 20
> (XEN) IOAPIC[0]: apic_id  2, version 32, address 0xfec00000, GSI 0-23
> (XEN) Enabling APIC mode:   Flat.  Using 1 I/O APICs
> (XEN) Using scheduler: SMP Credit Scheduler  (credit)
> (XEN) Detected 2485.797 MHz processor.
> (XEN) HVM: VMX  enabled
> (XEN) VMX: MSR intercept bitmap enabled
> (XEN) I/O virtualisation  disabled
> (XEN) CPU0: Intel(R) Core(TM)2 Quad  CPU   Q9300  @  2.50GHz stepping 07
> (XEN) Booting processor 1/2 eip 90000
> (XEN) CPU1:  Intel(R) Core(TM)2 Quad  CPU   Q9300  @ 2.50GHz stepping  07
> (XEN) Booting processor 2/1 eip 90000
> (XEN) CPU2: Intel(R) Core(TM)2  Quad  CPU   Q9300  @ 2.50GHz stepping 07
> (XEN) Booting  processor 3/3 eip 90000
> (XEN) CPU3: Intel(R) Core(TM)2 Quad  CPU    Q9300  @ 2.50GHz stepping 07
> (XEN) Total of 4 processors  activated.
> (XEN) ENABLING IO-APIC IRQs
> (XEN)  -> Using new ACK  method
> (XEN) Platform timer overflows in 2 jiffies.
> (XEN) Platform timer  is 1.193MHz PIT
> (XEN) Brought up 4 CPUs
> (XEN) *** LOADING DOMAIN 0  ***
> (XEN) elf_parse_binary: phdr: paddr=0xffffffff80200000  memsz=0x2f4d70
> (XEN) elf_parse_binary: phdr: paddr=0xffffffff804f4d80  memsz=0x14c510
> (XEN) elf_parse_binary: phdr: paddr=0xffffffff80642000  memsz=0xc08
> (XEN) elf_parse_binary: phdr: paddr=0xffffffff80644000  memsz=0x11be8c
> (XEN) elf_parse_binary: memory: 0xffffffff80200000 ->  0xffffffff8075fe8c
> (XEN) elf_xen_parse_note: GUEST_OS = "linux"
> (XEN)  elf_xen_parse_note: GUEST_VERSION = "2.6"
> (XEN) elf_xen_parse_note:  XEN_VERSION = "xen-3.0"
> (XEN) elf_xen_parse_note: VIRT_BASE =  0xffffffff80000000
> (XEN) elf_xen_parse_note: PADDR_OFFSET =  0xffffffff80000000
> (XEN) elf_xen_parse_note: ENTRY =  0xffffffff80200000
> (XEN) elf_xen_parse_note: HYPERCALL_PAGE =  0xffffffff80206000
> (XEN) elf_xen_parse_note: FEATURES  =
>"writable_page_tables|writable_descriptor_tables|auto_translated_physmap|pae_pgdir_above_4gb|supervisor_mode_k
>k
> ernel"
> (XEN)  elf_xen_parse_note: LOADER = "generic"
> (XEN) elf_xen_addr_calc_check:  addresses:
> (XEN)     virt_base        =  0xffffffff80000000
> (XEN)     elf_paddr_offset =  0xffffffff80000000
> (XEN)     virt_offset      =  0x0
> (XEN)     virt_kstart      =  0xffffffff80200000
> (XEN)     virt_kend        =  0xffffffff8075fe8c
> (XEN)     virt_entry       =  0xffffffff80200000
> (XEN)  Xen  kernel: 64-bit, lsb,  compat32
> (XEN)  Dom0 kernel: 64-bit, lsb, paddr 0xffffffff80200000 ->  
>0xffffffff8075fe8c
> (XEN) PHYSICAL MEMORY ARRANGEMENT:
> (XEN)  Dom0  alloc.:   0000000222000000->0000000224000000 (122880 pages
> to be  allocated)
> (XEN) VIRTUAL MEMORY ARRANGEMENT:
> 
> 
> -- 
> Kind  Regards
> Rudi Ahlers
> SoftDux
> 
> Website: http://www.SoftDux.com
> Technical Blog: http://Blog.SoftDux.com
> Office: 087 805 9573
> Cell: 082  554 7532
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