On Tue, Jan 19, 2010 at 08:36:58AM -0500, Mark Johnson wrote:
> 
> 
> J. Landamore wrote:
> >Mark,
> >
> >Sorry about the delay
> 
> Don't see anything obvious below... Did you get a chance to
> try a PV OpenSolaris guest?

We tried the PV OpenSolaris guest and there isn't an improvement.  Our
next move is to scrap xVM completely and try the hardware with stock
Solaris 10u8 and zones to check that we aren't asking too much of the
hardware.

John

> 
> 
> 
> MRJ
> 
> 
> 
> >On Mon, Jan 11, 2010 at 08:39:47AM -0500, Mark Johnson wrote:
> >>
> >>[email protected] wrote:
> >>>We have 2 sets of identical hardware, identically configured, both 
> >>>exhibiting disk i/o performance problems with 2 of their 4 DomUs
> >>>
> >>>The DomUs in question each act as a nfs filesever. The fileserver is 
> >>>made up from 2 zvols, one holds the DomU (solaris 10) and the other is 
> >>>mounted to the DomU and contains the user's files which are then nfs 
> >>>exported. Both zvols are formatted as UFS. For the first 25-30 nfs 
> >>>clients performance is OK, after that client performance drops off 
> >>>rapidly e.g. a "ls -l" of the user's home area taking 90 seconds. 
> >>>Everything is stock - no tuning.
> >>When does xentop report for the guest? For both dom0 and dom0,
> >>what does iostat -x report?
> >
> >During "normal" running the stats are
> >
> >xentop:
> >      NAME  STATE   CPU(sec) CPU(%)     MEM(k) MEM(%)  MAXMEM(k) MAXMEM(%)
> >VCPUS NETS NETTX(k) NETRX(k) VBDS   VBD_OO   VBD_RD   VBD_WR 
> >SSID
> >  achilles -----r       2412  120.1    1580792   18.8    1581056      18.8
> >2    1   161632     8712    4        0      682     1006 
> >   0
> >  Domain-0 -----r      90049  164.1    2097152   25.0   no limit       n/a
> >2    0        0        0    0        0        0        0 
> >   0
> >
> >Dom0 iostat:
> >device    r/s    w/s   kr/s   kw/s wait actv  svc_t  %w  %b 
> >sd0       0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
> >sd1       0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
> >sd2     486.7    0.0 4713.3    0.0  0.0  0.9    2.0   1  79 
> >
> >DomU iostat:
> >device    r/s    w/s   kr/s   kw/s wait actv  svc_t  %w  %b 
> >cmdk0     0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
> >cmdk1   126.5  331.7 2593.7 3324.2  0.0  7.5   16.4   1  89 
> >cmdk2     0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
> >
> >
> >When performance drops off we get
> >
> >xentop:
> >      NAME  STATE   CPU(sec) CPU(%)     MEM(k) MEM(%)  MAXMEM(k) MAXMEM(%)
> >VCPUS NETS NETTX(k) NETRX(k) VBDS   VBD_OO   VBD_RD   VBD_WR 
> >SSID
> >  achilles --b---       2475    0.6    1580792   18.8    1581056      18.8
> >2    1        0        0    4        0        0       14 
> >   0
> >  Domain-0 -----r      90140    7.1    2097152   25.0   no limit       n/a
> >2    0        0        0    0        0        0        0 
> >   0
> >
> >Dom0 iostat:
> >device    r/s    w/s   kr/s   kw/s wait actv  svc_t  %w  %b 
> >sd0       0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
> >sd1       0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
> >sd2      39.7  161.3 2199.0 5919.7  0.0 17.7   88.2   0 100 
> >
> >DomU iostat:
> >device    r/s    w/s   kr/s   kw/s wait actv  svc_t  %w  %b 
> >cmdk0     0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
> >cmdk1     1.3    1.0   26.7    4.0  5.7 32.0 16164.7 100 100 
> >cmdk2     0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0  
> >
> >istats persist like this for 4 or 5 seconds and then drop back towards
> >"normal" but performance on the client remains very poor.
> >
> >Thanks
> >
> >John
> >
> >
> >>What Solaris 10 update?
> >>
> >>Have you tried a PV opensolaris guest for the NFS server
> >>running the latest bits?  If not, can you do this? There
> >>have been some xnf (NIC driver) fixes which could explain
> >>this.
> >>
> >>
> >>
> >>>Anyone any suggestions what I can do to improve matters - would using 
> >>>ZFS rather than UFS for the user disk change matters?
> >>
> >>It should not.
> >>
> >>
> >>
> >>>The underlying disks are managed by a hardware RAID controller so the 
> >>>zpool in the Dom0 just sees a single disk.
> >>Why wouldn't you use the disks as a jbod and give them all to
> >>zfs?
> >>
> >
> 

-- 
John Landamore

Department of Computer Science
University of Leicester
University Road, LEICESTER, LE1 7RH
[email protected]
Phone: +44 (0)116 2523410       Fax: +44 (0)116 2523604

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