Some comments on ZFS

[Joao Barros]

On 4/16/07, Joerg t <tjoerg at yahoo.com> wrote:
> > My system shows significant worse performance with ZFS - I suspect that this
> > is because the devices are part of a ATAPI-RAID 0  already
>
> > but here is the story - A
>
> > UFS + Softupdates -
>
>  > make -j 4 buildworld - app. 24 Min (Debugging kernel)
>
> > ZFS same command but with usr/obj on ZFS
>
> > make -j 4 buildworld - app. 1h12m
>
> > The weird thing is that one sees some fantastic peak transfer numbers e.g.
> > up to 112MB/s - Compression is off
>
> I'm also seeing a very odd behavior  regarding  memory consumption,
> with src and obj under zfs (different filesystems, same pool, compression off) the system begin to wire all memory and swap tops 1GB. Maybe there's something trashing memory on zfs ?
>
> this is a 1GB pentium 4 HT enabled box.
> building a debug enabled kernel to help figure things out.
>

UFS with SoftUpdates on a ad0 <SAMSUNG SV3012H/RD100-06> ATA/ATAPI
revision 6 20GB
make buildkernel : 23.5 mins

ZFS with compresson=gzip on  4x 320GB SATA RAIDZ
make buildkernel: 27.5 mins

systat -vm output after making the kernel on the ZFS volume:

Mem:KB    REAL            VIRTUAL                       VN PAGER   SWAP PAGER
        Tot   Share      Tot    Share    Free           in   out     in   out
Act   21884    2928    91768     4968  818472  count
All  189320    4484  2230492     8592          pages

This is on:

FreeBSD 7.0-CURRENT #5: Tue Apr 10 00:06:35 WEST 2007
    root at xeon.bsdtech.org:/usr/obj/usr/src/sys/GENERIC
WARNING: WITNESS option enabled, expect reduced performance.
acpi_alloc_wakeup_handler: can't alloc wake memory
ACPI APIC Table: <IntelR AWRDACPI>
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Xeon(TM) CPU 3.06GHz (3073.65-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0xf29  Stepping = 9
  Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE
,SSE2,SS,HTT,TM,PBE>
  Features2=0x4400<CNXT-ID,xTPR>
  Logical CPUs per core: 2
real memory  = 1072562176 (1022 MB)
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1

With HTT enabled

-- 
Joao Barros