9.0 on SSD

[Victor Sudakov]

Warren Block wrote:

[dd]

> >>> I have not done any tricky partition alignment, do I really need to? Is
> >>> anything else advisable?
> >>
> >> If it's not aligned, there can be a pretty significant performance
> >> drop.  Please show the output of 'gpart show' on that drive if it's GPT
> >> (gpart show ada0) or drive and slice if it's MBR/bsdlabel (gpart show
> >> ada0 && gpart show ada0s1).
> >
> > It was created by the "Auto" option of the new FreeBSD installer:
> >
> > [sudakov at vas ~] gpart show ada0
> > =>       34  117231341  ada0  GPT  (55G)
> >         34        128     1  freebsd-boot  (64k)
> >        162  111148928     2  freebsd-ufs  (53G)
> >  111149090    5861376     3  freebsd-swap  (2.8G)
> >  117010466     220909        - free -  (107M)
> 
> That is not aligned, either with 4K or 1M:
>    (162*512)/4096 = 20.25
> 
> If the performance is good enough, leave it alone.  Use
> # diskinfo -tv /dev/ada0p2
> to get an optimistic version, or do some in-depth benchmarking with 
> benchmarks/bonnie++.
> 
> To get it aligned, back up and repartition:

[dd]

Warren, 

Thank you very much for the useful tips. One more question regarding
SSD. The FreeBSD installer enabled journaled soft-updates on the 
filesystem which resides on the SSD. Is it good, bad or irrelevant for
the SSD ?

/dev/ada0p2 on / (ufs, local, noatime, journaled soft-updates, nfsv4acls)

-- 
Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
sip:sudakov at sibptus.tomsk.ru