ZFS sub-optimal performance with default setting

[Adam Vande More]

On Fri, Jan 11, 2013 at 8:43 AM, Patrick Dung <patrick_dkt at yahoo.com.hk>wrote:

> Hi Tom,
>
> To make it simple, I have setup in this setting:
>
> Host: Intel dual core 3Ghz CPU, RHEL 6.3 x64, RAM 8GB
>
> Freebsd 9.1 -i386 VM with these setting:
> CPU: One
> Memory: 2GB
> 5GB for OS (da1)
> 5GB for ZFS (da2), no separate ZIL
>
> Installed software:
> Postgresql 9.2.2 (compile from ports) /usr/local/pgsql is a ZFS dataset
> OTRS 3.1.6 (compile from ports)
> Apache 2 install from packages
>
> zfs/postgresql/otrs/apache is in default setting, except I have turned off
> atime in ZFS.


I might make the argument ZFS isn't necessary or all that useful in this
setup while adding quite a bit of overhead.  About all you get over a UFS
version is cheap snapshotting and even UFS can snapshot 50 GB with
relatively low overhead.  Single disk ZFS systems do also offer things like
integrity checking, but UFS would still work fine for your use case.
 Additionally, I would still be worried about stability under load on a low
mem 32 bit install.


-- 
Adam Vande More