Is it me or is FreeBSD slower on Xen than Linux?

[Roger Pau Monné]

On Tue, Aug 16, 2016 at 04:05:30PM +0200, rainer at ultra-secure.de wrote:
> Am 2016-08-16 15:48, schrieb Borja Marcos:
> > > On 16 Aug 2016, at 15:41, rainer at ultra-secure.de wrote:
> > > 
> > > Am 2016-08-16 15:38, schrieb Borja Marcos:
> > > > 
> > > > Maybe this is too obvious, my apologies in that case. But, how have
> > > > the filesystems been
> > > > created and mounted? Asynchronous? Synchronous? Journalling?
> > > > Softupdates in the case of
> > > > FreeBSD UFS? It can make quite a difference.
> > > 
> > > 
> > > FreeBSD
> > > 
> > > /dev/ada2p1 on /home/db (ufs, local, soft-updates)
> > > 
> > > 
> > > 
> > > Linux:
> > > /dev/mapper/system-lvm--home /home           ext4    defaults
> > > 0       2
> > > 
> > > 
> > > What does "defaults" mean, BTW?
> > 
> > That’s the mother of the lamb, we use to say in Spain ;)
> > 
> > I guess it depends on the particular distribution, not just on being
> > ext4. Is there a tool similar to
> > dumpfs on Linux?
> 
> 
> Apparently, it's in
> cat /proc/mounts
> 
> /dev/mapper/system-lvm--tmp /tmp ext4 rw,relatime,data=ordered 0 0
> /dev/mapper/system-lvm--var /var ext4 rw,relatime,data=ordered 0 0
> /dev/mapper/system-lvm--home /home ext4 rw,relatime,data=ordered 0 0
> /dev/mapper/system-lvm--varlog /var/log ext4 rw,relatime,data=ordered 0 0
> 
> 
> 
> 
> > You can also experiment with the FreeBSD options, maybe it will be a
> > quicker route. Try to mount as asynchronous.
> > In case it  makes a big difference, you got it.
> 
> But I don't really want to mount it asyncronous.
> Would it help to have journaling?
> 
> Or is soft-updates already the "optimum"?

I'm not saying it's not possible, but are you sure this slowdown is caused 
by the disk? It's certainly a possibility, but I would like to make sure 
it's caused by that before jumping into conclusions.

Can you load the full database in RAM and perform the same test. TBH, I 
don't use MariaDB, so I'm not sure what's the best way to achieve this, but 
a quick search on google shows there are multiple ways. In any case, make 
sure with iostat that the database is not read from the disk.

Roger.