Doesn't a journeling FS incure speed penalities due to the fact that all
disk activity is logged?
>From what I figured out mirrored disks(RAID 1) are pretty quick and are
100% fault tolerant (there is always a spare and it's always up to date.)
I'm gonna start with mirroring (2 9.1 GB quantum ATLAS IV's and an ADAPTEC
2490 UW SCSI-2 controller. Mainly for a centrailized databased using
linux's raid tools for software raid.
Paul Farber
Farber Technology
[EMAIL PROTECTED]
Ph 570-628-5303
Fax 570-628-5545
On Fri, 19 Nov 1999, John White wrote:
> On Fri, Nov 19, 1999 at 09:57:44AM -0800, Matthew Brown wrote:
> > John White wrote:
> > > IMHO, no software mirroring scheme is going to do the trick. AND
> > > they're overwhelmingly expensive.
> >
> > As to the latter point, isn't DiskSuite included in your Solaris license
> > these days?
>
> No. One has to buy a special edition of the OS to get DS.
>
> > On the former point: why is such a huge proportion of the world doing their
> > mirroring with software RAID (generally Veritas) including some HUGE solaris
> > installations (Sun seems quite keen on Veritas).
>
> Probably because those installations are supporting a qmail queue
> on their giant SW RAIDs.
>
> > > Software RAID is, again IMHO, not suitable for making your queue
> > > redundant or quick.
> >
> > I've met many people who are of the opinion that software RAID is no slower
> > than most hardware RAID. Or is the 'most' the important word here?
>
> The phrase "writeback cache" is what's important.
>
> Disk i/o is a bottleneck. SW RAID 1 exacerbates that bottleneck.
>
> If redundancy is all you want, I'd reccomend a HW RAID 1 with a cache to
> smooth out the spikes in usage. If you needed continuous high performance,
> I'd go with a 1+0 configuration with more cache AND a journaled fs.
>
> John
>
