Subject: Re: [vserver] Sponsoring VServer getting up to date with mainline
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Fri, 22 Aug 2008 22:20:09 +0200

On Fri, Aug 22, 2008 at 09:30:17PM +0200, Daniel Hokka Zakrisson wrote:
> Herbert Poetzl wrote:
> > On Fri, Aug 22, 2008 at 06:57:55PM +0100, Ed W wrote:
> >> Herbert Poetzl wrote:
> >> >situation: one of my raid controllers suddenly failed
> >> >and I need to replace it with a new one (currently
> >> >the raid is offline, and I don't have access to the
> >> >data). as I was not very happy with the controller
> >> >(an Intel/LSI one, which only caused issues from the
> >> >beginning), I want to replace it with a different
> >> >model from Adaptec (specifically the RAID 31605),
> >> >which seems to have good support and all the features
> >> >I am looking for.
> >>
> >> Just an aside, but can I ask why a fancy raid controller?
> >
> > that's simple, with 12+ disks you have almost no
> > chance to attach them to _any_ motherboard ...
> >
> > besides that, normal SATA controllers do not have
> > the bandwith to get performant I/O over e.g.
> > port multipliers, so the only choice is a big
> > throughput raid controller ... note that I could
> > live without the fancy hardware raid features,
> > but you really don't get any 8-16 port SATA
> > controller without hardware raid ...
> 
> For this, I use Supermicro's AOC-SAT2-MV8. It's an 8-port card that
> costs less than 100 USD, though it does require a PCI-X slot. Granted
> it's got a Marvell chipset, but I haven't had any problems with it.

hmm, definitely worth a thought. are there any 
dual PCI-X motherboards for Core2 Intels out there
(preferably with good linux support :)?

> > note that disk I/O is the main bottleneck of
> > todays servers/machines, and compiling kernels
> > means moving a lot of data from/to disk
> >
> >> I personally LOVE the top end stuff, for example have some very good
> >> experiences with Compaq battery backed scsi controllers. But I have
> >> had nothing but disappointment with even decent 3Ware controllers
> >> and I notice no difference at all over builtin SATA controllers,
> >> which coupled with a nice motherboard often mean you can have 8-10
> >> controllers right on the bridge and hence high speed access
> >>
> >> Battery backup is missing off the onboard controllers though and if
> >> you have a DB application (probably not if you are getting 1.5GB
> >> disks) then this is a big deal, but otherwise it's not likely to make
> >> much difference (hey not teaching you to suck eggs - I'm sure you
> >> already know if it will help your workload!)
> >
> > yes, as mentioned, it definitely helps my specific
> > workload to maximize disk I/O and minimize latency
> >
> >> In summary though unless you need the battery backup I would recommend
> >> a new motherboard with enough onboard ports to meet your needs -
> >> forget what I have but I bought some bits of the office machine and it
> >> supports my quad intel thing with I think 8+ sata ports?
> >
> >> > and I could
> >> >also make good use of three or four of those new
> >> >1.5TB SATA disks from Seagate (ST31500341AS) or the
> >> >1TB models (ST31000340AS) to retire one of my older
> >> >disk arrays (150-200 USD/ 120-150 EUR each)
> >>
> >> The 1.5TB have quite a price hike, even the 1TB are I think slightly
> >> above the sweet spot still? I just bought 5x 1TB drives and the
> >> Samsung spinpoints were the best value - not had any problems with
> >> them so far, but don't load them much either.
> >
> > the 1TB disks specified above have 32MB cache, 5 years
> > of manufacturer warranty, they don't suck power, and
> > most important, this series has been working for me
> > for some time now (the price is roughly 0.12 EUR/GB,
> > where e.g. a U320 SCSI disk ranges at 1.2 EUR/GB :)
> >
> > note that the Samsung F1 Raid costs more than the
> > Seagate model, and I'm not convinced about the SpinPoint
> > series, as they had bad publicity (overheating and such)
> 
> Here, the Samsung drives are cheaper. As for the risk of overheating,
> my Seagate drives are warmer than my Samsung drives, even though the
> Samsung disks are under "heavier" load. But whatever you're the most
> comfortable with is best... after all, it is your data :-)

I'm not strictly against them, just don't have much
experience with the Samsung F1 Raid Series ...

thanks for the input,
Herbert

> -- 
> Daniel Hokka Zakrisson