Re: [gentoo-user] 1-Terabyte drives - 4K sector sizes? -> bar performance so far

[J. Roeleveld]

On Wednesday 10 February 2010 17:37:47 Stroller wrote:
> On 10 Feb 2010, at 11:14, J. Roeleveld wrote:
> > On Wednesday 10 February 2010 02:28:59 Stroller wrote:
> >> On 9 Feb 2010, at 19:37, J. Roeleveld wrote:
> >>> ...
> >>> Don't get me started on those ;)
> >>> The reason I use Linux Software Raid is because:
> >>> 1) I can't afford hardware raid adapters
> >>> 2) It's generally faster then hardware fakeraid
> >>
> >> I'd rather have slow hardware RAID than fast software RAID. I'm not
> >> being a snob, it just suits my purposes better.
> >
> > I don't consider that comment as "snobbish" as I actually agree.
> > But as I am using 6 disks in the array, a hardware RAID card to
> > handle that
> > would have pushed me above budget.
>
> See, for example, eBay item 280459693053.
>
> LSI is also a popular brand amongst Linux enthusiasts.
>
> 3ware have been taken over by LSI and their support has deteriorated
> over the last few months, but 3ware cards come with transferrable 3
> year warranty, expiry date identifiable by serial number, and you will
> often find eBay cards are still in warranty.

Yes, except that I tend to avoid eBay as much as possible for reasons that 
don't belong on this list.

> > My mainboard has PCI, PCI-X and PCI-e (1x and 16x), which connector-
> > type would
> > be best suited?
>
> PCI-e, PCI-X, PCI in that order, I *think*.
>
> PCI-X is very good, IIRC, it may be fractionally faster than PCI-e,
> but I get the impression it's going out of fashion a bit on
> motherboards.
>
> PCI-e is very fast and is the most readily usable on new & future
> motherboards. It is what one would choose if buying new (I'm not sure
> if PCI-X cards are still available), and so it is the most expensive
> on the secondhand market.

I know at least one shop in NL that sells them (They're also online)

> Some 3ware PCI-X cards (eg the 9500S at least) are usable in regular
> PCI slots, obviously at the expense of speed. Not sure about other
> brands.
>
> Avoid 3ware 7000 & 8000 series cards - they are now ancient, although
> you can pick them up for £10.
>
> > Also, I believe a PCI-e 8x card would work in a PCI-e 16x slot, but
> > does this
> > work with all mainboards/cards? Or are some more picky about this?
>
> No idea, sorry. I would have thought so, but I don't use PCI-e here yet.

It's what all the buzz says, but I've yet to have that confirmed. It's 
especially the size of the slots and the cards where my concerns come from.

> >> I would be far less invested in hardware RAID if I could find regular
> >> SATA controllers which boasted hot-swap. I've read reports of people
> >> hot-swapping SATA drives "just fine" on their cheap controllers but
> >> last time I checked there were no manufacturers who supported this as
> >> a feature.
> >
> > The mainboard I use (ASUS M3N-WS) has a working hotswap support
> > (Yes, I tested
> > this) using hotswap drive bays.
> > Take a disk out, Linux actually sees it being removed prior to
> > writing to it
> > and when I stick it back in, it gets a new device assigned.
>
> This is very interesting to know.
>
> This would be very useful here, even if just for auxiliary use -
> swapping in a drive from another machine just to clone it, backup or
> recover data, for instance.

Yes, but just for cloning, wouldn't it be just as easy to power down the 
machine, plug in the drive and then power it back up?
Or even stick it on a quick-change USB-case? :)

> If I found an Atom-based board that did hotswap on its normal SATA
> ports I would probably purchase one in a flash.
>
> > On a different machine, where I tried it, the whole machine locked
> > up when I
> > removed the disk (And SATA is supposed to be hotswappable by
> > design...)
>
> This is what I would normally expect, at least from when I last
> checked a year or two ago.

I do have to say here that the mainboard for that machine is now easily 5 
years old, so I didn't actually expect it to work.

> AIUI SATA by design *may* be hotswappable at the *option* of the
> manufacturer.
> (Please correct me if I am mistaken)

I think it depends on if the controller actually sends the correct signals to 
the OS as I'm not sure if it was Linux or the hardware locking up.