Archived from groups: comp.sys.ibm.pc.hardware.storage (
More info?)
Folkert Rienstra wrote:
> "DanielEKFA" <sorry.no.em@il.i.get.vira.and.spam> wrote in message
> news:2vi68uF2kol2dU2@uni-berlin.de
>> DanielEKFA wrote:
>> > Alex Vilner wrote:
>> >
>> > > Hello,
>> > >
>> > > It is tough to find a single technical resource to answer all the
>> > > questions, so this group seems like the best place
)
>> > >
>> > > I have a P-4 machine (3Ghz, 1.5 Gig RAM), with 2 hard drives, 2
>> > > CD/DVD drives (one reader, one writer), so my IDE connections are
>> > > maxed out. The 2 hard drives are about 120 Gig each. The primary
>> > > bootable drive has the OS, all apps and personal files. The second
>> > > drive is split into two partitions, one is for temp storage (swap
>> > > file, and the junk), and one for backup, onto which I regularly do
>> > > DriveImage of the primary drive. With digital photography and
>> > > ever-increasing size of image files, I am beginning to see the need
>> > > to expand on the storage, while maintaining a good backup of the
>> > > data.
>> > >
>> > > The machine has 6 USB 2.0 connections and a FireWire port. Most of
>> > > USBs are used (2 printers, PDA, camera, card reader, mouse, etc..)
>> > > but the firewire is available, and so are 2-3 PCI slots.
>> > >
>> > > I am looking for an EXTERNAL solution that would allow the following:
>> > > 1. RAID-1 (for recoverability. I guess, mirroring is the best thing I
>> > > can do, unless I went with RAID-5).
>> > > 2. Fairly fast excess (by fairly fast I mean comparable to internal
>> > > drive access, since the data files will pretty much be migrated
>> > > over). 3. Accessible in the PC-DOS mode (I have yet to figure out
>> > > another way of doing drive image of an active Windows XP drive).
>> > > 4. Sharing among home networked computers.
>> > > 5. Growth potential -- so, probably, at least 4 disks of 250-300Gig
>> > > each... This, with mirroring should provide 500-600Gig usable, which
>> > > is ok in my book
>> > >
>> > > I have seen Firewire/USB drive enclosures, that go for $120-200,
>> > > without disks... So this may be a good option, other than building a
>> > > new desktop for just the storage...
>> > >
>> > > Now, for questions:
>> > > Am I nuts to consider this? What other people have done to address
>> > > growing storage needs and the reliability of storage? Will Windows XP
>> > > Pro allow me to do dynamic disk and RAID-1 (or 5) on the
>> > > Firewire-connected drive?
>> > >
>> > > Any suggestions/references would be greatly appreciated.
>> > >
>> > > Thank you in advance!
>> > >
>> > > --Alex
>> >
>> > With the kind of dough you'd put out on four external drives of that
>> > size of which you'd only have storage space equivalent to two of them
>> > since you'd be running RAID1, I'd say you'd be much better off (and
>> > save
>> > some money) with an internal RAID5 capable card and four drives of
>> > which you'd have space equivalent to three. Finding a hardware USB or
>> > Firewire solution that can do RAID would be difficult if not
>> > impossible,
>
> FireWire connected External Raid may be available.
>
Which is what I said.
>> > so you'd be using software RAID, which would strain your processor.
>
> Over FireWire?
>
Over any protocol. If you don't have hardware RAID, the other option is
software RAID. See how it works?
>> > Also, even if you have 6 USB plugs and one or more Firewire plugs you
>> > can be pretty certain that they're running off of the same hub, so
>> > you'd have to
>> > buy an extra Firewire card for each disk to prevent bottlenecks.
>
> FireWire Hubs?
>
Yeah, or "channel" or whatever the word is. You're not exactly helping here,
if you have the right word, write it!
>> > I say Firewire,
>> > because for disk use Firewire is preferable to USB even if the speed is
>> > 80 Mbps lower, because Firewire is unmanaged whereas USB is managed
>
>> > i.e. USB uses your processor a lot while transferring, Firewire does
>> > not).
>
> And what do you think your processor is doing during IO?
>
Less with Firewire than it is with USB. Firewire features a P2P-like
topology that doesn't require management like USB does with its star
topology where nothing can happen without the star. One Firewire peer can
communicate completely un-managed (ie. without a star, or if you like,
computer) with another peer, whereas USB cannot. Everything goes through
the star. I was told that this would significantly decrease CPU usage,
although studying up on it, the difference seems to be only about 10-15% to
Firewire's advantage, so it may not be the decisive factor. But either way,
Firewire is still much faster than USB2.0 as you can see for instance in
this test where Firewire 400 outperforms USB2.0 by as much as 70%:
http://www.g4techtv.com/freshgear/features/39129/USB_20_Versus_FireWire_pg3.html
>> Also, the transfer bandwidth is unlikely to be maxed out anyway.
>
> The bandwidth is lower than that of PCI and you ramble about maxing out
> PCI?
>
You really are a very bad reader, aren't you? Where exactly do you see me
saying PCI? I've been talking about Firewire the whole paragraph, and you
think I'm talking about PCI bandwidth? Now what kind of feeble brain would
draw that conclusion? But allow me to help you understand: Even if the Mbps
figures used in the Firewire and USB specs were more than theoretical
(read: accurate), then whether you had 480 Mbps or 400 Mbps wouldn't make
much of a difference since the drives used in external solutions won't be
reading or writing data at either speed anyway, except for short bursts
(and still Firewire is faster). Get it now or should I draw you a picture?
>> >
>> > But back to the point: If you can do with old school ATA instead of
>> > SATA, I can heartily recommend the Promise Fastrack SX4000 or 8000
>> > (four or eight drives supported). It has hardware RAID5 (XOR processor
>> > on-board), up to 256 MB buffer, it's realiable and cheap. I own one,
>> > and I can confirm that it does work in DOS albeit at reduced speed. I
>> > use DOS based Ghost to make backups of a 6GB XP system partition and
>> > that takes over an hour, so you can see speed isn't impressive in DOS,
>
>> > I think because the card runs in some kind of compatibility mode.
>
> Or just plain DOS mode. Learn how to use DOS to get your speed back.
>
I've used DOS since 1989, and I think I know DOS pretty well. So unless you
know this particular card and have a trick, your comment isn't exactly
useful. But just for kicks, let me know what it is you think would help in
DOS to get full performance with such a card.
>> > But anyway, if you're doing backup of a system drive you'd probably
>> > like it to be as small as possible anyway, so you're probably already
>> > installing programs to a different partition, right?
>> >
>> > I have to say that I specifically looked for an ATA RAID5 card when I
>> > bought mine, because I already owned three identical ATA disks, and I
>> > wanted something cheaper too.
>
>> > So looking for a S-ATA RAID5 drive
>
> Card.
>
>> > is probably a good idea, just make sure that
>> > a) There's an XOR processor on-board so it doesn't use your CPU, and
>
>> > b) One channel per drive is preferable to two,
>
> Clueless. S-ATA *is* one drive per channel.
>
>> > meaning that you'd like e.g. four master drives,
>
> There is no master slave in S-ATA.
>
Well that's good, then that won't be an issue.
>> > not two masters and two slaves. The Fastrack cards have four and eight
>> > channels respectively, so there's a dedicated channel for each drive.
>> >
>> > HTH,
>> > Daniel
>> >
>>
>> Oh, one more reason I bought ATA: Unless you have PCI-X, you won't get
>> any transfer speed increase from SATA, since the bottleneck would be the
>> PCI bus.
>
> Clueless. There is no difference between ATA and SATA re PCI.
>
Huh? How retarded are you trying to show yourself off as? PCI offers 132
MBps, PCI-X 1064 MBps. You wouldn't call that a speed difference?
Especially taking into account that all PCI cards (on-board and in slots)
are sharing that one bus speed? Have you even considered the fact that a
decent RAID5 card will sport a large buffer, like the SX's 256 MB buffer
capability? Or do you need more clues?
>> If you went with 10000+ RPM SATAs though, you'd get better seek times,
>> but for 7200 RPM drives on a regular PCI bus, it wouldn't matter if you
>> got ATA or S-ATA.
>
>> Someone please correct me if I'm wrong here.
>
> Done. You even corrected yourself.
I'm not sure who - if any - taught you communicative skills, but you should
definitely go back to school and learn to actually express the corrections
rather than calling people "clueless" and generally appearing like a
smart-assed wise and beautiful woman. Or perhaps you really *are* a smart-assed wise and beautiful woman? Because
for sure you haven't been very kind nor very helpful. Out of the handful of
comments you've made to my post, only one has been informative, the rest
has just been bashing (and/or incorrect). You don't belong in a forum, you
belong in a bar.
--
I win!