RE: [gentoo-user] Well, my RAID array is screwed (was df != fdisk )
> >Agreed. I have three systems right now that are fully RAIDed, one a >high use server, a personal server, and my personal workstation, all of >which use software raid, one of which uses a PCI-IDE card (promise >tx-2000 or something) to add the extra channels that are needed. I use one of Promise's cheaper controllers to add a few channels and it works flawlessly. > >Not noticably. The hdparm numbers are a bit lower than say, RAID0 >(obviously) but faster than each drive individually. I haven't noticed >any processor lag on either system I have that uses RAID5. > Thanks. I'll proceed on the assumption that I won't have any problems and order my drives sometime in the next couple of weeks. -rex -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] Well, my RAID array is screwed (was df != fdisk)
> Note that the TX4 "RAID" card, is essentially a *software* raid card > (i.e. glorified IDE controller). There is very few true IDE raid card > with support under linux. 3ware and ARCO DupliDisk are the only ones. > http://www.linux-ide.org/chipsets.html > > -Ross Do you mean by that that the pdcraid kernel module is doing the RAID work, as opposed to a chip on the card? -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] Well, my RAID array is screwed (was df != fdisk)
> > > Note that the TX4 "RAID" card, is essentially a *software* raid card > > (i.e. glorified IDE controller). There is very few true IDE raid card > > with support under linux. 3ware and ARCO DupliDisk are the only ones. > > http://www.linux-ide.org/chipsets.html > > > > -Ross > > Do you mean by that that the pdcraid kernel module is doing the RAID work, > as opposed to a chip on the card? Yes. -Ross -- [EMAIL PROTECTED] mailing list
RE: [gentoo-user] Well, my RAID array is screwed (was df != fdisk)
>It turns out that for some reason mkreiserfs only allocated >60G on my 120G >Raid array. I rebooted on my 1.4 LiveCD and attempted to >debug_reiserfs my >array, but wound up getting a screen full of I/O errors on one >of my drives >(the first one of the array). I suspect it's not actually the >drive, but the >driver that's at fault. > >In any case, I'm completely fed up with the Promise driver and >the ataraid >functionality (or lack thereof) in the kernel. hdparm can't >read the array, >mkreiserfs can't seem to make use of more than one drive's >worth of space, >etc. It's a disaster. After spending weeks of calendar time >and dozens of >hours trying to get it all to work, I'm backing off. > >I think I can tell the TX4 RAID card to not bother with an >array and just >run the 4 drives as independent, normal drives. Hopefully that >will allow >the kernel to better deal with them. Then, I'll attempt to use evms to >cobble them together into a software RAID 5 configuration. > >My only regret is that I'll no longer be using the RAID card >to its full >extent. However, I've also read some interesting opinions that >talk about >how a low-end RAID card (such as the tx4) can be a bottleneck >on higher-end >systems. Mine's a dual-mp 1.4Ghz (1600+) configuration. Such >opinions say >that on such a multi-processor, relatively fast system >software RAID can >actually be *faster* than relying on a card such as the tx4. I >hope that's >true! > >Eric I've had good luck with Linux software raid arrays. It's so durn easy, I don't see any reason to bother with the low end RAID cards. (The more expensive cards can offer advantages not otherwise available.) I would wonder about a software RAID 5 array, however. Doesn't RAID 5 involve a fairly robust algorithm that might drag the processor down a bit? I don't really know and am somewhat curious about this, as I have been considering the same thing on a file server. -rex -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] Well, my RAID array is screwed (was df != fdisk)
> My only regret is that I'll no longer be using the RAID card to its full > extent. However, I've also read some interesting opinions that talk about > how a low-end RAID card (such as the tx4) can be a bottleneck on higher-end > systems. Mine's a dual-mp 1.4Ghz (1600+) configuration. Such opinions say > that on such a multi-processor, relatively fast system software RAID can > actually be *faster* than relying on a card such as the tx4. I hope that's > true! Note that the TX4 "RAID" card, is essentially a *software* raid card (i.e. glorified IDE controller). There is very few true IDE raid card with support under linux. 3ware and ARCO DupliDisk are the only ones. http://www.linux-ide.org/chipsets.html -Ross -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] Well, my RAID array is screwed (was df != fdisk )
> I've had good luck with Linux software raid arrays. It's so > durn easy, I don't see any reason to bother with the low end > RAID cards. (The more expensive cards can offer advantages > not otherwise available.) Agreed. I have three systems right now that are fully RAIDed, one a high use server, a personal server, and my personal workstation, all of which use software raid, one of which uses a PCI-IDE card (promise tx-2000 or something) to add the extra channels that are needed. > I would wonder about a software RAID 5 array, however. Doesn't > RAID 5 involve a fairly robust algorithm that might drag the > processor down a bit? I don't really know and am somewhat curious > about this, as I have been considering the same thing on a > file server. Not noticably. The hdparm numbers are a bit lower than say, RAID0 (obviously) but faster than each drive individually. I haven't noticed any processor lag on either system I have that uses RAID5. -- Alan <[EMAIL PROTECTED]> - http://arcterex.net "There are only 3 real sports: bull-fighting, car racing and mountain climbing. All the others are mere games."-- Hemingway -- [EMAIL PROTECTED] mailing list
