Re: NCQ general question

2006-03-04 Thread Jeff Garzik
Raz Ben-Jehuda(caro) wrote: Is NCQ supported when setting the controller to JBOD instead of using HW raid? 1) The two have nothing to do with each other 2) It sounds like you haven't yet read http://linux-ata.org/faq-sata-raid.html Jeff - To unsubscribe from this list: send the line

Re: NCQ general question

2006-03-04 Thread Raz Ben-Jehuda(caro)
Is NCQ supported when setting the controller to JBOD instead of using HW raid? On 3/5/06, Eric D. Mudama <[EMAIL PROTECTED]> wrote: > On 3/4/06, Steve Byan <[EMAIL PROTECTED]> wrote: > > On Mar 4, 2006, at 2:10 PM, Jeff Garzik wrote: > > > Measurements on NCQ in the field show a distinct performan

mdadm vs RAIDframe

2006-03-04 Thread A G
Hi, I'm interested to implement a software RAID system with a few SATA drives. I'm currently looking at mdadm on Linux and RAIDframe on NetBSD. Does anyone have experiences in both of these implementations? Which one is more robust? Thanks, Sean Lee ___

Re: NCQ general question

2006-03-04 Thread Eric D. Mudama
On 3/4/06, Steve Byan <[EMAIL PROTECTED]> wrote: > On Mar 4, 2006, at 2:10 PM, Jeff Garzik wrote: > > Measurements on NCQ in the field show a distinct performance > > improvement... 30% has been measured on Linux. Nothing to sneeze at. > > Wow! 30% is amazing. I'd be interested in knowing how the

Re: NCQ general question

2006-03-04 Thread Steve Byan
On Mar 4, 2006, at 2:10 PM, Jeff Garzik wrote: Steve Byan wrote: Data integrity -and- performance. Performance increases for all the standard reasons that an asynchronous pipeline increases performance over a synchronous one. The write cache means that requests on the device can be

Re: No syncing after crash. Is this a software raid bug?

2006-03-04 Thread Kasper Dupont
> However, since "inconsistent parity information in raid[456] is equal > to "different mirrors" in raid1, there is no real difference. There is a major difference. Inconsistent parity information can eventually lead to corruption in another sector in the stripe. Assume there are two data disks an

Re: NCQ general question

2006-03-04 Thread Jeff Garzik
Steve Byan wrote: On Mar 3, 2006, at 5:19 PM, Jeff Garzik wrote: Steve Byan wrote: it. It works OK for reads. TCQ was really invented as a way to allow CD-ROM drives to play nice on the same ATA bus as disks. Disagree, you are probably thinking about bus disconnect associated with the

Re: NCQ general question

2006-03-04 Thread Steve Byan
On Mar 3, 2006, at 5:19 PM, Jeff Garzik wrote: Steve Byan wrote: it. It works OK for reads. TCQ was really invented as a way to allow CD-ROM drives to play nice on the same ATA bus as disks. Disagree, you are probably thinking about bus disconnect associated with the overlapped command s

Re: No syncing after crash. Is this a software raid bug?

2006-03-04 Thread Kasper Dupont
> If it relies on static page content during updates of its mirrors, it > need to take a private copy of the page(s). And by that you mean that raid5 and raid6 must copy the page contents before writing it to disk? -- Kasper Dupont -- Rigtige mænd skriver deres egne backupprogrammer #define _(_)

Re: No syncing after crash. Is this a software raid bug?

2006-03-04 Thread Heinz Mauelshagen
On Sat, Mar 04, 2006 at 12:01:50AM +0100, Mario 'BitKoenig' Holbe wrote: > Heinz Mauelshagen <[EMAIL PROTECTED]> wrote: > > On Fri, Mar 03, 2006 at 03:30:29PM +0100, Mario 'BitKoenig' Holbe wrote: > >> But when a dirty page is modified while it's being accessed, it stays > >> dirty and gets cleaned