Hi Kelsey, I've been at this all day and can't find a thing!
I've tried using a boot parameter, but nothing worked... fdisk and sfdisk can't do GPT partition tables, and parted which can, doesn't do CHS! Do you have any words for the wise? I just can't seem to get this to work... Thanks in advance, Phil. PS: I've managed to get sfdisk to do it on a 768GB partition. When I use sfdisk a second time, it reports that the partition table has been built with the wrong parameters, but it'll use it for this session... I formatted the partition and exported it with qaoed but got exactly the same problem. I think I'm going to go crazy here! :( ----- Original Message ----- From: "kelsey hudson" <[EMAIL PROTECTED]> To: "Phillip Bennett" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Tuesday, July 08, 2008 7:08 PM Subject: Re: [Aoetools-discuss] Introduction > Hi Phil, > > Phillip Bennett wrote: >> I see in the archives there are questions and statements regarding the >> partition table being mis-aligned when using AoE/vblade and this causing >> more reads than needed. I used iostat to monitor at a disk I was writing >> to over the network (dedicated switch, balance-rr bonding) and saw that >> there seemed to be about 20+ times more READS than there was WRITES! I >> believe this is the problem people were talking about, so is there a fix, >> or some special way to get around this? Currently I can get 1.4Gb/sec >> over the network (iperf) andat least 110+MB/sec with hdparm on the AoE >> device. However, if I try to copy anything over to the disk, it can hit a >> maximum of about 20-27MB/sec. Is this normal? > > This sounds like you're hitting the cache alignment problem. The > ridiculous amount of reads is a cache backfill penalty. > > I did a technical write-up of the problem, which is available at: > > http://nemesis.damnit.us/~khudson/text/aoe-caching-alignment.pdf > > let me know if you have any questions. > > Alternatively to changing your disk's geometry, you can turn off caching > on the target by opening the exported block devices with O_DIRECT (however > this has its own performance implications). > > Not sure how you accomplish this with vblade or if it's even possible > without a source code hack. I've long since switched to qaoed. > > -kelsey > **Come to our Silver Anniversary Technology Meeting. Email [EMAIL PROTECTED] for further information.** ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Aoetools-discuss mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/aoetools-discuss
