On Saturday 07 of August 2010 00:24:08 Leonidas Spyropoulos wrote: > On Fri, Aug 6, 2010 at 7:32 PM, Sebastian 'gonX' Jensen > > <gonx@xxxxxxxxxxxxxxx> wrote: > > On 6 August 2010 20:23, Leonidas Spyropoulos <artafinde@xxxxxxxxx> wrote: > >> Do I have to change the partition ID flag of each partition? > >> Currently is set to fd (Linux Raid autodetect) for used from mdadm > >> mkfs.btrfs supports that or needs to be 83 (Linux) ? > > > > FD is for mdraid integrated into the Linux kernel. I have mine at 83. > > It won't hurt to have them at FD, but the kernel will spend extra time > > as it probes the devices on boot, causing a slight slowdown. > > Ok done them id 83 and used 3 devices eventually > Using raid0 for data and metadata > # mkfs.btrfs -m raid0 -d raid0 /dev/sdc1 /dev/sdd2 /dev/sde2 > > 2 SATA and 1 ATA drive > I thought that ATA will bottleneck the other 2 drives but seems like I gain > something from it. > Using iozone for benchmark: > # iozone -s 8g -r 1024 -i 0 -i 1 > with 2 SATA devices and then 3 devices (SATA + ATA): > KB reclen write rewrite read reread > 8388608 1024 134869 139607 229146 228800 > 8388608 1024 135151 139050 233461 235929 > > The above is with -o compress option enabled and my cpu topped up on > 100% cpu (both cores) while test and copy huge data. > Is it possible I am bottlenecked by my cpu speed? > AMD Opteron 165 @ 2700 Mhz Considering you have 100% CPU usage during the test, it would seem so. > > >> On Thu, Aug 5, 2010 at 3:40 PM, Hubert Kario <hka@xxxxxxxxxx> wrote: > >>> On Thursday 05 August 2010 16:15:22 Leonidas Spyropoulos wrote: > >>>> Hi all, > >>>> > >>>> I want to make a btrfs raid0 on 2 partitions of my pc. > >>>> Until now I am using the mdadm tools to make a software raid of the 2 > >>>> partitions /dev/sde2, /dev/sdd2 > >>>> and then mkfs.etx4 the newly created /dev/md0 device. > >>>> From performance point of view is it better to keep the configuration > >>>> of mdadm and just format the /dev/md0 device as btrfs OR > >>>> delete the raid device and format the 2 partitions /dev/sde2 /dev/sdd2 > >>>> as a btrfs with 2 devices? > >>>> mkfs.btrfs /dev/sde2 /dev/sdd2 > >>> > >>> Btrfs already supports metadata mirroring when the data is striped. > >>> What this means, is while the performance should be more-or-less > >>> identical to MD RAID0 (if it isn't it's a bug), your data is a bit > >>> more secure as the metadata describing it resides on both drives. > >>> Later on it will be possible to selct which directories/files should > >>> have what level of redundancy. This will allow to have ~/work RAID1-ed > >>> and ~/videos RAID0-ed while keeping both directories on the same > >>> partition and filesystem. > >>> > >>>> On a sidenote: > >>>> If I decide to go for raid5 which is not supported currently from mkfs > >>>> I have to use the mdadm tool anyway, right? > >>> > >>> yes, RAID5 code is not in trunk yet. > >>> > >>> -- > >>> Hubert Kario > >>> QBS - Quality Business Software > >>> 02-656 Warszawa, ul. Ksawerów 30/85 > >>> tel. +48 (22) 646-61-51, 646-74-24 > >>> www.qbs.com.pl > >> > >> -- > >> Caution: breathing may be hazardous to your health. > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" > >> in the body of a message to majordomo@xxxxxxxxxxxxxxx > >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > Regards, > > Sebastian J. > > > > PS. Please try to bottom-post rather than top-post. Here's a link I > > can advise reading for a clarification on why bottom posting is > > essential: http://www.caliburn.nl/topposting.html > > Thanks for the heads up about bottom-posting. -- Hubert Kario QBS - Quality Business Software 02-656 Warszawa, ul. Ksawerów 30/85 tel. +48 (22) 646-61-51, 646-74-24 www.qbs.com.pl -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
