I would recommend you get the current version of md and mdadm and read the documentation related to md's RAID10. I don't have the current versions myself, and can only hope the documentation has a good explanation. I believe RAID10 is for 2.6 kernels only, and I have a 2.4 kernel. Guy > -----Original Message----- > From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > owner@xxxxxxxxxxxxxxx] On Behalf Of Andrew Rechenberg Lists > Sent: Tuesday, April 26, 2005 1:24 PM > To: Guy; linux-raid@xxxxxxxxxxxxxxx > Subject: RE: raid 10 or 1+0 ? > > OK, obviously I'm missing something. :) > > Can someone explain to me the what they think the difference between > RAID0+1, RAID1+0, and RAID10, with document references please. The two > later seem to me to be the same thing and everything I can find > referencing 1+0 is describing what I know as RAID10 - a striped array > consisting of RAID1 arrays. > > > > > -----Original Message----- > > From: Guy [mailto:bugzilla@xxxxxxxxxxxxxxxx] > > Sent: Monday, April 25, 2005 5:49 PM > > To: Andrew Rechenberg Lists; linux-raid@xxxxxxxxxxxxxxx > > Subject: RE: raid 10 or 1+0 ? > > > > No, the question was not related to RAID0+1. > > I my opinion, RAID0+1 would be evil! > > RAID1+0 or md's RAID10 would be much better. > > > > Guy > > > > > > > -----Original Message----- > > > From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > > > owner@xxxxxxxxxxxxxxx] On Behalf Of Andrew Rechenberg Lists > > > Sent: Monday, April 25, 2005 4:05 PM > > > To: linux-raid@xxxxxxxxxxxxxxx > > > Subject: RE: raid 10 or 1+0 ? > > > > > > The subject of the mail should be "raid 10 or 0+1" I believe :) > > > > > > According to acnc.com: > > > > > > http://www.acnc.com/04_01_10.html > > > > > > "RAID 10 is implemented as a striped array whose segments > > are RAID 1 > > > arrays " > > > > > > http://www.acnc.com/04_01_0_1.html > > > > > > "RAID 0+1 is implemented as a mirrored array whose segments > > are RAID 0 > > > arrays" > > > > > > If a drive were to fail in a RAID0+1, what you are left with is > > > essentially one RAID0 array. > > > > > > You want to use RAID10 if you need high performance and very good > > > fault tolerance. The disadvantage is that you end up with > > half of the > > > available raw space as useable. > > > > > > I've never seen nor tried a "/" file system on RAID10 or RAID0+1. > > > What I usually hear recommended is /boot and or / on RAID1 > > and then if > > > you need better performance for a database or other > > application, then > > > create a /data partition or something of the sort on a > > separate RAID10 > > > array that is on different disk spindles. > > > > > > Here is our configuration: > > > > > > /: RAID1 > > > /backup: RAID0 disk backup staging area > > > /data: LVM on a 56 SCSI disk SW RAID10 array > > > > > > > > > HTH, > > > Andy. > > > > > > > > > > -----Original Message----- > > > > From: linux-raid-owner@xxxxxxxxxxxxxxx > > > > [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Andre Noll > > > > Sent: Sunday, April 24, 2005 9:54 AM > > > > To: linux-raid@xxxxxxxxxxxxxxx > > > > Subject: Re: raid 10 or 1+0 ? > > > > > > > > On Sat, 23 Apr 2005 12:21:17 -0400 you wrote in > > > > local.lists.linux-raid: > > > > > > > > > Maybe we need some success stories for RAID10 and RAID1+0 > > > > mounted on "/". > > > > > > > > I have such a setup up and running for quite some time now: > > > > > > > > cat /proc/mdstat > > > > Personalities : [raid0] [raid1] > > > > md3 : active raid0 md1[0] md2[1] > > > > 156247808 blocks 64k chunks > > > > > > > > md2 : active raid1 hda2[0] hdk2[1] > > > > 78123968 blocks [2/2] [UU] > > > > > > > > md1 : active raid1 hdc2[0] hdg2[1] > > > > 78123968 blocks [2/2] [UU] > > > > > > > > md0 : active raid1 hdc1[2] hda1[3] hdk1[1] hdg1[0] > > > > 49280 blocks [4/4] [UUUU] > > > > > > > > My roottfs is on a lv. The corresponding vg is made from md3. > > > > > > > > This works if you do not rely on the kernel to assemble > > your array > > > > but use an initrd to achieve this. > > > > > > > > Just use something like this in your linuxrc, right after > > creating > > > > the device nodes (if you use udev): > > > > > > > > if test -e /proc/mdstat; then > > > > log "scanning for multi disk devices" > > > > echo "DEVICE /dev/hd[a-z] /dev/sd[a-z] /dev/md[0-9]" > > > > > /etc/mdadm.conf > > > > mdadm --examine --scan --config=/etc/mdadm.conf \ > > > > >> /etc/mdadm.conf > > > > mdadm --assemble --scan > > > > fi > > > > > > > > if test -c /dev/mapper/control; then > > > > log "setting up lvm" > > > > vgscan --mknodes > > > > vgchange -a y > > > > fi > > > > > > > > > > > > BTW, you should definitively use striped mirrors rather than > > > > mirrored stripes. > > > > > > > > However, note that you can not boot from a striped mirror. > > > > That is, you need a tiny partition, preferably at the > > beginning of > > > > your discs, to store the kernel image and the initrd, but not the > > > > rootfs. You can make it a raid1 over all disks, like my > > md0 above, > > > > and use lilo to write a mbr to _all_ discs. That way you > > can shuffle > > > > around your discs and your system will still boot. > > > > > > > > More details on request ;) > > > > Andre > > > > -- > > > > Andre Noll, http://www.mathematik.tu-darmstadt.de/~noll > > > > > > > > - > > > > To unsubscribe from this list: send the line "unsubscribe > > > > linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx > > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > > > Confidentiality Notice: This e-mail message including > > attachments, if > > > any, is intended only for the person or entity to which it is > > > addressed and may contain confidential and/or privileged > > material. Any > > > unauthorized review, use, disclosure or distribution is > > prohibited. If > > > you are not the intended recipient, please contact the > > sender by reply > > > e-mail and destroy all copies of the original message. If > > you are the > > > intended recipient, but do not wish to receive > > communications through > > > this medium, please so advise the sender immediately. > > > > > > > > > - > > > To unsubscribe from this list: send the line "unsubscribe > > linux-raid" in > > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > Confidentiality Notice: This e-mail message including attachments, if any, > is intended > only for the person or entity to which it is addressed and may contain > confidential > and/or privileged material. Any unauthorized review, use, disclosure or > distribution > is prohibited. If you are not the intended recipient, please contact the > sender by reply > e-mail and destroy all copies of the original message. 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