Re: Boot partition mirror-raid possible?
On Thu, Jul 17, 2008 at 6:33 PM, Peter 1 Oberparleiter <[EMAIL PROTECTED]> wrote: > There are technical requirements(*) that need to be met by a lv setup > to be supported without completely redoing the current disk IPL > mechanism used for Linux on System z. The aim of any zipl enhancement > into that direction should of course be to include as many of the most > common setups as possible. I'd say it should be possible to come up with a generic IPLer that is put on each Linux disk with a 3card loader in the place &deity meant it to be. That should happen with dasdfmt rather than zipl. The generic IPLer would get its info from one of the first blocks on the payload of the disk (the MBR?) as expected by Linux tools. IIRC the Linux model supports a number of unused blocks at the start of te disk (one track is probably enough). That would free the Linux tools from dealing with the short blocks of the IPL program. -Rob -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
Linux on 390 Port wrote on 17.07.2008 16:30:27: > I hope the zipl command will also be enhanced to work with a multipathed > LUN ala the multipath-tools package. There are technical requirements(*) that need to be met by a lv setup to be supported without completely redoing the current disk IPL mechanism used for Linux on System z. The aim of any zipl enhancement into that direction should of course be to include as many of the most common setups as possible. > Or by making it support LVM (which relies on device mapper) will it > automatically support multipathed LUN since multipath-tools also relies > on device mapper? That would of course be the preferred solution. Whether all of the required logic needs to end up in zipl itself or possibly in a wrapper program is a matter of detail to be investigated. > zipl -V > Using config file '/etc/zipl.conf' > Error: Unsupported device driver 'device-mapper' That's the safety check I mentioned in my previous post. Regards, Peter * = write access to block 0+, all additional IPL data must reside on a single disk (or identical clones) -- Peter Oberparleiter Linux on System z Development IBM Deutschland Research & Development GmbH -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
Peter, I hope the zipl command will also be enhanced to work with a multipathed LUN ala the multipath-tools package. Or by making it support LVM (which relies on device mapper) will it automatically support multipathed LUN since multipath-tools also relies on device mapper? On my SLES10 SP1, zipl of multipath boot LUN complains: zipl -V Using config file '/etc/zipl.conf' Error: Unsupported device driver 'device-mapper' This e-mail, including any attachments, may be confidential, privileged or otherwise legally protected. It is intended only for the addressee. If you received this e-mail in error or from someone who was not authorized to send it to you, do not disseminate, copy or otherwise use this e-mail or its attachments. Please notify the sender immediately by reply e-mail and delete the e-mail from your system. -Original Message- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Peter 1 Oberparleiter Sent: Wednesday, July 16, 2008 11:05 AM To: LINUX-390@VM.MARIST.EDU Subject: Re: Boot partition mirror-raid possible? Linux on 390 Port wrote on 16.07.2008 11:53:12: > Should I try to mount the actual partitions under boot sequentially? I am new > to RAID and am not sure how to proceed. zipl doesn't work with logical volumes, such as RAID1-like mirror setups. The reason behind this is that zipl lacks knowledge about this type of device which prevents it from putting the right type of IPL record into the right place. Because this can cause various types of malfunctions, current versions of zipl even check whether they're pointed at a DASD or ZFCP disk and bail out if neither is the case. This is being worked on and some future version of zipl should be able to cope with a defined set of logical volume setups (no dates given though). Regards, Peter Oberparleiter -- Peter Oberparleiter Linux on System z Development IBM Deutschland Research & Development GmbH -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
On Wednesday 16 Jul 2008, Mark Post wrote: > >>> On Wed, Jul 16, 2008 at 5:53 AM, in message > > <[EMAIL PROTECTED]>, Robin Atwood <[EMAIL PROTECTED]> wrote: > > I am following a HOWTO I found to move my DASD to use LVM on top of > > RAID1. The > > instructions assume Intel arch but all goes well until it says to use > > Grub to > > write the MBR onto the two partitions with the boot directory on them. > > Naturally I tried to use zipl but it fails with: > > Peter has already indicated this won't work (today). But to follow up a > little more, I would say to think about what you're doing and why. Using > RAID 1 in a system is almost always done to prevent a system outage when a > disk fails. If that happens on a mainframe Linux system, you've got bigger > problems than worrying about whether your system will reboot if needed. > Using software RAID can make a lot of sense on Linux for System z, but I > wouldn't think that doing it for /boot (on ECKD) would be in that category. Thanks to Peter for the explicit explanation that this can't work. I am actually just carrying out an experiment to see if all this was possible. Clearly it is not essential that the boot partition is mirrored, so I shall revert that to normal. Thanks to everyone who replied! -Robin -- -- Robin Atwood. "Ship me somewheres east of Suez, where the best is like the worst, Where there ain't no Ten Commandments an' a man can raise a thirst" from "Mandalay" by Rudyard Kipling -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
>>> On Wed, Jul 16, 2008 at 5:53 AM, in message <[EMAIL PROTECTED]>, Robin Atwood <[EMAIL PROTECTED]> wrote: > I am following a HOWTO I found to move my DASD to use LVM on top of RAID1. > The > instructions assume Intel arch but all goes well until it says to use Grub > to > write the MBR onto the two partitions with the boot directory on them. > Naturally I tried to use zipl but it fails with: Peter has already indicated this won't work (today). But to follow up a little more, I would say to think about what you're doing and why. Using RAID 1 in a system is almost always done to prevent a system outage when a disk fails. If that happens on a mainframe Linux system, you've got bigger problems than worrying about whether your system will reboot if needed. Using software RAID can make a lot of sense on Linux for System z, but I wouldn't think that doing it for /boot (on ECKD) would be in that category. Mark Post -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
Linux on 390 Port wrote on 16.07.2008 11:53:12: > Should I try to mount the actual partitions under boot sequentially? I am new > to RAID and am not sure how to proceed. zipl doesn't work with logical volumes, such as RAID1-like mirror setups. The reason behind this is that zipl lacks knowledge about this type of device which prevents it from putting the right type of IPL record into the right place. Because this can cause various types of malfunctions, current versions of zipl even check whether they're pointed at a DASD or ZFCP disk and bail out if neither is the case. This is being worked on and some future version of zipl should be able to cope with a defined set of logical volume setups (no dates given though). Regards, Peter Oberparleiter -- Peter Oberparleiter Linux on System z Development IBM Deutschland Research & Development GmbH -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
Robin Atwood wrote: On Wednesday 16 Jul 2008, Rob van der Heij wrote: On Wed, Jul 16, 2008 at 12:32 PM, Robin Atwood <[EMAIL PROTECTED]> wrote: I think the problem is that my target device is /dev/md1 which is not a real disk, it's a pseudo-device manufactured by the mdadm command from two real partitions. That sure is a problem. But since you don't write to the boot partition a lot, could you not just maintain the two identical copies yourself? That's what I am beginning to think. :( I was hoping someone on the list has tried this and has a definitive answer. -Robin -- -- Robin Atwood. "Ship me somewheres east of Suez, where the best is like the worst, Where there ain't no Ten Commandments an' a man can raise a thirst" from "Mandalay" by Rudyard Kipling -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 fwiw, grub has been patched to work with RAID. A quick grep of the (Red Hat) RPM changelog shows: - add dmraid support ( [snip] - Always install in MBR for raid1 /boot/ [snip] - reworked much of how the RAID1 support in grub-install works. Not sure how hard it would be to implement this in zipl. -- Brad Hinson <[EMAIL PROTECTED]> Sr. Support Engineer Lead, System z Red Hat, Inc. (919) 754-4198 www.redhat.com/z -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
On Wed, Jul 16, 2008 at 12:58 PM, Robin Atwood <[EMAIL PROTECTED]> wrote: > That's what I am beginning to think. :( I was hoping someone on the list has > tried this and has a definitive answer. Yes, zipl uses specific ioctl() calls of the eckd driver to write the IPL record etc. -Rob -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
On Wednesday 16 Jul 2008, Rob van der Heij wrote: > On Wed, Jul 16, 2008 at 12:32 PM, Robin Atwood <[EMAIL PROTECTED]> wrote: > > I think the problem is that my target device is /dev/md1 which is not a > > real disk, it's a pseudo-device manufactured by the mdadm command from > > two real partitions. > > That sure is a problem. But since you don't write to the boot > partition a lot, could you not just maintain the two identical copies > yourself? That's what I am beginning to think. :( I was hoping someone on the list has tried this and has a definitive answer. -Robin -- -- Robin Atwood. "Ship me somewheres east of Suez, where the best is like the worst, Where there ain't no Ten Commandments an' a man can raise a thirst" from "Mandalay" by Rudyard Kipling -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
On Wed, Jul 16, 2008 at 12:32 PM, Robin Atwood <[EMAIL PROTECTED]> wrote: > I think the problem is that my target device is /dev/md1 which is not a real > disk, it's a pseudo-device manufactured by the mdadm command from two real > partitions. That sure is a problem. But since you don't write to the boot partition a lot, could you not just maintain the two identical copies yourself? -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
On Wednesday 16 Jul 2008, Rob van der Heij wrote: > On Wed, Jul 16, 2008 at 11:53 AM, Robin Atwood <[EMAIL PROTECTED]> wrote: > > Should I try to mount the actual partitions under boot sequentially? I am > > new to RAID and am not sure how to proceed. > > If you want to make another disk "bootable" you must specify the right > directory (and that must be on the target device). The reason is that > zipl creates a "bootmap" in that directory. We used to put the > zipl.conf in the /boot directory and point to that one in the command. > > Don't know whether the scheme with RAID and LVM maps well to Linux on > z/VM. If you're just looking for an extra boot device, then you might > want to share that with all the other Linux guests. I think the problem is that my target device is /dev/md1 which is not a real disk, it's a pseudo-device manufactured by the mdadm command from two real partitions. -Robin -- -- Robin Atwood. "Ship me somewheres east of Suez, where the best is like the worst, Where there ain't no Ten Commandments an' a man can raise a thirst" from "Mandalay" by Rudyard Kipling -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Re: Boot partition mirror-raid possible?
On Wed, Jul 16, 2008 at 11:53 AM, Robin Atwood <[EMAIL PROTECTED]> wrote: > Should I try to mount the actual partitions under boot sequentially? I am new > to RAID and am not sure how to proceed. If you want to make another disk "bootable" you must specify the right directory (and that must be on the target device). The reason is that zipl creates a "bootmap" in that directory. We used to put the zipl.conf in the /boot directory and point to that one in the command. Don't know whether the scheme with RAID and LVM maps well to Linux on z/VM. If you're just looking for an extra boot device, then you might want to share that with all the other Linux guests. -Rob -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
Boot partition mirror-raid possible?
I am following a HOWTO I found to move my DASD to use LVM on top of RAID1. The instructions assume Intel arch but all goes well until it says to use Grub to write the MBR onto the two partitions with the boot directory on them. Naturally I tried to use zipl but it fails with: # zipl Using config file '/etc/zipl.conf' Building bootmap in '/boot' Building menu 'menu1' Adding #1: IPL section 'linux' (default) Preparing boot device: 09:00. Error: Could not read master boot record: Reached unexpected end of file where /boot is mounted thus: /dev/md1 ext3 97M 14M 79M 15% /mnt/tmp/boot Should I try to mount the actual partitions under boot sequentially? I am new to RAID and am not sure how to proceed. TIA -Robin -- -- Robin Atwood. "Ship me somewheres east of Suez, where the best is like the worst, Where there ain't no Ten Commandments an' a man can raise a thirst" from "Mandalay" by Rudyard Kipling -- -- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
