Re: Question: array locking, possible?
It looks like we are the only two md users interested in such a feature. Not enough to get Neil's attention ;-) Regards, Chris On Wed, 8 Feb 2006 21:45:33 +0100 Jure Peèar [EMAIL PROTECTED] wrote: On Wed, 8 Feb 2006 11:55:49 +0100 Chris Osicki [EMAIL PROTECTED] wrote: I was thinking about it, I have no idea how to do it on Linux if ever possible. I connect over fibre channel SAN, using QLogic QLA2312 HBAS, if it matters. Anyone any hints? I too am running a jbod with md raid between two machines. So far md never caused any kind of problems, altough I did have situations where both machines were syncing mirrors at once. If there's a little tool to reserve a disk via scsi, I'd like to know about it too. Even a piece of code would be enough. -- Jure Peèar http://jure.pecar.org/ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: create a partial raid5
Oh yeah, it's possible - I've done it in connection with disaster recovery (or rather, attempt thereof). The key is to write 'missing' instead of the device name, so you just go mdadm -C /dev/md0 --raid-level=5 --raid-devices=3 /dev/hdxx /dev/hdyy missing -note that the missing drive can be anywhere you like. Regards, Troels On Feb 9, 2006, at 12:40 , stephan sperber wrote: Hello! Is it possible to create a Radi5 with only 2 disks? (I know that Raid5 needs 3 to be really redundant) With a Raid1 I can do things like: mdadm -C /dev/md0 --force --raid-devices=1 /dev/hdb2 mkreiserfs /dev/md0 copy files from an older drive to the raid, get the old drive out and put the new disk for the raid in. then mdadm -G /dev/md0 --raid-disks=2 mdadm -a /dev/md0 /dev/hdc2 and the raid1 is now a real raid1 (after sync) It would be great to have something similar for raid5: mdadm -C /dev/md0 --force --raid-devices=2 /dev/hdb2 /dev/hdc2 mdadm -G /dev/md0 --raid-disks=3 mdadm -a /dev/md0 /dev/hda2 or mdadm -C /dev/md0 --force --fail=/dev/hda2 --raid-devices=3 /dev/ hdb2 / dev/hdc2 mdadm -a /dev/md0 /dev/hda2 i know that this is possible with raidtools and /etc/raidtab. is this possible with the recent version of mdadm or is it a planned feature (or not planned)? thanks in advance stephan -- Telefonieren Sie schon oder sparen Sie noch? NEU: GMX Phone_Flat http://www.gmx.net/de/go/telefonie - To unsubscribe from this list: send the line unsubscribe linux- raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Kernels and MD versions (was: md: Introduction - raid5 reshape mark-2)
Hello Patrik , On Wed, 8 Feb 2006, Patrik Jonsson wrote: Neil Brown wrote: I always make them against the latest -mm kernel, so that would be a good place to start. However things change quickly and I can't promise it will apply against whatever is the 'latest' today. If you would like to nominate a particular recent kernel, I'll create a patch set that is guaranteed to apply against that. (Testing is always appreciated, and well worth that small effort on my part). I find this is a major problem for me, too. Even though I try to stay up to date with the md developments, I have a hard time piecing together which past patches went with which version, so if I get a recent version I don't know which patches need to be applied and which are already in there. My suggestion is that Neil, should he be willing, keep a log somewhere which detail kernel version and what major updates in md functionality go along with it. Something like 2.6.14 raid5 read error correction 2.6.15 md /sys interface 2.6.16.rc1 raid5 reshape 2.6.16.rc2-mm4 something else cool it would include the released kernels and the previews of the current kernel. That way, say I see that the latest FC4 kernel is 2.6.14, I could look and see that since the raid5 read error correction was included, I don't have to go looking for the patches. Maybe this is too much hassle (or maybe it's already out there somewhere) but I'm thinking simple, and I think it would give a high-level overview of the development for us who are not intimately involved in every kernel version. Iirc , The git/snv/cvs repositories 'can' contain this information . Neil (as you say , if willing) can pull the kernel versions Notes for his submissions from the repository . Hth , JimL -- +--+ | James W. Laferriere | SystemTechniques | Give me VMS | | NetworkEngineer | 3542 Broken Yoke Dr. | Give me Linux | | [EMAIL PROTECTED] | Billings , MT. 59105 | only on AXP | | http://www.asteriskhelpdesk.com/cgi-bin/astlance/r.cgi?babydr | +--+ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: Question: array locking, possible?
There is more interest, just not vocal. May want to look at LVM2 and its ability to use tagging to control enablement of VGs. This way it is not HW dependent. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chris Osicki Sent: Thursday, February 09, 2006 2:26 AM To: linux-raid@vger.kernel.org Subject: Re: Question: array locking, possible? It looks like we are the only two md users interested in such a feature. Not enough to get Neil's attention ;-) Regards, Chris On Wed, 8 Feb 2006 21:45:33 +0100 Jure Peèar [EMAIL PROTECTED] wrote: On Wed, 8 Feb 2006 11:55:49 +0100 Chris Osicki [EMAIL PROTECTED] wrote: I was thinking about it, I have no idea how to do it on Linux if ever possible. I connect over fibre channel SAN, using QLogic QLA2312 HBAS, if it matters. Anyone any hints? I too am running a jbod with md raid between two machines. So far md never caused any kind of problems, altough I did have situations where both machines were syncing mirrors at once. If there's a little tool to reserve a disk via scsi, I'd like to know about it too. Even a piece of code would be enough. -- Jure Peèar http://jure.pecar.org/ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Question: array locking, possible?
On Thu, Feb 09, 2006 at 10:28:58AM -0800, Stern, Rick (Serviceguard Linux) wrote: There is more interest, just not vocal. May want to look at LVM2 and its ability to use tagging to control enablement of VGs. This way it is not HW dependent. I believe there is space in md1 superblock for a cluster/exclusive flag, if not the name field could be used what is missing is an interface between mdadm and cmcld so mdadm can ask cmcld permission to activate an array with the cluster/exclusive flag set. L. -- Luca Berra -- [EMAIL PROTECTED] Communication Media Services S.r.l. /\ \ / ASCII RIBBON CAMPAIGN XAGAINST HTML MAIL / \ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Question: array locking, possible?
On Thursday February 9, [EMAIL PROTECTED] wrote: It looks like we are the only two md users interested in such a feature. Not enough to get Neil's attention ;-) :-) Just because I haven't said anything doesn't mean I'm not listening. Cluster awareness is definitely on my radar. I have no firm plans yet but I'm certainly interested in understanding the issues. So I'm listening.. NeilBrown - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
