RAID0 uses all disks evenly (all 2 in your case). I don?t see how you can recover from a drive failure with a RAID0. Never use RAID0 unless you are willing to lose all the data! Are you sure the second disk is dead? Have you done a read test on the disk? dd works well for read testing. Try this: dd if=/dev/hdb2 of=/dev/null bs=64k or dd if=/dev/hdb of=/dev/null bs=64k Guy } -----Original Message----- } From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- } owner@xxxxxxxxxxxxxxx] On Behalf Of Technomage } Sent: Wednesday, March 29, 2006 12:09 AM } To: linux-raid@xxxxxxxxxxxxxxx } Subject: recovering data on a failed raid-0 installation } } ok, } here's the situation in a nutshell. } } one of the 2 HD's in a linux raid-0 installation has failed. } } Fortunately, or otherwise, it was NOT the primary HD. } } problem is, I need to recover data from the first drive but appear to be } unable to do so because the raid is not complete. the second drive only } had } 193 MB written to it and I am fairly certain that the data I would like to } recover is NOT on that drive. } } can anyone offer any solutions to this? } } the second HD is not usable (heat related failure issues). } } The filesystem used on the md0 partition (under mdadm) was xfs. now I have } tried the xfs_check and xfs_repair tools and they are not helpful at this } point. } } The developer (of mdadm) suggested I use the following commands in an } attempt } to recover: } } mdadm -C /dev/md0 -l0 -n2 /dev/...... } fsck -n /dev/md0 } } However, the second one was a no go. } } I am stumped as to how to proceed here. I need the data off the first } drive, } but do not appear to have any way (other than using cat to see it) to get } at } it. } } some help would be greatly appreciated. } } technomage } } p. here is the original response sent back to me from the developer of } mdadm: } *************************** } Re: should have been more explicit here -> Re: need some help <URGENT!> } From: Neil Brown <neilb@xxxxxxx> } To: Technomage <technomage-hawke@xxxxxxx> } Date: Sunday 22:01:45 } On Sunday March 26, technomage-hawke@xxxxxxx wrote: } > ok, } > } > you gave me more info than some local to that mentioned e-mail list. } > } > ok, the vast majority of the data I need to recover is on /dev/hda } > and /dev/hdb only has 193 MB and is probably irrelevant. } > } > can you help me with this? } > can you baby me through this. I really need to recover this data (if at } all } > possible). } } Not really, and certainly not now (I have to go out). } I have already make 2 suggestions } mail linux-raid@xxxxxxxxxxxxxxx } and } mdadm -C /dev/md0 -l0 -n2 /dev/...... } fsck -n /dev/md0 } } try one of those. } } NeilBrown } } > } > the friend of mine that this actually happened to is on the phone, } begging } me } > and grovelling before the gods of linux in order to have this fixed. I } have } > setup an identical test situation here. } > } > the important data is on drive 1 and drive 2 is mostly irrelevant. } > is there any way to convince raid-0 to truncate to the end of drive 1 } and } > allow me to get whatever data I can off. btw, the filesystem that was } > formatted was xfs (for linux) on md0. } > } > if you have questions, please do not hesitate to ask. } > } > thank you. } > } > p. real name here is Eric. } > } > } > On Sunday 26 March 2006 21:33, you wrote: } > > On Sunday March 26, technomage-hawke@xxxxxxx wrote: } > > } > > With a name like "Technomage" and a vague subject "need some help } > > <URGENT>", I very really discarded your email assuming it was spam! } > > } > > Questions like this are best sent to linux-raid@xxxxxxxxxxxxxxxx } > > } > > If one drive in a raid0 has failed non-recoverably, then half your } > > data is gone, so you are out of luck. } > > } > > Your best bet would be to recreate the raid0 in exactly the same } > > configuration as before, and see if you can find the data there. } > > e.g. } > > mdadm -C /dev/md0 -l0 -n2 /dev/hda2 /dev/hdb2 } > > fsck -n /dev/md0 } > > } > > or something like that. } > > } > > NeilBrown } > > } > > > I recently ran into a problem after an install using mdadm. the } software } > > > raid-0 environment suffered a failure after a HD in the system } failed } due } > > > to thermal run-away. } > > > } > > > the setup goes like this: } > > > } > > > /dev/hda has: } > > > /dev/hda1 -> boot (512 MN) } > > > /dev/hda2 -> partition 1 (linux raid autodetect) } > > > } > > > /dev/hdb has: } > > > /dev/hdb1 -> swap (512 MB) } > > > /dev/hdb2 -> partition 2 (linux raid autodetect) } > > > } > > > /dev/hdb is the drive that failed. according to a drive imager, only } 129 } > > > MB of data was actually written to the second raid partition (in } serial). } > > > unfortunately, without it, I cannot recover any data off of the } first HD } > > > and I would like very much to do so. Some of this data is for my } work as } > > > a forensics examiner. } > > > } > > > I am fairly certain that the data I need to recover is on /dev/hda } but } so } > > > far, I have been unable to read the data in any meaningful way } (except } > > > the use of cat piped through less to see if the data is, in fact, } > > > readable). } > > > } > > > can you help? } > > > } > > > thank you. } - } 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 - 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
