On 24/06/16 22:37, John Stoffel wrote: > > Another> Before attempting any recovery can I suggest that you get 4 x > Another> 2TB drives and dd the current drives so you have a backup. > > Not dd, dd_rescue instead. But yes, try to get new hardware and clone > all the suspect drives before you do anything else. Even just cloning > the most recently bad drive might be enough to get you going again. As I got told rather sharply :-) there's a big difference between dd and ddrescue. IFF dd completes successfully (it'll bomb on an error) then you have a "known good" copy. In other words the problem with dd is it won't work on a bad drive, but if it does work you're home and dry. ddrescue will ALWAYS work - but if it can't read a block it will leave an empty block in the copy! This is a bomb waiting to go off! In other words, ddrescue is great at recovering what you can from a damaged filesystem - less so at recovering a disk with a complicated setup on top. I know you're getting conflicting advice, but I'd try to get a good dd backup first. I don't know of any utility that will do an md integrity check on a ddrescue'd disk :-( so you'd need to do a fsck and hope ... Oh - and make sure you new disks are proper raid - eg WD Red or Seagate NAS. And are your current disks proper raid? If not, fix the timeout problem and your life *may* be made a lot simpler ... Have you got spare SATA ports? If not, go out and get an add-in card! If you can force the array to assemble, and create a temporary six-drive array (the two dud ones being assembled with the --replace option to move them to two new ones) that may be your best bet at recovery. If md can get at a clean read from three drives for each block, then it'll be able to rebuild the missing block. Cheers, Wol > > John > > > > Another> Then you can begin to think about performing the raid recovery in the > Another> knowledge you have a fallback position if it blows up. > > Another> Regards > > Another> Tony > > Another> On 24 June 2016 at 20:55, Peter Gebhard <pgeb@xxxxxxxxxxxxxx> wrote: >>> Hello, >>> >>> I have been asked to attempt data recovery on a RAID5 array which appears to have had two disk failures (in an array of four disks). I am gratefully hoping that some on this list could offer recommendations for my next steps. I have provided below the current state of the array per https://raid.wiki.kernel.org/index.php/RAID_Recovery. >>> >>> It appears from the output below that one of the disks (sdd1) failed last year and the admin did not notice this. Now, it appears a second disk (sdg1) has recently had read errors and was kicked out of the array. >>> >>> Should I try to restore the array using the recreate_array.pl script provided on the RAID_Recovery site? Should I then try to recreate the array and/or perform ‘fsck’? >>> >>> Thank you greatly in advance! >>> >>> raid.status: >>> >>> /dev/sdd1: >>> Magic : a92b4efc >>> Version : 1.2 >>> Feature Map : 0x0 >>> Array UUID : bfb03f95:834b520d:60f773d8:ecb6b9e3 >>> Name : <->:0 >>> Creation Time : Tue Nov 29 17:33:39 2011 >>> Raid Level : raid5 >>> Raid Devices : 4 >>> >>> Avail Dev Size : 3907024896 (1863.01 GiB 2000.40 GB) >>> Array Size : 5860535808 (5589.04 GiB 6001.19 GB) >>> Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB) >>> Data Offset : 2048 sectors >>> Super Offset : 8 sectors >>> State : clean >>> Device UUID : ec1a6336:0a991298:5b409bf1:4585ccbe >>> >>> Update Time : Sun Jun 7 02:28:00 2015 >>> Checksum : f9323080 - correct >>> Events : 96203 >>> >>> Layout : left-symmetric >>> Chunk Size : 512K >>> >>> Device Role : Active device 0 >>> Array State : AAAA ('A' == active, '.' == missing) >>> >>> /dev/sde1: >>> Magic : a92b4efc >>> Version : 1.2 >>> Feature Map : 0x0 >>> Array UUID : bfb03f95:834b520d:60f773d8:ecb6b9e3 >>> Name : <->:0 >>> Creation Time : Tue Nov 29 17:33:39 2011 >>> Raid Level : raid5 >>> Raid Devices : 4 >>> >>> Avail Dev Size : 3907024896 (1863.01 GiB 2000.40 GB) >>> Array Size : 5860535808 (5589.04 GiB 6001.19 GB) >>> Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB) >>> Data Offset : 2048 sectors >>> Super Offset : 8 sectors >>> State : clean >>> Device UUID : ed13b045:ca75ab96:83045f97:e4fd62cb >>> >>> Update Time : Sun Jun 19 19:43:31 2016 >>> Checksum : bb6a905f - correct >>> Events : 344993 >>> >>> Layout : left-symmetric >>> Chunk Size : 512K >>> >>> Device Role : Active device 3 >>> Array State : .A.A ('A' == active, '.' == missing) >>> >>> /dev/sdf1: >>> Magic : a92b4efc >>> Version : 1.2 >>> Feature Map : 0x0 >>> Array UUID : bfb03f95:834b520d:60f773d8:ecb6b9e3 >>> Name : <->:0 >>> Creation Time : Tue Nov 29 17:33:39 2011 >>> Raid Level : raid5 >>> Raid Devices : 4 >>> >>> Avail Dev Size : 3907024896 (1863.01 GiB 2000.40 GB) >>> Array Size : 5860535808 (5589.04 GiB 6001.19 GB) >>> Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB) >>> Data Offset : 2048 sectors >>> Super Offset : 8 sectors >>> State : clean >>> Device UUID : a1ea11e0:6465fe26:483f133d:680014b3 >>> >>> Update Time : Sun Jun 19 19:43:31 2016 >>> Checksum : 738493f3 - correct >>> Events : 344993 >>> >>> Layout : left-symmetric >>> Chunk Size : 512K >>> >>> Device Role : Active device 1 >>> Array State : .A.A ('A' == active, '.' == missing) >>> >>> /dev/sdg1: >>> Magic : a92b4efc >>> Version : 1.2 >>> Feature Map : 0x0 >>> Array UUID : bfb03f95:834b520d:60f773d8:ecb6b9e3 >>> Name : <->:0 >>> Creation Time : Tue Nov 29 17:33:39 2011 >>> Raid Level : raid5 >>> Raid Devices : 4 >>> >>> Avail Dev Size : 3907024896 (1863.01 GiB 2000.40 GB) >>> Array Size : 5860535808 (5589.04 GiB 6001.19 GB) >>> Used Dev Size : 3907023872 (1863.01 GiB 2000.40 GB) >>> Data Offset : 2048 sectors >>> Super Offset : 8 sectors >>> State : active >>> Device UUID : a9737439:17f81210:484d4f4c:c3d34a8a >>> >>> Update Time : Sun Jun 19 12:18:49 2016 >>> Checksum : 9c6d24bf - correct >>> Events : 343949 >>> >>> Layout : left-symmetric >>> Chunk Size : 512K >>> >>> Device Role : Active device 2 >>> Array State : .AAA ('A' == active, '.' == missing) >>> >>> -- >>> 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 > Another> -- > Another> To unsubscribe from this list: send the line "unsubscribe linux-raid" in > Another> the body of a message to majordomo@xxxxxxxxxxxxxxx > Another> 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 > -- 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
