Hi Leslie- Great use of overlays. I think this should work; I’ve “ported” degraded RAID6 arrays from LSI 92xx to MD a couple of times. I ended up having to use “—create —assume-clean” and guess at the DDF layout (I’ve seen both ddf-N-continue and ddf-N-restart, perhaps arrays created with different generations of LSI firmware?). It may be worth scanning the archives for “DDF”: https://marc.info/?l=linux-raid&w=2&r=1&s=ddf&q=b The one time I ran an LSI-created array under MD for a long time, I lost a drive and couldn’t figure out how to make MD find a spare and start the rebuild. The array was on its way out the door anyway, so I didn’t research or file a report; I imagine it was human error, but my understanding is MD DDF is not heavily used. If the array will be around a while, it’s probably best to get the data off the array and rebuild it as an MD native. > On Jan 30, 2019, at 8:18 AM, Leslie Rhorer <lrhorer@xxxxxxxxxxxx> wrote: > > Hello All, > > In the past, I was an active member of this forum, but I dropped off for a few years. I am back now because I have an issue with which I hope someone here can help me. I have a PC which has an LSI MegaRAID 9266-4i controller running RAID-5 on four drives, and unfortunately two of the four drives failed more or less simultaneously. One of the drives, however, was not completely dead, and with some time and a little babying, I was able to recover most of the important sections of one of the drives to a file using ddrescue. Unfortunately, I am having trouble getting the array to assemble properly after copying the file back to a drive using dd. > > I am hoping to be able to assemble the drive images under mdadm, but so far I am not getting the assembly to work, I think perhaps because not all the necessary information is available to mdadm during assembly. I created file images of both good drives and then I created loop devices from all three images and assembled using > > mdadm -A --force /dev/md7 /dev/loop0 /dev/loop1 /dev/loop2 > > > When I examine the array, I get: > > RAID-Server:/RAID/Server-Main/Temp# mdadm -D /dev/md7 > /dev/md7: > Version : ddf > Raid Level : container > Total Devices : 3 > > Working Devices : 3 > > Container GUID : 4C534920:20202020:1000005B:10009269:4974DEC4:0689B9A9 > (LSI 01/19/19 14:12:52) > Seq : 0000000b > Virtual Disks : 1 > > Member Arrays : > > Number Major Minor RaidDevice > > 0 7 1 - /dev/loop1 > 1 7 2 - /dev/loop2 > 2 7 0 - /dev/loop0 > > > Looking at the loop devices themselves I get: > > RAID-Server:/RAID/Server-Main/Temp# mdadm -E /dev/loop0 /dev/loop1 /dev/loop2 > /dev/loop0: > Magic : de11de11 > Version : 01.00.00 > Controller GUID : 4C534920:20202020:53563632:38343632:35370000:20300000 > (LSI SV62846257) > Container GUID : 4C534920:20202020:1000005B:10009269:4974DEC4:0689B9A9 > (LSI 01/19/19 14:12:52) > Seq : 0000000b > Redundant hdr : yes > Virtual Disks : 1 > > VD GUID[0] : 4C534920:20202020:1000005B:10009269:48421933:6EAADB6C > (LSI 05/31/18 22:36:19) > unit[0] : 0 > state[0] : Degraded, Consistent > init state[0] : Not Initialised > access[0] : Read/Write > Name[0] : > Raid Devices[0] : 4 (0@0K 1@0K 2@0K --@0K) > Chunk Size[0] : 1024 sectors > Raid Level[0] : RAID5 > Device Size[0] : 116686848 > Array Size[0] : 350060544 > > Physical Disks : 255 > Number RefNo Size Device Type/State > 0 b99f8876 116686848K /dev/loop0 active/Online > 1 b99f8877 116686848K active/Online > 2 b99f8878 116686848K active/Online > 3 b99f8879 116686848K active/Offline, Failed > /dev/loop1: > Magic : de11de11 > Version : 01.00.00 > Controller GUID : 4C534920:20202020:53563632:38343632:35370000:20300000 > (LSI SV62846257) > Container GUID : 4C534920:20202020:1000005B:10009269:4974DEC4:0689B9A9 > (LSI 01/19/19 14:12:52) > Seq : 0000000b > Redundant hdr : yes > Virtual Disks : 1 > > VD GUID[0] : 4C534920:20202020:1000005B:10009269:48421933:6EAADB6C > (LSI 05/31/18 22:36:19) > unit[0] : 0 > state[0] : Degraded, Consistent > init state[0] : Not Initialised > access[0] : Read/Write > Name[0] : > Raid Devices[0] : 4 (0@0K 1@0K 2@0K --@0K) > Chunk Size[0] : 1024 sectors > Raid Level[0] : RAID5 > Device Size[0] : 116686848 > Array Size[0] : 350060544 > > Physical Disks : 255 > Number RefNo Size Device Type/State > 0 b99f8876 116686848K active/Online > 1 b99f8877 116686848K /dev/loop1 active/Online > 2 b99f8878 116686848K active/Online > 3 b99f8879 116686848K active/Offline, Failed > /dev/loop2: > Magic : de11de11 > Version : 01.00.00 > Controller GUID : 4C534920:20202020:53563632:38343632:35370000:20300000 > (LSI SV62846257) > Container GUID : 4C534920:20202020:1000005B:10009269:4974DEC4:0689B9A9 > (LSI 01/19/19 14:12:52) > Seq : 0000000b > Redundant hdr : yes > Virtual Disks : 1 > > VD GUID[0] : 4C534920:20202020:1000005B:10009269:48421933:6EAADB6C > (LSI 05/31/18 22:36:19) > unit[0] : 0 > state[0] : Degraded, Consistent > init state[0] : Not Initialised > access[0] : Read/Write > Name[0] : > Raid Devices[0] : 4 (0@0K 1@0K 2@0K --@0K) > Chunk Size[0] : 1024 sectors > Raid Level[0] : RAID5 > Device Size[0] : 116686848 > Array Size[0] : 350060544 > > Physical Disks : 255 > Number RefNo Size Device Type/State > 0 b99f8876 116686848K active/Online > 1 b99f8877 116686848K active/Online > 2 b99f8878 116686848K /dev/loop2 active/Online > 3 b99f8879 116686848K active/Offline, Failed > > > The regular files look much the same: > > RAID-Server:/RAID/Server-Main/Temp# mdadm -E /RAID/Server-Main/Temp/LSI-RAID1 > /RAID/Server-Main/Temp/LSI-RAID1: > Magic : de11de11 > Version : 01.00.00 > Controller GUID : 4C534920:20202020:53563632:38343632:35370000:20300000 > (LSI SV62846257) > Container GUID : 4C534920:20202020:1000005B:10009269:4974DEC4:0689B9A9 > (LSI 01/19/19 14:12:52) > Seq : 0000000b > Redundant hdr : yes > Virtual Disks : 1 > > VD GUID[0] : 4C534920:20202020:1000005B:10009269:48421933:6EAADB6C > (LSI 05/31/18 22:36:19) > unit[0] : 0 > state[0] : Degraded, Consistent > init state[0] : Not Initialised > access[0] : Read/Write > Name[0] : > Raid Devices[0] : 4 (0@0K 1@0K 2@0K --@0K) > Chunk Size[0] : 1024 sectors > Raid Level[0] : RAID5 > Device Size[0] : 116686848 > Array Size[0] : 350060544 > > Physical Disks : 255 > Number RefNo Size Device Type/State > 0 b99f8876 116686848K active/Online > 1 b99f8877 116686848K active/Online > 2 b99f8878 116686848K active/Online > 3 b99f8879 116686848K active/Offline, Failed > Physical disks not in metadata!: > b99f8876 -unknown- > > > Does anyone have any advice? I suspect I will have to force the creation of an array, manually inputting the array parameters - assuming it can be made to work at all. I have multiple backups of the drive images, so I can fiddle all I want. >
