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HI, Gentooers! |
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|
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So, I typed dd if=/dev/zero of=/dev/sd<wrong letter>, and despite |
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hitting ctrl-c quite quickly, zeroed out some portion of the initial |
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part of a disk. Which did this to my zfs raidz3 array: |
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|
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NAME STATE READ WRITE CKSUM |
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zfs DEGRADED 0 0 0 |
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raidz3-0 DEGRADED 0 0 0 |
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ata-HGST_HUS724030ALE640_PK1234P8JJJVKP ONLINE 0 0 0 |
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ata-HGST_HUS724030ALE640_PK1234P8JJP3AP ONLINE 0 0 0 |
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ata-ST4000NM0033-9ZM170_Z1Z80P4C ONLINE 0 0 0 |
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ata-ST4000NM0033-9ZM170_Z1ZAZ8F1 ONLINE 0 0 0 |
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14296253848142792483 UNAVAIL 0 0 |
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0 was /dev/disk/by-id/ata-ST4000NM0033-9ZM170_Z1ZAZDJ0-part1 |
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ata-ST4000NM0033-9ZM170_Z1Z80KG0 ONLINE 0 0 0 |
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|
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Could have been worse. I do have backups, and it is raid3, so all |
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I've injured is my pride, but I do want to fix things. I'd |
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appreciate some guidance before I attempt doing this - I have no |
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experience at it myself. |
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|
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The steps I envision are |
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|
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1) zpool offline zfs 14296253848142792483 (What's that number?) |
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2) do something to repair the damaged disk |
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3) zpool online zfs <repaired disk> |
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|
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Right now, the device name for the damaged disk is /dev/sda. Gdisk |
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says this about it: |
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|
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Caution: invalid main GPT header, but valid backup; regenerating main header |
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from backup! |
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|
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Warning: Invalid CRC on main header data; loaded backup partition table. |
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Warning! Main and backup partition tables differ! Use the 'c' and 'e' options |
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on the recovery & transformation menu to examine the two tables. |
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|
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Warning! Main partition table CRC mismatch! Loaded backup partition table |
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instead of main partition table! |
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|
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Warning! One or more CRCs don't match. You should repair the disk! |
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Main header: ERROR |
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Backup header: OK |
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Main partition table: ERROR |
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Backup partition table: OK |
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|
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Partition table scan: |
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MBR: not present |
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BSD: not present |
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APM: not present |
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GPT: damaged |
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|
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Found invalid MBR and corrupt GPT. What do you want to do? (Using the |
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GPT MAY permit recovery of GPT data.) |
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1 - Use current GPT |
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2 - Create blank GPT |
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|
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Your answer: ( I haven't given one yet) |
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|
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I'm not exactly sure what this is telling me. But I'm guessing it |
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means that the main partition table is gone, but there's a good |
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backup. In addition, some, but not all disk id info is gone: |
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1) /dev/disk/by-id still shows ata-ST4000NM0033-9ZM170_Z1ZAZDJ0 (the |
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damaged disk) but none of its former partitions |
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2) /dev/disk/by-partlabel shows entries for the undamaged disks in the |
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pool, but not the damaged one |
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3) /dev/disk/by-partuuid similar to /dev/disk/by-partlabel |
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4) /dev/disk/by-uuid does not show the damaged disk |
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|
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This particular disk is from a batch of 4 I bought with the same make |
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and specification and very similar ids (/dev/disk/by-id). Can I |
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repair this disk by copying something off one of those other disks |
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onto this one? Is repair just repartitioning - as in the Gentoo |
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handbook? Is it as simple as running gdisk and typing 1 to accept |
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gdisk's attempt at recovering the gpt? Is running gdisk's recovery |
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and transformation facilities the way to go (the b option looks like |
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it's made for exactly this situation)? |
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|
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Anybody experienced at this and willing to guide me? |
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|
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Thanks, |
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|
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John Blinka |