thanks for the input but:

"only inactive hot spares can be removed", whereas I need to
remove/detach/whatever one disk of a raidz1 pool, no mirrors, no duplicates.

I get the impression there is no way to do that, so I might have to
build the pool from scratch again, am I right?



On 29.10.14 09:49, ilove...@icloud.com wrote:
> zpool attach makes a non-mirror into a mirror. zpool detach makes a mirror 
> into a non-mirror.
> 
> I believe you are looking for zpool remove.
> 
> On Wednesday, October 29, 2014 12:54:48 AM UTC-7, Busty wrote:
>>
>> Wow, thanks Bjoern for that, now I really know what was going on. I 
>> really appreciate the time you took to explain all that. 
>>
>> The problem I'm facing is, that I can't detach the drive. A "zpool 
>> detach pool diskx" gives me the error: 
>> "cannot detach diskx: only applicable to mirror and replacing vdevs." 
>>
>> I managed to format the disk as hfs+, zero the drive completely and 
>> then format as zfs, but zfs still considers this disk as one of the pool. 
>>
>> What can I do to get the drive out of the pool? 
>>
>> On 26.10.14 14:43, Bjoern Kahl wrote: 
>>>
>>> (this is going to be a bit longer, but since it is a reappearing 
>>> topic I'd like to provide some background information on what 
>>> happens behind the scene) 
>>>
>>>
>>> Am 26.10.14 um 12:09 schrieb 'Busty' via zfs-macos: 
>>>> This generated a follow up question: 
>>>
>>>> I did the zpool replace with an unformatted disk as described in 
>>>> the oracle documentation. After that, zpool status showed the 
>>>> disk as part of the pool, but as "disk2", not as "disk2s2". 
>>>> Accordingly, OSX wanted to initialize the disk every time upon 
>>>> booting. 
>>>
>>>> So I formatted the disk as described in the getting started 
>>>> guide on MacZFS, which resolves the problem of OSX wanting to 
>>>> initialize the disk, but still it shows as "disk2" (without the 
>>>> s2) with zpool status. I was prepared to resilver the disk again 
>>>> after that, but it was still part of the pool. 
>>>
>>>> I started a scrub, had 6 checksum errors on that disk right at 
>>>> the beginning, but otherwise the scrub seems to consider the data 
>>>> as good. It is at 7 percent right now. 
>>>
>>>> Should I be worried that the data is not integer? 
>>>
>>> Yes, you should. 
>>>
>>> You basically did the following: 
>>>
>>> 1) 
>>>
>>> Gave a whole disk to ZFS, telling it, it is OK to use the whole 
>>> space from first to last block of the disk. 
>>>
>>> ZFS did so and started writing data: 
>>>
>>> a) it's vdev label 0,1 from block 0 to 1023 (assuming 512 byte 
>>> blocks) 
>>>
>>> b) it's vdev label 2,3 from block N-1024 to N-1 (assuming N block 
>>> on disk) 
>>>
>>> c) your pool data in between, following it's somewhat complex 
>>> allocation scheme 
>>>
>>>
>>> 2) 
>>>
>>> Told OS X to write a disk label (aka GPT) on the disk. 
>>>
>>> OS X did so and started writing data: 
>>>
>>> a) A protective MBR in block 0 -> no damage, ZFS anticipates that, 
>>> leaving block 0 to 32 (16k) of its label alone. 
>>>
>>> b) The primary GPT structures, starting from block 1 (byte 
>>> position 512) to end of block 33 (byte position 17408). This 
>>> trashed part of the configuration dictionary in vdev label 0 
>>>
>>> c) The secondary GPT structures, in the last 17408 bytes of the 
>>> disk, overwriting part of the uberblock array in vdev label 3. 
>>>
>>> d) The Mac OS X EFI area, usually around block 40 to 409600 (byte 
>>> positions up to 200 MB). This is "/dev/diskXs1". 
>>>
>>> e) The man partition "/dev/diskXs2", roughly starting at block 
>>> 409640 and extending until some blocks before the secondary GPT 
>>> structures. This is just created but nor written in "noformat" has 
>>> been used. 
>>>
>>>
>>>
>>> What does this mean? -------------------- 
>>>
>>>
>>> It depends on how ZFS sees the disk.  Most likely it will continue 
>>> to use "diskX" (no slice).  In that case: 
>>>
>>> The pool keeps functioning, since vdev labels 1 and 2 are undamaged 
>>> (0 and 3 are overwritten, see above) 
>>>
>>> ZFS will almost instantly fix it's labels, completely overwriting 
>>> the secondary GPT.  Mac OS X doesn't care, it writes the secondary 
>>> GPT and never looks there again. 
>>>
>>> The situation on the is start is more complex. 
>>>
>>> ZFS will also almost instantly fix its label 0. However, this 
>>> writes only from block 32 on (byte position 16384 onwards), since 
>>> it completely ignores the first 16 blocks (supposed to hold disk 
>>> identifier) and doesn't touch the next 16 in normal operation, 
>>> since they are supposed to hold ZFS boot code and are unused in 
>>> current implementations. 
>>>
>>> So the rewritten vdev label 0 trashes the last 512 bytes of the 
>>> primary GPT.  This does concern Mac OS X and you should see a 
>>> waring about an invalid GPT CRC in the system log after boot. 
>>>
>>>
>>> So much for the administrative data structures.  What about your 
>>> data? 
>>>
>>> ZFS' data area starts after the vdev label 1, i.e. at block 1024 
>>> (byte position 512 kB).  This is somewhere inside the EFI area, 
>>> overwriting whatever Mac OS X placed there (depends on version, 
>>> older Mac OS X version didn't placed anything there, don't know for 
>>> newer versions).  In any case, Mac OS X does not access the EFI 
>>> area in normal operation, and so won't note the damage. 
>>>
>>> On the other hand, Mac OS X is initializing the EFI area when 
>>> initializing a disk, placing an empty FAT file system there. 
>>>
>>> This FAT overwrites part of the ZFS pool data and caused the 
>>> checksum errors. 
>>>
>>>
>>> What to do now? --------------- 
>>>
>>> I would detach the disk in question, zap the first and last several 
>>> MB of disk space (i.e. of diskX itself, not of the diskX2s slice) 
>>> by writing zero bytes to disk, for example using "dd", reformat 
>>> with diskutil and reattach as /dev/diskX2s. 
>>>
>>> Another approach for zapping the disk content is, to format as 
>>> HFS+ with diskutil and then select "clear/erase free disk space" 
>>> (or whatever the English button label says). 
>>>
>>>
>>> Best regards 
>>>
>>> Björn 
>>>
>>>> On 23.10.14 14:01, 'Busty' via zfs-macos wrote: 
>>>
>>>>> This was in fact easier than I thought. What did the trick was 
>>>>> to physically swap the faulty disk with a new one and then 
>>>>> "zpool detach (faulty disk)" 
>>>>>
>>>>> After that a "zpool replace" went like a charm. 
>>>>>
>>>>> Problem solved. 
>>>>>
>>>>> On 15.10.14 20:32, 'Busty' via zfs-macos wrote: 
>>>>>> In my pool, I had a disk that got a smart error (bad block), 
>>>>>> so I pulled it out, installed a new one and made a "zpool 
>>>>>> replace disk5s2 806745480046791602". (That number was shown 
>>>>>> when typing "zpool status" as the missing device.) 
>>>>>>
>>>>>> The resilver process started, but it seems that the new disk 
>>>>>> is faulty, because it disappears from the device list 
>>>>>> infrequently, but still at least every 6 hours (I have 
>>>>>> Temperature Monitor running which shows me all disks by 
>>>>>> serial number). 
>>>>>>
>>>>>> So I want to change it. But zpool detach <poolname> 
>>>>>> dev/disk5s2 gives the error "no such device in pool". 
>>>>>>
>>>>>> How can I abort the resilvering process? Or is there another 
>>>>>> way to restart the resilvering with a new disk? 
>>>>>>
>>>>>> The original disk with the bad block is already on its way 
>>>>>> to Western Digital (it was still in warranty). 
>>>
>>>
>>>
>>
> 

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