Hello all, I followed the wiki for removing one of my cache pool devices, as one of the drives was getting SMART errors. 

 

https://lime-technology.com/wiki/index.php/UnRAID_Manual_6#Removing_a_Device_from_a_Cache_Pool

 

Now I am getting a pop up notification:

 

unRAID Cache disk message: 24-02-2017 06:31 AM

Warning [ALEXANDRIA] - Cache pool BTRFS missing device(s)
KINGSTON_SH103S3240G_50026B722900A109 (sdc)

 

Any ideas? I followed the wiki steps exactly. 

post the output of:

 

btrfs fi show 

 

Forgot to say that it's normal for there to me a "device missing" error upon array start as the pool is balanced to a single device, if there activity on the cache device wait for it to finish and again with "btrfs fi show" to see if there are still missing devices.

 

@RobJ Can you still edit the Wiki? The FAQ contains a better way to remove a cache device, you could add to the wiki or link to the FAQ as you prefer.

 

root@Alexandria:~# btrfs fi show
Label: none  uuid: 13a9b951-9e48-442e-bd04-0ccf2570dbb5
        Total devices 1 FS bytes used 4.53TiB
        devid    1 size 4.55TiB used 4.55TiB path /dev/md1
Label: none  uuid: 3b381ffa-c144-429c-bbe9-f83b401f3821
        Total devices 1 FS bytes used 3.62TiB
        devid    1 size 3.64TiB used 3.64TiB path /dev/md2
Label: none  uuid: c78a7560-cb69-4a74-b42e-a614981759dd
        Total devices 1 FS bytes used 3.62TiB
        devid    1 size 3.64TiB used 3.63TiB path /dev/md3
Label: none  uuid: bdfc035e-e004-41eb-a182-d9b85fa2cf38
        Total devices 1 FS bytes used 2.69TiB
        devid    1 size 2.73TiB used 2.73TiB path /dev/md4
Label: none  uuid: 2b6e9fd4-37c5-4d97-8bcd-5b65bfe154a6
        Total devices 1 FS bytes used 2.69TiB
        devid    1 size 2.73TiB used 2.73TiB path /dev/md5
Label: none  uuid: 7bcba0a0-130b-439c-b41c-1f96b8db5a6b
        Total devices 1 FS bytes used 1.80TiB
        devid    1 size 1.82TiB used 1.82TiB path /dev/md6
Label: none  uuid: 4a9ce1e1-7a69-46dc-abe1-34d733d529a7
        Total devices 1 FS bytes used 1.78TiB
        devid    1 size 1.82TiB used 1.82TiB path /dev/md7
Label: none  uuid: ee101cce-a079-46ac-b58f-92504272583f
        Total devices 2 FS bytes used 129.00GiB
        devid    1 size 223.57GiB used 164.57GiB path /dev/sdc1
        *** Some devices missing
Label: none  uuid: ce66ada6-1a68-4dc0-a603-aa3dcea83699
        Total devices 1 FS bytes used 3.96GiB
        devid    1 size 20.00GiB used 7.27GiB path /dev/loop0
Label: none  uuid: 9d1b6e22-200c-4cec-a2fb-71fdbc68a719
        Total devices 1 FS bytes used 404.00KiB
        devid    1 size 1.00GiB used 126.38MiB path /dev/loop1
Label: none  uuid: 48de0e00-2ac6-45fa-8771-fb7c9635521b
        Total devices 1 FS bytes used 4.52TiB
        devid    1 size 4.55TiB used 4.56TiB path /dev/sde1

Here you go. Looks like there is a device missing for some reason, even though I followed the wiki. I will look at the FAQ to see how I should be doing it. 

Edited February 24, 20179 yr by ice pube
Woops - I think I messed up. I stopped the array and changed the devices to 1.

If the disk is still showing missing the FAQ steps will need some adjustment, if there's no activity (read/writes) on the cache device and it still shows a missing device, post output of:

 

btrfs device usage /mnt/cache

  and

btrfs filesystem df /mnt/cache

9 hours ago, johnnie.black said:

Forgot to say that it's normal for there to me a "device missing" error upon array start as the pool is balanced to a single device, if there activity on the cache device wait for it to finish and again with "btrfs fi show" to see if there are still missing devices.

 

@RobJ Can you still edit the Wiki? The FAQ contains a better way to remove a cache device, you could add to the wiki or link to the FAQ as you prefer.

 

 

I can still edit the wiki, but the part you reference is a part of the official documentation, which is supposed to only be written by Lime Technology staff, so I'm bringing jonp into this.

 

@jonp, johnnie.black has requested improvements in a wiki section that is part of the official docs, in the unRAID Manual, namely Removing a Device from a Cache Pool.  The FAQ entry he's talking about is How do I remove a cache pool disk?  What do you feel should be done here?  And what can we do to help?

 

6 hours ago, RobJ said:

I can still edit the wiki, but the part you reference is a part of the official documentation, which is supposed to only be written by Lime Technology staff, so I'm bringing jonp into this.

 

Sorry Rob, didn't realize it was part of the official docs, and that procedure works, in fact it's very similar so some of the other methods in the FAQ, but I find the other method cleaner and less prone to issues, especially if there's some issue with current pool, also no need to power down the server, but LT will decide if they want to change something.