ZFS2 - Removing Drive

[Mitch0]

Wondering if someone might be able to give me some advice on removing and then later replacing a drive in my FreeNAS setup.

I have 5 drives in ZFS2.

One of the drives is reporting a SMART error - 72 offline uncorrectable sectors.

In Volume Status the drive in questions has a status of 'null' (rather than 'ONLINE' like the others).

I'm going to return this drive to the manufacturer (Seagate) for replacement but will have to wait for a new one to arrive.

Before I remove the drive I wondered if anyone knows if I am able to continue using the server without it or should I leave it off until I receive a replacement?

What will happen if I turn it off, remove the drive, and power back on without a replacement drive in it's place? Will this have any impact on my data? Would I then be OK to power off and install the replacement drive at a later date?

 

[Dusan]

Can you please post output of "zpool status"?

 

[Mitch0]

Code:

        NAME                                            STATE    READ WRITE CKS
UM                                                                             
        Files                                          ONLINE      0    0   
0                                                                             
          raidz2-0                                      ONLINE      0    0   
0                                                                             
            gptid/930816c5-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0   
0                                                                             
            gptid/93a6008f-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0   
0                                                                             
            gptid/942afa98-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0   
0                                                                             
            gptid/94a85f25-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0   
0                                                                             
            gptid/9527fbc9-774f-11e2-9d8b-902b3488cc77  ONLINE      31 4.15K   
0                                                                             
                                                                               
errors: No known data errors  

 

[Dusan]

The last drive is currently online but experiencing lot of write errors. Please follow the drive replacement procedure in the manual: http://doc.freenas.org/index.php/Volumes#Replacing_a_Failed_Drive.

Before I remove the drive I wondered if anyone knows if I am able to continue using the server without it or should I leave it off until I receive a replacement?

You can continue using it.

What will happen if I turn it off, remove the drive, and power back on without a replacement drive in it's place

Before physically removing the drive offline it via GUI (see the manual section linked above). When you power on without the drive it will show as UNAVAIL and the pool will be in DEGRADED state, but it will continue functioning.

Will this have any impact on my data?

Your data will be still accessible and as you used RAIDZ2 you will still have 1 drive redundancy (down from 2 drives redundancy).

Would I then be OK to power off and install the replacement drive at a later date?

Yes. After you install the new drive finish the replacement procedure.

 

[Mitch0]

Thank you for the advice, I appreciate it.

In the GUI when I go into 'Volume Status' the drive status contradicts the output of 'zpool status' and shows a status of null and there is no 'Offline' button.

It is also displaying an alert:

WARNING: The volume Files (ZFS) status is UNKNOWN: One or more devices has experienced an unrecoverable error. An attempt was made to correct the error. Applications are unaffected.Determine if the device needs to be replaced, and clear the errors using 'zpool clear' or replace the device with 'zpool replace'.

In the manual it states:

If there is no "Offline" button but only a "Replace" button, then the disk is already offlined and you can safely skip this step.

But I'm worried that the disk is not already offlined as it is showing as online when running 'zpool status'. Is it safe to skip this step given the uncertainty as to whether it is online/offline?

 

[Dusan]

In the GUI when I go into 'Volume Status' the drive status contradicts the output of 'zpool status' and shows a status of null and there is no 'Offline' button.

For some reason the GUI is not parsing the output of "zpool status" properly. Could you please post the entire zpool status output? The one you posted before is not complete.

But I'm worried that the disk is not already offlined as it is showing as online when running 'zpool status'. Is it safe to skip this step given the uncertainty as to whether it is online/offline?

The most important part of the GUI offline functionality is to switch off the swap partition on that drive (the system could panic if a swap device just dissappeared). However, this only really applies if you plan to "hot pull" the disk. If you shutdown the server and remove the disk you should be OK (the system only activates swap on partitions that are present at boot).

 

[joeschmuck]

Just one comment... Make sure you replace the correct drive. Verify it by the serial number.

 

[Mitch0]

For some reason the GUI is not parsing the output of "zpool status" properly. Could you please post the entire zpool status output? The one you posted before is not complete.

Apologies, I got it from the web GUI shell, didn't realise some was cut off as you can't scroll in there.

Code:

  pool: Files                                                                 
state: ONLINE                                                                 
status: One or more devices has experienced an unrecoverable error.  An       
        attempt was made to correct the error.  Applications are unaffected.   
action: Determine if the device needs to be replaced, and clear the errors     
        using 'zpool clear' or replace the device with 'zpool replace'.       
  see: http://www.sun.com/msg/ZFS-8000-9P                                     
  scan: none requested                                                         
config:                                                                       
                                                                               
        NAME                                            STATE    READ WRITE CKS
UM                                                                             
        Files                                          ONLINE      0    0   
0                                                                             
          raidz2-0                                      ONLINE      0    0   
0                                                                             
            gptid/930816c5-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0   
0                                                                             
            gptid/93a6008f-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0   
0                                                                             
            gptid/942afa98-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0   
0                                                                             
            gptid/94a85f25-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0   
0                                                                             
            gptid/9527fbc9-774f-11e2-9d8b-902b3488cc77  ONLINE      31 4.15K   
0                                                                             
                                                                               
errors: No known data errors  

The most important part of the GUI offline functionality is to switch off the swap partition on that drive (the system could panic if a swap device just dissappeared). However, this only really applies if you plan to "hot pull" the disk. If you shutdown the server and remove the disk you should be OK (the system only activates swap on partitions that are present at boot).

I was planning on shutting down to remove the drive anyway, so this should be OK?

Just one comment... Make sure you replace the correct drive. Verify it by the serial number.

Already got the serial number to hand, used to raise the return at Seagate and planned on checking it when removing, otherwise I have no idea which drive is which.

 

[Dusan]

I was planning on shutting down to remove the drive anyway, so this should be OK?

Yes.

Before you do that, could you please post the zpool status output again, but please increase the size of the Web Shell so that the lines do not wrap (there is a size dropdown next to the Paste button). It would be even better if you could get the output via SSH. Also please attach screenshot of the Volume Status screen.

 

[Mitch0]

Hopefully this is a bit better, from PuTTY:

Code:

  pool: Files
state: ONLINE
status: One or more devices has experienced an unrecoverable error.  An
        attempt was made to correct the error.  Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
        using 'zpool clear' or replace the device with 'zpool replace'.
  see: http://www.sun.com/msg/ZFS-8000-9P
  scan: none requested
config:
 
        NAME                                            STATE    READ WRITE CKSUM
        Files                                          ONLINE      0    0    0
          raidz2-0                                      ONLINE      0    0    0
            gptid/930816c5-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0    0
            gptid/93a6008f-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0    0
            gptid/942afa98-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0    0
            gptid/94a85f25-774f-11e2-9d8b-902b3488cc77  ONLINE      0    0    0
            gptid/9527fbc9-774f-11e2-9d8b-902b3488cc77  ONLINE      31 4.15K    0
 
errors: No known data errors