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Veritas Access Troubleshooting Guide

Last Published: 2021-02-14

Product(s): Access (7.4.2)

Platform: Linux

Replacing a disk

In some cases, you may need to replace an existing disk. This section describes the steps for replacing a disk.

Note:

You can replace a disk in a storage pool from a master or a subordinate node. From a Cluster Volume Manager (CVM) master node, you can replace DAS and SAN disks. From a subordinate node, you can replace only DAS disks.

To replace a disk

Remove the disk that needs to be replaced from the array side.
Add the new disk to the system from the array side.
Run the following command on all the nodes in the cluster to eliminate the old disk from the Veritas Volume Manager (VxVM) view.
```
#vxdisk rm <old-disk-name>
```
Run the following command on the node for which you want to replace the disk.
```
# vxdisk scandisks
```
Initialize the new disk that has been added to the cluster by using the vxdisksetup command.
```
#/etc/vx/bin/vxdisksetup  - fi <new-disk-name>
```
Apply the tag to the newly added device that is similar to the Veritas Access pool name on the node where the failed disk resides.
```
# vxdisk settag site=<pool-name> <new-disk-name>
```
Run the vxdiskadm command and choose option #5 to replace a failed disk with a new disk on the node where the failed disk resides.
```
#vxdiskadm
```
Note:
If the disk replacement is triggered from a subordinate node, the vxrecover command fails.
If the disk replacement is triggered from a subordinate node, run the following command from the slave node for all the affected volumes.
```
#vxrecover  - b  - c  - s <vol-name>
```

Rename the newly added disk to the disk access name.

#vxedit  - g <dg-name> rename <old-disk-name> <new-disk-name>

Rename the subdisks as per the newly added disk name.

#vxedit  - g <dg-name> rename <old-subdisk-name> <new-subdisk-name>

Example: Disk replacement from a CVM master node

This example describes the procedure for replacing the emc0_2255 disk with emc0_2263 disk. The emc0_2263 disk has been excluded and it is added later to simulate the disk addition.

Replacing a disk from a CVM master node

Run the vxdmpadm exclude command to remove the emc0_2255 disk.
```
# vxdmpadm exclude dmpnodename=emc0_2255
```
Run the the vxdmpadm include command to include the emc0_2263 disk.
```
# vxdmpadm include dmpnodename=emc0_2263
```
Note:
You can run the vxdisk scandisks command to scan the disks.
Run the settag command to apply the tag to the underlying disk.
```
# vxdisk settag emc0_2263 tag=pool1
```

Run the vxdiskadm command and choose option #5 to replace the failed disk.

[root@fss7310_01 ~]# vxdiskadm
Volume Manager Support Operations
Menu:: VolumeManager/Disk
1 Add or initialize one or more disks
2 Encapsulate one or more disks
3 Remove a disk
4 Remove a disk for replacement 5 Replace a failed or removed disk
6 Mirror volumes on a disk
7 Move volumes from a disk
8 Enable access to (import) a disk group
9 Remove access to (deport) a disk group
10 Enable (online) a disk device
11 Disable (offline) a disk device
12 Mark a disk as a spare for a disk group
13 Turn off the spare flag on a disk
14 Unrelocate subdisks back to a disk
15 Exclude a disk from hot-relocation use
16 Make a disk available for hot-relocation use
17 Prevent multipathing/Suppress devices from VxVM's view
18 Allow multipathing/Unsuppress devices from VxVM's view
19 List currently suppressed/non-multipathed devices
20 Change the disk naming scheme
21 Change/Display the default disk layouts
22 Dynamic Reconfiguration Operations
list List disk information

Select an operation to perform: 5

Replace a failed or removed disk
Menu:: VolumeManager/Disk/ReplaceDisk

Use this menu operation to specify a replacement disk for a disk
that you removed with the "Remove a disk for replacement" menu
operation, or that failed during use. You will be prompted for
a disk name to replace and a disk device to use as a replacement.
You can choose an uninitialized disk, in which case the disk will
be initialized, or you can choose a disk that you have already
initialized using the Add or initialize a disk menu operation.

Select a removed or failed disk [<disk>,list,q,?] list
Disk group: sfsdg
DM NAME DEVICE TYPE PRIVLEN PUBLEN STATE
dm emc0_2255 - - - - NODEVICE

Select a removed or failed disk [<disk>,list,q,?] emc0_2255

The following devices are available as replacements:
emc0_2263
You can choose one of these devices to replace emc0_2255. 
Choose "none" to initialize another device to replace emc0_2255.
Choose a device, or select "none" [<device>,none,q,?] 
(default: emc0_2263) emc0_2263
VxVM INFO V-5-2-382
The requested operation is to use the initialized device emc0_2263
to replace the removed or failed disk emc0_2255 in disk group sfsdg.
Continue with operation? [y,n,q,?] (default: y) y
Use FMR for plex resync? [y,n,q,?] (default: n)
VxVM INFO V-5-2-282 Replacement of disk emc0_2255 in group 
sfsdg with disk device emc0_2263 completed successfully.
Replace another disk? [y,n,q,?] (default: n)

Rename the disk as per the disk access name to avoid the vxdg issue.

# vxedit -g sfsdg rename emc0_2255 emc0_2263

# vxdisk list | grep emc0_2263 emc0_2263 auto:cdsdisk emc0_2263 
sfsdg online shared

Rename the subdisks as per disk access name.

# vxedit -g sfsdg rename emc0_2255-03 emc0_2263-03
# vxedit -g sfsdg rename emc0_2255-02 emc0_2263-02

[root@fss7310_01 ~]# vxprint -pvs | grep -i 2263
sd emc0_2263-02 vol1-P01 ENABLED 699136 0 - - -
sd emc0_2263-03 vol1_dcl-01 ENABLED 67840 0 - - -
[root@fss7310_01 ~]# vxprint -pvs | grep -i 2255
[root@fss7310_01 ~]#

Example: Disk replacement from a subordinate node

This example describes the procedure for replacing the emc0_2273 disk with emc0_2305 disk. The emc0_2263 disk has been excluded and it is added later to simulate the disk addition.

To replace a disk from a subordinate node

Run the vxdmpadm exclude command to remove the emc0_2273 disk.
```
# vxdmpadm exclude dmpnodename=emc0_2273
```
Run the vxdmpadm include command to include the emc0_2305 disk.
```
# vxdmpadm include dmpnodename=emc0_2305
```
Note:
You can run the vxdisk scandisks command to scan the disks.
Run the vxdisk rm command from the remaining nodes in the cluster:
```
[root@fss7310_02 ~]# vxdisk rm emc0_2273
[root@fss7310_01 ~]# vxdisk rm emc0_2273
```
Note:
If you encounter an error, wait for a few minutes and run the command again.
Run the settag command to apply the tags to the underlying disk:
```
# vxdisk settag emc0_2305 tag=pool1
```

Run the vxdiskadm command and choose option #5 to replace the failed disk.

[root@fss7310_01 ~]# vxdiskadm

Volume Manager Support Operations
Menu:: VolumeManager/Disk

1 Add or initialize one or more disks
2 Encapsulate one or more disks
3 Remove a disk
4 Remove a disk for replacement 5 Replace a failed or removed disk
6 Mirror volumes on a disk
7 Move volumes from a disk
8 Enable access to (import) a disk group
9 Remove access to (deport) a disk group
10 Enable (online) a disk device
11 Disable (offline) a disk device
12 Mark a disk as a spare for a disk group
13 Turn off the spare flag on a disk
14 Unrelocate subdisks back to a disk
15 Exclude a disk from hot-relocation use
16 Make a disk available for hot-relocation use
17 Prevent multipathing/Suppress devices from VxVM's view
18 Allow multipathing/Unsuppress devices from VxVM's view
19 List currently suppressed/non-multipathed devices
20 Change the disk naming scheme
21 Change/Display the default disk layouts
22 Dynamic Reconfiguration Operations
list List disk information

? Display help about menu
?? Display help about the menuing system
q Exit from menus

Select an operation to perform: 5
Replace a failed or removed disk

Menu:: VolumeManager/Disk/ReplaceDisk
Use this menu operation to specify a replacement disk for a disk
that you removed with the "Remove a disk for replacement" menu
operation, or that failed during use. You will be prompted for
a disk name to replace and a disk device to use as a replacement.
You can choose an uninitialized disk, in which case the disk will
be initialized, or you can choose a disk that you have already
initialized using the Add or initialize a disk menu operation.
Select a removed or failed disk [<disk>,list,q,?] list
Disk group: sfsdg

DM NAME      DEVICE TYPE PRIVLEN PUBLEN STATE
dm emc0_2273 -      -    -       -      NODEVICE

Select a removed or failed disk [<disk>,list,q,?] emc0_2273
The following devices are available as replacements:
emc0_2305
You can choose one of these devices to replace emc0_2255. Choose 
"none" to initialize another device to replace emc0_2255.
Choose a device, or select "none" [<device>,none,q,?] 
(default: emc0_2305) emc0_2305
VxVM INFO V-5-2-382
The requested operation is to use the initialized device emc0_2305
to replace the removed or failed disk emc0_2273 in disk group sfsdg.

Continue with operation? [y,n,q,?] (default: y)
Use FMR for plex resync? [y,n,q,?] (default: n) VxVM vxrecover 
ERROR V-5-1-16084 Disk group: sfsdg is shared. The command can be 
executed only on the CVM master. Use -c option to recover all the shared 
disk groups from slaves.
VxVM INFO V-5-2-282 Replacement of disk emc0_2273 in group sfsdg 
with disk device emc0_2305 completed successfully.
Replace another disk? [y,n,q,?] (default: n)

Run the following command to trigger a recovery for the affected volumes.
```
# vxrecover -b -c -s vol1
```

Rename the disk to the disk access name to avoid the vxdg issue.

# vxedit -g sfsdg rename emc0_2273 emc0_2305

# vxdisk list | grep emc0_2305
emc0_2305 auto:cdsdisk emc0_2305 sfsdg online shared

Rename the subdisks as per the naming convention that is followed for the newly added disk.

# vxedit -g sfsdg rename emc0_2273-02 emc0_2305-02
# vxedit -g sfsdg rename emc0_2273-03 emc0_2305-03

# vxprint -pvs | grep -i emc0_2305
sd emc0_2305-02 vol1-P02 ENABLED 699136 0 - - -
sd emc0_2305-03 vol1_dcl-02 ENABLED 67840 0 - - -
# vxprint -pvs | grep -i emc0_2273