When troubleshooting a NetScaler appliance we should know the hard disk partition that is mounted on the /var directory. It differs according to the NetScaler appliance model.

To check free space:
root@netscaler# df –h
Filesystem Size Used Avail Capacity Mounted on
/dev/md0c 161M 156M 2.6M 98% /
/dev/ad0s1a 237M 133M 85M 61% /flash
/dev/da0s1e 23G 8.7G 13G 41% /var
procfs 4.0K 4.0K 0B 100% /proc

To verify the mount point on the /var directory:
root@netscaler# mount
/dev/md0c on / (ufs, local)
/dev/ad0s1a on /flash (ufs, local)
/dev/da0s1e on /var (ufs, local)
procfs on /proc (procfs, local)

The hard disk names for the various Citrix NetScaler appliance models:

The following models use the /dev/ad2s1e device name for the hard disk:
-7000
-9010
-10010
-12000 series

The following models use the /dev/ad4s1e device name for the hard disk:
-MPX-15000
-MPX-17000
-MPX-8200
-MPX-5650
-MPX-8015
-MPX-8005

The following models use the /dev/ad6s1e device name for the hard disk:
-MPX-5500***
-MPX-7500***
-MPX-9500***
-MPX-9700
-MPX-10500
-MPX-12500
-MPX-15500

These models may also use the /dev/ad0s1e device name for the hard disk, please check article CTX121853.

The following models use the /dev/ad8s1e device name for the hard disk:
-MPX-11500
-MPX-17550

The following model uses the /dev/da0s1e device name for the hard disk:
-9950

To mount a /flash drive on a NetScaler, we need a serial connection to the NetScaler appliance with the following specifications:

9600 bits per second
8 data bits
No parity
1 stop bit

To mount the missing flash drive, complete the following procedure:

1.Connect a console cable to the NetScaler appliance Serial Console.
2.Restart the NetScaler appliance.
3.Press the SPACEBAR key as soon as the following message is displayed:

Hit [Enter] to boot immediately, or any other key for command prompt
Booting [kernel] in 10 seconds

Note: On the NetScaler 7000 appliance, press the Ctrl+C keys simultaneously.

4.To start the kernel of the appliance in the single user mode, run the following command:
boot -s

5.Press the Enter key as soon as the following message is displayed:
Enter full pathname of shell or RETURN for /bin/sh:

Note: The prompt of the appliance changes to \u@\h\$.

6.Run the following command to verify the disk consistency:
\u@\h\$ /sbin/fsck <Device_Name>

7.Run the following command to verify if the flash drive is mounted:
\u@\h\$ df –k

8.If the output of the preceding command does not display the flash drive, then run the following command to mount the flash drive:
\u@\h\$ /sbin/mount <Device_Name> /flash

Note: For NetScaler 10.5, use -t ufs command with fsck and mount command.

9.Restart the NetScaler appliance.

10.From the shell prompt, run the following command to verify if the flash drive is mounted:
root # df –k