Iomega VMware ESX NFS Datastore Issue

In my VMware vSphere home lab I have been using for shared storage various hardware or software appliances: from Openfiler, Falconstor VSA, HP LeftHand/StorageWorks P4000 VSA to EMC Celerra VSA. Recently I have added Iomega ix4-200d. Its NFS sharing is VMware vSphere certified. Although Iomega is not very powerfull (see my previous blog post about Iomega) I moved all my VMs to it to free up my storage server to play with other storage appliances (I am testing Nexenta now, but that is for another blog post).

My setup is now very simple. I have diskless ESXi that runs all the VMs from the NFS datastore served by Iomega. Today I have restarted the ESXi server and was surprised that due to inaccessible NFS datastore no VM was started.  The datastore was grayed out in the vSphere Client GUI.

I have virtual domain controller, internet firewall/router, mail server and some other less important machines. So if the ESX does not start properly I have no internet, email and I cannot even log in to Iomega CIFS shares because it is joined to domain which was also not available.
I was very surprised as I had no idea why the ESX server could not connect to the NFS datastore. Storege rescan did not help, so I have unmounted the datastore and tried to reconnect it. I received this error message:

Call “HostDatastoreSystem.CreateNasDatastore” for object “ha-datastoresystem” on ESXi “10.0.4.202” failed.
Operation failed, diagnostics report: Unable to complete Sysinfo operation. Please see the VMkernel log file for more details.

VMkernel log (which is on ESXi stored in /var/log/messages) did not help much:

Jan 15 22:10:25 vmkernel: 0:00:01:30.282 cpu0:4767)WARNING: NFS: 946: MOUNT RPC failed with RPC status 13 (RPC was aborted due to timeout) trying to mount Server (10.0.4.251) Path (/nfs/Iomega)

I was able to connect to the NFS Iomega export from regular linux machine. I was also able to connect the ESX server to regular linux NFS export. And that helped me to find the solution.

Because both of my DNS servers were running in virtual machines and not accessible, Iomega took more time to connect the ESX server to the NFS datastore and ESX server meanwhile gave up. The remedy was very simple. To Iomega /etc/hosts file I have added a line with the ESX server IP address and its hostname. This must be done via Iomega ssh console and not via web GUI:

root@Iomega:/# cat /etc/hosts
127.0.0.1 localhost.localdomain localhost
10.0.4.251 Iomega.FOJTA.COM Iomega
10.0.2.251 Iomega.FOJTA.COM Iomega
10.0.4.202 esx2.fojta.com esx2

From now when the ESX server reboots it mounts the NFS datastore immediately.

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Iomega ix4-200d: The Good, The Bad and The Ugly

Recently I have added to my home lab NAS Iomega ix4-200d – with 4×2 TB hard drives. Here are some of my thoughts about the product.

Iomega makes consumer disk based products but since April 2010 is part of EMC. They are now claiming to deliver enterprise storage solutions to small and medium businesses. The Iomega’s biggest unit – 12 disk ix12-300r is rack mountable, with dual hot-swappable power supplies but with the same OS as my Iomega ix4 – EMC Lifeline Linux. I have read many blogs saying that Iomega is very good fit for VMware home labs. It is even on VMware hardware compatibility list.

So what are my thoughts?

The good

  • it is very small, neat and quiet unit with four 2 TB hard drives, if RAID5 is used you get around 5.5 TB of capacity
  • it is very simple to setup and use via web based GUI
  • it has many features: RAID 0/1/5, CIFS, NFS, iSCSI, FTP, TFTP, rsync and CIFS replication, Active Directory integration, Quotas, Printer server, USB ports for external drives, Bluetooth dongle or UPS communication, scheduled backups, power management, torrent client, …
  • dual ethernet ports, jumbo frames
  • as mentioned it is on VMware HCL
  • in this white paper EMC recommends the use of Iomega for Remote Office Branch Office (ROBO) deployments with centralized backup repository to Celerra

The Bad

  • it uses software RAID (linux mdadm), slow 5.9K rpm Seagate 2TB drives, ARM9 (ARM926EJ-S) CPU with 512 MB RAM, therefore the disk performance is not very good
  • the web based GUI is sometimes too simple and limiting
  • although it has many features, most of them are implemented on very basic level
  • the dual network ports do not support VLANs, using each port for different network segment is possible, but the separation of services is not done very well. For example you cannot limit the management interface to only one network.
  • only NFS is VMware certified, iSCSI is not. You cannot limit iSCSI to one network segment and separate LAN from SAN.

The Ugly

  • Very basic documentation
  • My hopes were that because of the Active Directory integration it could be used as replacement of Windows File server. Well, this is not the case. You can create shares with AD access control list only at the root level and only via the GUI. You cannot create subfolders with different access rights neither from Windows nor from the GUI. This makes it unusable for business deployment.

The result

I think the unit is perfect for home use. It has enough capacity to be used for home media – movies, music and photos, for backups and for some light VMware home lab usage. However for small businesses I would recommend to use it only for backups. I was expecting Iomega to have Celerra like features and am little bit dissapointed but that is probably too much to ask in this price range.