Adding raw storage - iSCSI or VMDK?

Question

We have about 10TB of files that we use on our fileserver. I'll be setting up a new server with more space and better backups. We have a SAS box with 24 drives connected to OpenIndiana server configured as a pool of 11 mirrored drives with two spares. Is it better to present the pool of drives as a iscsi target to a Windows fileserver directly and store files that way or connect it to a exsi server and store the data within vmdk disks?

Answer 1

You can do both.

The zpool is just your top-level group of devices. You can carve that up into as many ZFS filesystems as you'd like. That includes zvols (volumes that can be exported as block devices).

A major point of using ZFS is to give you maximum storage flexibility.

For example, I have the following set of ZFS filesystems, where the first four listed are NFS mounts exported to a VMware vSphere 5.1 cluster... but the last export is an iSCSI export mounted directly by a virtual machine. It's all backed by the same storage, but you can do whatever is needed by your application or environment.

root@deore:/volumes# zfs list
vol1/Valley               298G   524G   209G  /volumes/vol1/Valley
vol1/dc1                 11.2G   524G  10.7G  /volumes/vol1/dc1
vol1/isos                4.49G   524G  4.49G  /volumes/vol1/isos
vol1/staging             76.7G   524G  76.7G  /volumes/vol1/staging
vol1/yum                  115G   524G   115G  -

In practice, I tend to use ZFS NFS filesystems for VMware and iSCSI for backup storage or where I need a particular native filesystem presented to an OS (e.g. NTFS).

Answer 2

If you give your file server its storage through VMFS, you will have more flexibility with VMWare. They allow hot VMotion with raw devices, however storage VMotion won't work.