I want to add a new harddisk to an existing VM and want the best performance possible. The new hard disk will exist on an NFS datastore. Currently I did the following:
Is there a better way to do this? Should I be doing some vmware-ish file system instead?
With VMFS5 no longer having the 2TB limit for a VMFS volume, I'm considering which scenario would be more beneficial overall:-
In my case, I have a new 24-disk storage array with 600GB disks. I'll be using RAID10, so roughly 7.2TB, and trying to decide whether to go with 1 big 7TB datastore, or multiple stores of 1TB each.
What are the pros and cons of each approach?
Update: Of course, I neglected to include hot spares in my calculation, so it'll be just under 7.2TB, but the general idea is the same. :-)
Update 2: There are 60 VMs and 3 hosts. None of our VMs are particularly I/O intensive. Most of them are web/app servers, and also things like monitoring (munin/nagios), 2 Windows DCs with minimal load, and so on. DB servers are rarely virtualised unless they have VERY low I/O requirements. Right now I think the only virtual DB server we have is an MSSQL box and the DB on that box is <1GB.
Update 3: Some more info on the array and FC connectivity. The array is an IBM DS3524, 2 controllers with 2GB cache each. 4x 8Gbit FC ports per controller. Each ESXi host has 2x 4Gbit FC HBAs.
I have a ESXi servers (4.1 U1) connected to an iSCSI NAS, where 4 LUNS have been defined and presented to this host; all the LUNs are 3 TB in size. ESXi correctly sees the LUNs and acknowledges their 3 TB size.
I know the maximum size for a VMFS datastore is 2 TB, so creating a single datastore for each LUN would be a waste of space; I also know that creating multiple datastores on a single LUN is not a best practice, and it doesn't seem to work either: if there already is a datastore on a LUN, the vSphere Client just doesn't let me create anything else there, it doesn't even list it in the list of available devices for creating datastores.
I know I can use extents to create a datastore bigger than 2 TB, but this only seems to work across multiple LUNs: when I try to increase the size of a datastore using the same LUN where it resides, ESXi tries to actually increase it, so it won't go above 2 TB in size.
My question is: is there any way to combine two extents in the same LUN, so effectively creating a 3 TB datastore made up by 2 1.5 TB extents?
If this is not possible, is it possible to create two datastores in the same iSCSI LUN? I know it's not best practice, but it should at least be possilbe... but looks like it isn't.
If even this is not possible, then... how to make use of these 3 TB LUNs?
AFAIK VMWare utilise it's own filesystem vmfs for performance and efficiency reasons.
What will that be if I host my VMs on an Openfiler server which setup as NAS using ext3 filesystem?
Thanks
I've been experiencing this issue for a couple of months now where my ESX hosts lose connectivity with my iSCSI SAN vmfs volumes.
As a results the ESX hosts enter a nonresponsive mode the associated VMs disconnect and the only remedy is to reboot the host.
This issue happens randomly . I have escalated this issue with VMWare but I haven't had any solution to the issue yet.
I see no errors on my switches and there are no hardware issues as well. My SAN infrastucture is solid and there are 2 paths for every vmfs volume.
Did anybody else experienced a similar issue?
edit: Here are some more details:
The iSCSI SAN software is Datacore Sanmelody 2.0.4.2 running on 2 HP Proliant G5 servers. The storage attached to each of the servers is an HP MSA70 and all the iSCSI SAN Volumes that are presented to my 4 ESX hosts are mirrored.
I have two iSCSI swithces HP Procurve 1800G-24 that are trunked together. My SANLELODY servers are using NC360T NICs. I team two NICs and have one cable connecting to each iSCSi switch. Each ESX server uses two NICs as well for the iSCSI Network.