[itdiscuss] ESX and iSCSI

[Dan Barber]

I mean, unless you have a virtual server like SQL or Exchange pulling heavy loads, there is no need for RDM. The two purposes for which RDM was created are:

*         Maximize performance for heavy loads by eliminating VMFS overhead.

*         Allow for physical-to-virtual clustering or standby sparing, where the physical machine cannot read a VMFS partition.

Unless you have one of those scenarios (only you can truly judge a "heavy" load), then it seems unnecessarily complicated. We have a 30GB Exchange DB on a SATA VMFS volume with no performance issues and about 125 users (50-75 concurrent at any one time).

Dan

From: discuss-bounces at itdiscuss.org [mailto:discuss-bounces at itdiscuss.org] On Behalf Of blloyd at buskercom.com
Sent: Wednesday, August 13, 2008 11:30 AM
To: discuss at itdiscuss.org
Subject: Re: [itdiscuss] ESX and iSCSI

What do you mean "lighter loads"?



Bill Lloyd
IT Manager
[cid:image001.jpg at 01C8FD4C.2FDFD840]

5375 Oakbrook Parkway
Norcross, GA 30093
Phone: 770-417-1604
Cell:     404-379-6963

blloyd at buskercom.com
This email and any accompanying attachments may contain confidential and proprietary information. If you are not the intended recipient, you are requested to delete this entire communication immediately. Emails cannot be guaranteed to be secure or free of errors or viruses. The sender does not accept any liability or responsibility for any problems that may result from emails you receive.
From: discuss-bounces at itdiscuss.org [mailto:discuss-bounces at itdiscuss.org] On Behalf Of Dan Barber
Sent: Wednesday, August 13, 2008 11:50 AM
To: 'IT Discussion Forum'
Subject: Re: [itdiscuss] ESX and iSCSI

I don't use CHAP, but just use a separate VLAN, and secure that VLAN so that there is no access to it, physical or otherwise, without the appropriate measures. That way the storage is safe.

We don't use RDM, simply because there seems to be no need for lighter loads. Unless you are hitting a very high-speed or very large database, you should be okay.

Dan

From: discuss-bounces at itdiscuss.org [mailto:discuss-bounces at itdiscuss.org] On Behalf Of blloyd at buskercom.com
Sent: Wednesday, August 13, 2008 8:10 AM
To: discuss at itdiscuss.org
Subject: [itdiscuss] ESX and iSCSI

I have an opinion question to ask those of you who are using ESX with an iSCSI SAN.  Do you think it is better to use raw disk mapping for your VMs or VMFS partitions?  I am starting fresh with a new ESX server and trying to start right.

Another question for you is about CHAP authentication.  I am able to get my ESX system to connect as long as I don't use CHAP.  Anyone have thoughts about why this might be the case?

Thanks,



Bill Lloyd
IT Manager
[cid:image001.jpg at 01C8FD4C.2FDFD840]

5375 Oakbrook Parkway
Norcross, GA 30093
Phone: 770-417-1604
Cell:     404-379-6963

blloyd at buskercom.com
This email and any accompanying attachments may contain confidential and proprietary information. If you are not the intended recipient, you are requested to delete this entire communication immediately. Emails cannot be guaranteed to be secure or free of errors or viruses. The sender does not accept any liability or responsibility for any problems that may result from emails you receive.
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