VMware

This Question is Answered

1 "correct" answer available (10 pts) 2 "helpful" answers available (6 pts)
1 2 3 Previous Next 32 Replies Last post: Sep 2, 2009 10:25 PM by grantdavies  

ESXi 3.5 U4 on HP DL380 G6 has slow disk performance posted: May 6, 2009 2:45 PM

Click to view Keith001's profile Novice 7 posts since
May 6, 2009

I've installed ESXi 3.5 U4 with and without the latest VMware patches on an HP DL380 G6 server with a p410i RAID controller configured with 8 SAS drives in a RAID 50 configuration. The server firmware (RAID controller and BIOS) have been updated to the most current versions.

Unfortunately, a RHEL4 VM only achieves a maximum of 5-6 MB/s in disk IO for write operations. When I run 2 different RHEL4 VM's simultaneously, the disk write performance is 2.5-3 MB/s each.

I'm fairly certain the HW is good because I've performed a native installation of RHEL5U3 on the server and have used that OS to do a local file copy at 250+ MB/s.

Does anyone have any knowledge of performance issues regarding the HP Smart Array p410i RAID controller and the VMware ESXi 3.5 U4 cciss driver?


Click to view Jackobli's profile Master 1,100 posts since
Aug 28, 2007
Hello and welcome to the VMware ESXi community forum.

Which kind of the p410 do you own? Regular setup or the extended with a battery backed write cache?
Of first, most probably the smart array adapater is not using a write cache (100% of RAM for read, 0% for write).
As ESXi itself does not cache writes, a bad write performance is obvious.
Click to view Jackobli's profile Master 1,100 posts since
Aug 28, 2007
Keith001 schrieb:
I have a hard time believeing that my RAID write IO is so slow when compared to RHEL4U3 installed natively.
Did you read my words? ESXi does not cache itself. So any write goes directly to the disk (except, if you install a BBWC).
Any given linux is using it's RAM quite excessive for caching IO, so you really cannot compare.
Click to view fossmarkluni's profile Lurker 2 posts since
May 13, 2009

Same here.. HP ML 370 G6 w/ 2 x E5520 and 12 gb RAM, P410i 256 mb without BBWC ESXi 3.5 U4.

2-3 MB/s write rate, which is unbelivable! Even without BBWC...

We have a HP XW4600 workstation w/ 1 x 500gb SATA for test purposes ESXi 3.5 U3, it easily writes 20 MB/s ++ with ACHI disabled (IDE mode)

BBWC battery kit ordered!

:S

Click to view Anton V Zhbankov's profile Champion 2,882 posts since
May 26, 2008
Do VMs show such speed all the time? By default VMDKs are created in "thick" mode, and on first access to block ESX wipes it out, causing low IOPS.
So if you run any disk test, do not take first result. Wait it to finish and run again.

Other way to prewipe all blocks is to create eagerzeroedthick VMDKs using vmkfstools command.

---
VMware vExpert '2009
http://blog.vadmin.ru
Click to view fossmarkluni's profile Lurker 2 posts since
May 13, 2009

Disk write can peak up to about 10 MB/s, but after a few secs goes down to 2-3 MB/s, have just one VM on this server ATM. (2008 server std 64 bit)

What I feel is so strange is that a normal (E8500, single SATA) workstation performs much better (disk write) than this brand new ML 370 G6, even without BBWC I expected the ML 370 to perform better!!


Click to view depping's profile Champion 2,997 posts since
Jan 17, 2005
Just download the RCLI or VIMA. vmkfstools is included in those.

Duncan
VMware Communities User Moderator | VCP | VCDX


Blogging: http://www.yellow-bricks.com
Twitter: http://www.twitter.com/depping

If you find this information useful, please award points for "correct" or "helpful".
Click to view PeteLong's profile Lurker 5 posts since
Apr 16, 2008

I Have the Same Problem

ML350 G6 410i RAID Card - ESX 3.5 update4

Call Logged to VMWare

Call Logged to HP - who are not being terribly helpfull - they have asked we run Array Diagnostic Utility from Smartstart.

Click to view grantdavies's profile Novice 6 posts since
Jan 26, 2009

We are running into this problem with one of our clients at the moment, can I ask - once you installed the BBWC and it was fully charged did the write performance improve without further adminisatrative intervention ordid you have to change some settings after the 2-3 days charging? Obviously we're going to upgrade them to BBWC and I'm just wondering whether we'll need to schedule a second maintenance window to configure the write caching on the controller once the battery charges.
Click to view PeteLong's profile Lurker 5 posts since
Apr 16, 2008

Added 512 Cache - did NOT fix the problem - HP said the Diagnostic Utility showed every drive had an error in the same sector - and that this was unlikely.

They asked that we firmware the RAID controler - it had a newer version than the current firmware CD (it was runing 1.62) Ive downgraded it to 1.58C

Just brought the server up this morning lets see how it performs..............

Click to view J1mbo's profile Expert 575 posts since
May 20, 2009
> we confirmed that our 8 disk RAID 50 volume was able to write at 70 MB/s (at least as long as the RAID cache didn't get saturated)


Is this sequential performance? I ask since it still seems quite low, the P400's should be able to achive over 150MB/s write according to this: http://cnscenter.future.co.kr/resource/rsc-center2/Tolly/Tolly206162Intel-IOP333SASRAID.pdf

I wonder if there is a partition alignment issue? (http://www.vmware.com/pdf/esx3_partition_align.pdf)

I read on here a while ago that automatically created VMFS partitions are not properly aligned and should be deleted and re-created using the VI Client - can't find it now predictably.

VMware Developer

SDKs, APIs, Videos, Learn and much more in the Developer community.

Learn More

Developer Sample Code

Increase your developer productivity with VMware API sample code.

Learn More

VMworld Sessions & Labs

Online access to the latest VMworld Sessions & Labs and online services.

Learn more

Purchase PSO Credits Online

Purchase credits to redeem training and consulting services online.

Buy Now

Community Hardware Software

View reported configurations or report your own.

Learn More

VMware vSphere

Come witness the next giant leap in virtualization.

Register Today

Communities