Thanks for all the advice - thanks to Romeo Theriaults awesome tool I'll run some stats over time and see how things look.
I'll probably give Logicmonitor a quick look and see how it compares to DFM.
Cheers, Raj.
On 10/7/09, Kevin M. Parker kevin@theparkerz.com wrote:
Raj, I'll share knowledge I've received specific to NFS environments (and this may be specific to VMware over NFS - sorry I can't confirm). The way I understand it is that clients start experiencing negative performance after 20ms disk latency. I do not know if that same latency applies to iSCSI traffic.
As it relates to the disks making up your aggregates, I can offer the following numbers as they relate to disk IOPS, which is also somewhat related to the original request in this thread. Numbers below are the IOPS that disk can sustain before experiencing a >= 20ms delay. FC@10KRPM: 120IOPS FC@15KRPM: 220IOPS SATA: 40IOPS
I had looked on NOW for this type info but did not come up w/anything quickly - perhaps you could reach out to your SE.
-/- Kevin Parker 919.521.8413 http://theparkerz.com Blackle.com - Saving energy one search at a time.
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Raj Patel Sent: Monday, October 05, 2009 12:59 AM To: Romeo Theriault Cc: Maxwell Reid; vera.lee@avagotech.com; Milazzo Giacomo; toasters@mathworks.com Subject: Re: High CPU utilizations and file I/O
As a matter of interest how much latency is to much (I know, how many angels can you fit on a pinhead) ?
We've had a few DBA types come and comment on long SQL queue lengths associated with disk i/o - the SQL luns are connected via iSCSI.
As far as the end user is concerned performance seems fine for things like SharePoint and CRM. Even Exchange. However a few apps with high i/o (mail archiving to database and SCOM which seems to thrash the database) do seem to suffer a little in terms of slow response time.
Do people have tips for optimising iSCSI performance (targets are ESX servers, Exchange on physical hardware and SQL on a mix of physical and virtual servers) ?
What key counters should I keep an eye on ?
Fibre Channel is still prohibitively expensive plus 10GbE seems very promising and more pervasive than a few years ago.
Cheers, Raj.
On 10/3/09, Romeo Theriault romeotheriault@gmail.com wrote:
I think everyone would be interested in the updated version!
Great! Ok, I'll put up the version that can also filter on aggregates
on
Monday. I hadn't put it up earlier mainly because it takes a bit more
setup
to get working. I used the netapp perl api to access the aggregate information so it also requires a user account with the appropriate
api
permissions and the associated netapp perl api modules. I just haven't gotten around to figuring out if I can legally bundle the netapp perl modules and just generally putting it in a easily usable package for
the
general public. I'll try to figure out the details on monday and see
what I
can get out, with or without the netapp modules.
-- Romeo Theriault System Administrator Information Technology Services
-
Raj Patel