- Community Home
- >
- Storage
- >
- Entry Storage Systems
- >
- Disk Enclosures
- >
- Re: Read / write latency - EVA6400
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО12-27-2010 12:04 AM
тАО12-27-2010 12:04 AM
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО12-27-2010 09:21 PM
тАО12-27-2010 09:21 PM
SolutionIt also matters where you are seeing the latencies?
If seeing from the EVAPerf, you will get different values for physical disk and diskgroup. For the sake of discussion I will keep the physical disks out of perfromance discussions because write cache on HSV controllers and read-ahead (cache hit) will play a major role in performance enhancement.
From the DiskGroup view, 15-20ms should be reasonable but depending upon applications (like fileshares, backups) 30ms will be acceptable.
A major factor in reading performance logs is collection interval, if collecting at very high interval (e.g. 60 seconds) a lot of peaks will be averaged out and will make performance study difficult.
Hope that helps.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО12-28-2010 12:08 AM
тАО12-28-2010 12:08 AM
Re: Read / write latency - EVA6400
-inex
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО12-28-2010 12:38 AM
тАО12-28-2010 12:38 AM
Re: Read / write latency - EVA6400
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c01685240
The commonly used values are:
Read latency
< 15 ms for FC disks
< 25 ms for FATA disks
Write latency
< 5 ms
Also read these:
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c01846577
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c01671044
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО12-30-2010 09:09 AM
тАО12-30-2010 09:09 AM
Re: Read / write latency - EVA6400
-inex
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-01-2011 08:14 PM
тАО01-01-2011 08:14 PM
Re: Read / write latency - EVA6400
In the mentioned sync/async scenario I couldn't figure out where were you measuring the latencies? Was it on LUN being synchronized or all the LUNs?
High latencies on synchronous replication is normal because it will include the delay to transmit the data to remote array and acknowledgement from the remote array. If the link between two arrays is not very fast it's highly recommended to use asynchronous replication.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-02-2011 04:48 AM
тАО01-02-2011 04:48 AM
Re: Read / write latency - EVA6400
-inex