- Community Home
- >
- Storage
- >
- Entry Storage Systems
- >
- Disk Enclosures
- >
- Write latency
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
тАО08-21-2009 06:17 AM
тАО08-21-2009 06:17 AM
What does us mean? microsecond?
i collected an average write latency (the physical diskgroup) of 14000 with a lot of peaks up to 60.000. Is this too high (i think this is 60 ms)? What causes a high write latency?
Solved! Go to Solution.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО08-24-2009 02:07 AM
тАО08-24-2009 02:07 AM
SolutionCheck here: http://h71028.www7.hp.com/ERC/downloads/5983-1674EN.pdf
page 12
You should have latencies of a few dozens of ms, not several thousands.
What's the drive queue depth?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО08-24-2009 02:28 AM
тАО08-24-2009 02:28 AM
Re: Write latency
If i take a look to the VDISK latencies then it looks normal (write latency < 2ms).
But the latency on the phisycal disk group has an average of 13ms with peaks up to 60ms. Is this the sum of all write latencies from the vdisks? Is this normal?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО08-24-2009 03:20 AM
тАО08-24-2009 03:20 AM
Re: Write latency
An I/O operation is considered done once the data is in the cache, no need to wait for the disks. So usually the write latency is 1 - 5 ms. Of course the time it takes to really write that data to the disks is higher, but that's not perceived from the outside.
Unless you have a disk with incredible high latencies (several hundred ms), the numbers you're seeing are normal.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО08-24-2009 03:26 AM
тАО08-24-2009 03:26 AM