- Community Home
- >
- Servers and Operating Systems
- >
- Operating Systems
- >
- Operating System - HP-UX
- >
- Low Buffer cache Hit Ratio's & I/O bottlenecks
Operating System - HP-UX
1753766
Members
5804
Online
108799
Solutions
Forums
Categories
Company
Local Language
back
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Discussions
back
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
Blogs
Information
Community
Resources
Community Language
Language
Forums
Blogs
Go to solution
Topic Options
- 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
05-24-2002 09:56 AM
05-24-2002 09:56 AM
Re: Low Buffer cache Hit Ratio's & I/O bottlenecks
A word of caution, the mincache and convosync mount options should be used ONLY for the database mount point ONLY. Using these options on other file systems can heavily degrade throughput.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-25-2002 11:46 AM
05-25-2002 11:46 AM
Re: Low Buffer cache Hit Ratio's & I/O bottlenecks
On the cooked V raw I have an opionion...
I'm an Informix guy and saw the comments about Informix using raw LVM and Oracle using cooked. The reasoning is really quite simple.
1 - Efficient use of memory - Dbase buffers keep most frequently/recent used pages there - HP-UX buffer cache is used to keep most recent pages there. If you have an OLTP DBase (NOT OLAP, or DSS as these tend to flush the buffers anyway), then using cooked filesystems means that the pages are in memory twice, one in the DBase buffers & one in buffer cache, very inefficient.
2 - There is a possiblity that the DBase could do a write & crash before the buffer cache has flused to disk
Given the above you would pick raw....
On the other hand....
1 - It is easier to defragment a cooked filesystem & therefore improve performance this way.
2 - Memory is cheap & plentiful.
3 - The performance of cooked filesystems can be better than raw (so I'm told).
4 - JFS should not allow any data loss
From the above you can see there are arguments either way and it tends to be that people take up what their vendors say.
On the % cache ratio, if you copied the raw LV's to raw LV's it should not pass through the buffercache at all....
That way my 0.02??? worth
Tim
I'm an Informix guy and saw the comments about Informix using raw LVM and Oracle using cooked. The reasoning is really quite simple.
1 - Efficient use of memory - Dbase buffers keep most frequently/recent used pages there - HP-UX buffer cache is used to keep most recent pages there. If you have an OLTP DBase (NOT OLAP, or DSS as these tend to flush the buffers anyway), then using cooked filesystems means that the pages are in memory twice, one in the DBase buffers & one in buffer cache, very inefficient.
2 - There is a possiblity that the DBase could do a write & crash before the buffer cache has flused to disk
Given the above you would pick raw....
On the other hand....
1 - It is easier to defragment a cooked filesystem & therefore improve performance this way.
2 - Memory is cheap & plentiful.
3 - The performance of cooked filesystems can be better than raw (so I'm told).
4 - JFS should not allow any data loss
From the above you can see there are arguments either way and it tends to be that people take up what their vendors say.
On the % cache ratio, if you copied the raw LV's to raw LV's it should not pass through the buffercache at all....
That way my 0.02??? worth
Tim
-
- « Previous
-
- 1
- 2
- Next »
The opinions expressed above are the personal opinions of the authors, not of Hewlett Packard Enterprise. By using this site, you accept the Terms of Use and Rules of Participation.
News and Events
Support
© Copyright 2024 Hewlett Packard Enterprise Development LP