- Community Home
- >
- Storage
- >
- Entry Storage Systems
- >
- Disk Enclosures
- >
- XP256 & Sybase use of raw device files
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
тАО04-02-2001 11:37 AM
тАО04-02-2001 11:37 AM
XP256 & Sybase use of raw device files
We have two N4000s and a K580 hooked up to a XP256 via fibre channel through two Brocade FC switches (for redundancy), not in a MC/SG environment.
Whenever one of the channels on the XP256 goes down, everything (OS, Oracle, etc.) fails over, but Sybase has problems.
The only thing we've been able to think of is that Sybase is having problems because it is using the raw device files, not an acutal filesystem.
Can anyone shed some light on this problem? Why would Sybase have problems, while every other application can handle it?
We've asked Sybase, and they haven't come back with an answer yet.
Thanks,
Jeff Norek
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО04-03-2001 10:52 AM
тАО04-03-2001 10:52 AM
Re: XP256 & Sybase use of raw device files
It might be that you're using asynchronous access to the raw device files. This is controlled by the devicefile /dev/async, the minor number controls the handling of time-outs.
If you use a minornumber 4, like this:
/dev/async 101 0x000004, disk-timeouts will be reported to Sybase and this will trigger sybase to locate the Sybase mirror database. If you do not have a Sybase mirror database it will most likely corrupt your database.
Here are the options for the minornumbers:
0x000000 default
0x000001 enable immediate reporting
0x000002 flush the CPU cache after reads
0x000004 allow disks to timeout
0x000005 is a combination of 1 and 4
0x000007 is a combination of 1, 2 and 4
Hope this helps,
Mark
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО06-15-2001 09:34 AM
тАО06-15-2001 09:34 AM
Re: XP256 & Sybase use of raw device files
Did you manage to find a fix for this sybase corruption problem.
We have the same problem on sybase with raw LVs on EMC connected via Brocade Fabric.
Thanks
ven
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО06-16-2001 08:08 AM
тАО06-16-2001 08:08 AM
Re: XP256 & Sybase use of raw device files
If you're using /dev/rdsk/c?t?d? files for raw access, you're not using PVLinks. You need to fail over to the backup path to the XP.
This can be resolved by creating volume group and LVs (don't forget the PVLinks), and accessing the LV in a raw manner (ie: /dev/sybase_vg/rlvol1).
Good luck
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО06-18-2001 05:04 AM
тАО06-18-2001 05:04 AM
Re: XP256 & Sybase use of raw device files
alternate PV link takes over after the primary path timeout (default 30 secs).
The problem is that sybase configured to use "async i/o" driver corrupts the DB while this pvlink switchover takes place.
One option is to decrease the timeout and force the alternate PV link to take over after a shorter timeout period. But it may trigger false switchover on heavy i/o load.
This is our production and i don't have the option to testing any solution.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО06-18-2001 08:44 AM
тАО06-18-2001 08:44 AM
Re: XP256 & Sybase use of raw device files
The problem you describe is probably the minor number of the async driver as I mentioned in my earlier response:
If you use a minornumber 4, like this:
/dev/async 101 0x000004, disk-timeouts will be reported to Sybase and this will trigger sybase to locate the Sybase mirror database. If you do not have a Sybase mirror database it will most likely corrupt your database.
Here are the options for the minornumbers:
0x000000 default
0x000001 enable immediate reporting
0x000002 flush the CPU cache after reads
0x000004 allow disks to timeout
0x000005 is a combination of 1 and 4
0x000007 is a combination of 1, 2 and 4
So ig you use 0x000000 Sybase does not know about the failing link and will wait untill lvm has switched to the alternate path.