You are not logged in or registered. Please login or register to use the full functionality of this Website SybaseTeam.Com...
Hello There, Guest! (LoginRegister) Remember Me? Current time: 04-26-2015, 06:40 AM
   Home  |  About Us  |  Sybase Training  |  Synergy  |  Consulting  |  Job Openings  |  Tech Videos  |  Rules and Disclaimer  |  Search
Post Reply 
Forum Tools
Database device on NFS disk
11-24-2011, 08:10 AM
Post: #1
Quote this message in a reply
Database device on NFS disk

Hi Gurudev,

I have a query related to Sybase and NFS device.

Suppose there are two Server HostA and HostB.

- OS SUSE Linux
- Sybase ASE is installed
- NFS Client is installed
- User database device folder is /dbdata/data_local and /dbdata/data_remote

- OS SUSE Linux
- NFS Server is installed
- NFS shared folder is /dbdata/data

1) Create Sybase user on both the server with same user id and group id
2) NTP Server should be configured to sync both server.
3)NFS Server is setup on HostB
4) NFS Client is setup on HostA
5) Mounted HostB folder /dbdata/data on HostA folder /dbdata/data_remote
6) Ownership of /dbdata/data of HostB and /dbdata/data_local is given same and chmod changed to 777
7) Now user database which consist of total 7 devices
- device1 for non partition tables
- device2 for log device
- device3 to device7 used for Partitioning tables

Can I place few device on HostA and few device on HostB?
Is Sybase15.5 ASE supports this feature?

Thanks and regards,

Find all posts by this user
11-25-2011, 07:13 AM
Post: #2
Quote this message in a reply
RE: Database device on NFS disk

This is what I think

They are not two seperate filesystem to place few devices/files on HostB and few on HostA.
If the filesystem is on HostB and is NFS shared to HostA, even if you create files/devices from HostA effectively they would get created on the filesystem on HostB.

It does not make any difference where(HostA or HostB) you create the files/devices from as ultimately they get created on the FS on HostB.

You may try testing this.


Find all posts by this user
11-28-2011, 03:21 AM
Post: #3
Quote this message in a reply
RE: Database device on NFS disk

    (11-24-2011 08:10 AM)ranjitsybaseteam Wrote:  I have a query related to Sybase and NFS device.


    Can I place few device on HostA and few device on HostB?

Sybase ASE is a stand-alone server. Why would you want some devices on the host (which Sybase is deployed on) and some devices on another host ???

Using NFS is fine for emergencies (eg. testing a Disaster Recovery scenario) or bcp operations, etc. but not for Sybase Devices. NFS and NAS runs across the network, so it is very slow. Sybase is supposed to have its Devices on local disk or SAN only (Raw Partitions, but if you have a baby o/s, then file system files).

So they answer is, yes you can, but it is not reasonable or technically logical, to actually want slow devices, and to deploy ASE across the network. Fine for emergencies and very temporary needs, but not otherwise.
    Quote:Is Sybase15.5 ASE supports this feature?
What "feature" exactly, do you mean ? I have never heard of anyone who wants their Sybase ASE to run slower (NFS), or wants that as a "feature".

1. All Sybase versions "support" NFS devices. All Sybase sees is the file system node. How the file system is deployed, is outside Sybase: it does not know if the file is SAN/NFS/NAS/Local Disk.

In this scenario, Host B is not a "Host"; it is just the location where "some" of your files are located, accessible via NFS from Host A, and Host A is all that counts. And if Host B goes down, the entire database on Host A will be unavailable and has to be recovered from dump files.

2. If you are talking about exporting an entire database to another Sybase ASE server, by moving its devices, as distinct from the DUMP/LOAD DATABASE method, then yes, we have had that since 12.5.4. That is one of the very temporary uses. Read up on the MOUNT and QUIESCE DATABASE commands.

Ashirvad to my Shishyas, Cheers to the others
Derek Asirvadem
Information Architect / Sr Sybase DBA
Selection of Useful Documents for the Sybase DBA
Visit this user's website Find all posts by this user
Post Reply 

Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  Database Maintenance - A Perfect Overview mvsramarao 0 2,004 02-11-2013 01:46 PM
Last Post: mvsramarao
  Starting a Database server vinayp83 1 2,266 10-01-2012 08:05 AM
Last Post: DerekAsirvadem
  SQL script to calculate sybase database size ,data free,data used,log free,log used sybaseteam 8 43,085 08-10-2012 03:33 AM
Last Post: amby_1986
  Load of database taking long time raograjiv 2 3,318 08-06-2012 07:33 AM
Last Post: sarosh
  Feasible seperation of two database moonsong2008 3 2,109 04-15-2012 04:07 PM
Last Post: DerekAsirvadem
  Loading of Database in Sybase ASE 15 is taking longer time on weekends. raograjiv 6 3,809 04-13-2012 01:36 AM
Last Post: DerekAsirvadem
  How to Calculate Memory Usage and Disk Space Usage? rjvk 2 6,767 01-10-2012 10:51 AM
Last Post: Ugur Naciterhan
  Need sql for reading through each database rbulley 2 2,481 11-28-2011 02:16 AM
Last Post: DerekAsirvadem
  Minimum Master device and Master database size Joshi 2 4,029 10-05-2011 08:19 PM
Last Post: DerekAsirvadem
  How to Create new Database in ASE 15 jadeite100 2 4,483 10-04-2011 09:21 PM
Last Post: DerekAsirvadem

Forum Jump:

Contact Us | SybaseTeam | Disclaimer & Rules | Return to Top | Return to Content | Lite (Archive) Mode | RSS Syndication