Sybase NNTP forums - End Of Life (EOL)

The NNTP forums from Sybase - forums.sybase.com - are now closed.

All new questions should be directed to the appropriate forum at the SAP Community Network (SCN).

Individual products have links to the respective forums on SCN, or you can go to SCN and search for your product in the search box (upper right corner) to find your specific developer center.

Recover Tempdb when device fails

4 posts in General Discussion Last posting was on 2011-12-21 17:28:18.0Z
SteveS Posted on 2011-12-21 15:32:04.0Z
Sender: 1b0c.4ef1fa1f.1804289383@sybase.com
From: SteveS
Newsgroups: sybase.public.ase.general
Subject: Recover Tempdb when device fails
X-Mailer: WebNews to Mail Gateway v1.1t
Message-ID: <4ef1fbf4.1b9b.1681692777@sybase.com>
NNTP-Posting-Host: 172.20.134.41
X-Original-NNTP-Posting-Host: 172.20.134.41
Date: 21 Dec 2011 07:32:04 -0800
X-Trace: forums-1-dub 1324481524 172.20.134.41 (21 Dec 2011 07:32:04 -0800)
X-Original-Trace: 21 Dec 2011 07:32:04 -0800, 172.20.134.41
Lines: 9
Path: forums-1-dub!not-for-mail
Xref: forums-1-dub sybase.public.ase.general:30781
Article PK: 73671

I have tempdb allocated to an SSD device(no extents on
master). If the device failed how could I move tempdb to
other disk. My thoughts:
A: Sybase crashes. Can I get up to a point where I can make
changes?
B: Sybase doesn't crash. Can it be done on the fly? (drop
extents,edit system tables, etc.)

Any doc on this type of scenario?


SteveS Posted on 2011-12-21 16:49:32.0Z
Sender: 1c8a.4ef20093.1804289383@sybase.com
From: SteveS
Newsgroups: sybase.public.ase.general
Subject: Re: Recover Tempdb when device fails
X-Mailer: WebNews to Mail Gateway v1.1t
Message-ID: <4ef20e1c.1fa3.1681692777@sybase.com>
References: <4ef1fbf4.1b9b.1681692777@sybase.com>
NNTP-Posting-Host: 172.20.134.41
X-Original-NNTP-Posting-Host: 172.20.134.41
Date: 21 Dec 2011 08:49:32 -0800
X-Trace: forums-1-dub 1324486172 172.20.134.41 (21 Dec 2011 08:49:32 -0800)
X-Original-Trace: 21 Dec 2011 08:49:32 -0800, 172.20.134.41
Lines: 13
Path: forums-1-dub!not-for-mail
Xref: forums-1-dub sybase.public.ase.general:30782
Article PK: 73670


> I have tempdb allocated to an SSD device(no extents on
> master). If the device failed how could I move tempdb to
> other disk. My thoughts:
> A: Sybase crashes. Can I get up to a point where I can
> make changes?
> B: Sybase doesn't crash. Can it be done on the fly? (drop
> extents,edit system tables, etc.)
>
> Any doc on this type of scenario?

Since the SSD is a UNIX logical volume and tempdb is
recreated at startup, could I just recreate the logical
volume on a different device? Anything I'm not considering?


J Posted on 2011-12-21 17:28:18.0Z
From: jtotally_bogus@sbcglobal.net (J)
Newsgroups: sybase.public.ase.general
Subject: Re: Recover Tempdb when device fails
Reply-To: J@bogusemailAddress.com
Message-ID: <4ef216c7.1991831578@forums.sybase.com>
References: <4ef1fbf4.1b9b.1681692777@sybase.com> <4ef20e1c.1fa3.1681692777@sybase.com>
X-Newsreader: Forte Free Agent 1.21/32.243
NNTP-Posting-Host: vip152.sybase.com
X-Original-NNTP-Posting-Host: vip152.sybase.com
Date: 21 Dec 2011 09:28:18 -0800
X-Trace: forums-1-dub 1324488498 10.22.241.152 (21 Dec 2011 09:28:18 -0800)
X-Original-Trace: 21 Dec 2011 09:28:18 -0800, vip152.sybase.com
Lines: 24
Path: forums-1-dub!not-for-mail
Xref: forums-1-dub sybase.public.ase.general:30784
Article PK: 73674

On 21 Dec 2011 08:49:32 -0800, SteveS wrote:

Steven,

How about a symbolic link to the SSD file for tempdb? If you lose the
SSD and recycle ASE then first change the symbolic link to point to
your backup device-file.

Jay

>> I have tempdb allocated to an SSD device(no extents on
>> master). If the device failed how could I move tempdb to
>> other disk. My thoughts:
>> A: Sybase crashes. Can I get up to a point where I can
>> make changes?
>> B: Sybase doesn't crash. Can it be done on the fly? (drop
>> extents,edit system tables, etc.)
>>
>> Any doc on this type of scenario?
>
>Since the SSD is a UNIX logical volume and tempdb is
>recreated at startup, could I just recreate the logical
>volume on a different device? Anything I'm not considering?


"Mark A. Parsons" <iron_horse Posted on 2011-12-21 17:23:01.0Z
From: "Mark A. Parsons" <iron_horse@no_spamola.compuserve.com>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.13) Gecko/20101207 Lightning/1.0b2 Thunderbird/3.1.7
MIME-Version: 1.0
Newsgroups: sybase.public.ase.general
Subject: Re: Recover Tempdb when device fails
References: <4ef1fbf4.1b9b.1681692777@sybase.com>
In-Reply-To: <4ef1fbf4.1b9b.1681692777@sybase.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
NNTP-Posting-Host: vip152.sybase.com
X-Original-NNTP-Posting-Host: vip152.sybase.com
Message-ID: <4ef215f5@forums-1-dub>
Date: 21 Dec 2011 09:23:01 -0800
X-Trace: forums-1-dub 1324488181 10.22.241.152 (21 Dec 2011 09:23:01 -0800)
X-Original-Trace: 21 Dec 2011 09:23:01 -0800, vip152.sybase.com
Lines: 26
Path: forums-1-dub!not-for-mail
Xref: forums-1-dub sybase.public.ase.general:30783
Article PK: 73675

If you've removed the initial fragment from the master device you may have problems getting your dataserver to start up
if the non-master device(s) on which the tempdb database resides does not exist.

Life will be a bit easier if you leave the initial 2-4MB (or whatever) residing on the master device. (you can drop all
database segments from this disk fragment from within the tempdb database) If for some reason the device(s) upon which
tempdb resides are not available you should still be able to startup the dataserver (because the initial fragment exists
on the master device).

As for addressing the issue 'on the fly' ... with newer releases of ASE you may be able to do an on-the-fly rebuild of
the tempdb database by a) modifying sysusages and b) "running dbcc dbreboot ('reboot','tempdb')". (NOTE: While I've
used dbreboot many times I haven't tried it on tempdb, so best bet is to try it - preferably in a dev/test environment
- and see if it works.)

As for documentation ... see the Sys Admin Guides and/or Troubleshooting guide for disaster recovery steps (eg, what to
do if a device is lost).

On 12/21/2011 10:32, SteveS wrote:
> I have tempdb allocated to an SSD device(no extents on
> master). If the device failed how could I move tempdb to
> other disk. My thoughts:
> A: Sybase crashes. Can I get up to a point where I can make
> changes?
> B: Sybase doesn't crash. Can it be done on the fly? (drop
> extents,edit system tables, etc.)
>
> Any doc on this type of scenario?