Re: Discussion: Is a server with truncated logs safe?

I've just looked at your email... ER of course is a situation where the system exchanges information with others... This may be an issue, or eventually a good way to recover some information... You will know better the impact of it... Regards. On Thu, May 5, 2011 at 12:28 PM, Fernando Nunes <domusonline@gmail.com>wrote: > This is my personal opinion. Not my professional opinion nor my employer > view. > If the logs were "truncated" you should have the database in a perfectly > consistent state, but "in the past". > You will have problems if your system communicate with others, they may > have received information from it that currently it doesn't have. Or that > the other systems assume they have sent information to yours that it > currently does not recognize. > Also some users may find strange things, like having invoices printed that > are not stored on the system etc. > > Note that an export/import of the system will not solve any of the above... > > Ideally you should at least run complete onchecks... but these also take > time and may cause outage. > > What you should also proceed is to find the root cause (if possible). If > it's caused by a bug, you should upgrade ASAP. If the root cause was the > server crash (and this caused corruption) than the recommendation would > certainly be to export/import. > > Finally, there is a difference between "truncate the logs" and "tweak the > logs". Technical support can truncate the whole logical log, leaving your > system in a certain point in time, or eliminate some LL records that are > causing problems. What was done may influence the decision to export/import > > Regards. > > > > On Thu, May 5, 2011 at 12:08 PM, Jarrod Teale <Jarrod.Teale@fonterra.com>wrote: > >> So today we had the mother of all nasty scenarios. >> >> The server crashed and when restarting said “Cannot roll forward from >> checkpoint, contact IBM support”. >> >> Logical logs were in a mess. Not good. So IBM dial in and truncate the >> logs and sort the system out so it starts – yeah for onlog J >> >> They recommend not using the database anymore, but unloading everything >> and moving it to a new instance to ensure consistency. >> >> >> >> I buy the argument completely and it is the right thing to do. >> >> >> >> But... The issue I have is this – we can’t really afford the downtime >> until the milk season winds down for winter in a month or two. >> >> So... my question. >> >> What is the consensus about running on a database that has been log >> truncated? >> >> >> >> I want opinion on how urgent the full server rebuild is. >> >> If we have to do it today, then we need to try to find a way to do it with >> as little downtime as possible because the plant will still be running. This >> will be VERY complicated and basically the definition of annoying. >> >> >> >> On your marks, get set, discuss... >> >> >> >> Thanks >> >> >> >> Jarrod Teale >> >> [image: Fonterra 70px wide] >> >> Process Information Manager >> >> Automation and Process Control >> >> jarrod.teale@fonterra.com >> direct +64 7 850 7525 (ext 77525), mobile +64 21 968 364, fax +64 7 849 >> 7855 >> Fonterra Co-operative Group Limited >> PO Box 459, Hamilton, 3240, Automation and Process Control, Fonterra Te >> Rapa, SH1, Hamilton, New Zealand >> >> [image: droplet-03] >> >> >> >> ------------------------------ >> DISCLAIMER >> This email contains information that is confidential and which may be >> legally privileged. If you have received this email in error, please notify >> the sender immediately and delete the email. This email is intended solely >> for the use of the intended recipient and you may not use or disclose this >> email in any way. >> >> _______________________________________________ >> Informix-list mailing list >> Informix-list@iiug.org >> http://www.iiug.org/mailman/listinfo/informix-list >> >> > > > -- > Fernando Nunes > Portugal > > http://informix-technology.blogspot.com > My email works... but I don't check it frequently... > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently...