client full data restore - need help to restore incrementals 1

[ttroxell]

Hi,

We had to restore a w2k client, after two disks in a four disk array failed. We have successfully replaced the disks, and restored the full backup with Networker, but are not sure how to proceed with the restore from the incrementals. The server is a sun 450.

This is our backup schedule.

Thurs, March 4th full backup
Fri, March 5th Skipped
Mon, March 8th level 7 incremental
Tues, March 9th level 6 incremental
Wed, March 10th level 5 incremental

We used browse from the client, to perform the full restore, but when we looked at the browse option for the incrementals from Mon, Tues and Wed, were not sure if we had to choose every folder, as we did in the full restore, or if we have to traverse the folder levels and choose the files that we need to have restored.

Can you help us with this?

Thanks,

 

[TDun]

If you are right about the level numbers, then you are doing differentials. As such, restore the highest number since the full (1 being highest, 9 lowest) and you have recovered all days up to then. If you have any since that, recvoer them, using the same idea).

 

[ttroxell]

We started to restore from incrementals, using the tape from Mon - level 7, but are unsure how to proceed. We selected all the files from the browse of that tape, and it appeared that it was trying to run the full restore again. We stopped the restore, and temporarily restored folders that we know were not on the full backup, using the incrementals tapes in sequence mon, tues, wed. Is that how we have to restore any files that were backed up incrementally on those days?

Is there a way to restore only those files that we know were backed up during the incremental backups? If so, can you tell us the proceedures?

Thanks,

 

[605]

- Find out the correcpongding save set id
- Do a save set recovery to a temporary directory
- Recover your files from there

 

[ttroxell]

We've never done a saveset restore. Can you tell me command sequence for it? Can I run it from the client(w2k), or do I have to run it from the server(sun)? Also, I will need to know how to redirect the restore to the temp location.

I got the saveset id's from the volume information for March 5-10, from networker on the client. Is that all I need for the saveset restore?

Thanks,

 

[605]

You can do this from the GUI but i personally prefer the command line.

1. step: find the save set id
mminfo -q "query" -r "ssid"

2. step: start the recovery
recover [-s server] -S ssid [options]

Please have a look at the manual pages (command line reference) for more details. They are very useful!

 

[DavinaTreiber]

ttroxell,

I think you've misunderstood the concept of fulls and incrementals in NetWorker. You don't need to restore from the full, you just select a date to restore from and NetWorker will do the rest. It will take just the files it needs from the full and then just the files it needs from each subsequent incremental or differential backup. This is what is known as a point-in-time recovery.

By recovering from the full, you have not achieved this. You have recovered all files that existed at the time of the full. If you then apply an incremental on to this (perhaps by running a save set recover), you have a superset of the two backups, i.e. you have also recovered any files that might have been deleted in the mean time, probably not exactly what you wanted. You also end up recovering an awful lot more data because you will have recovered some files multiple times and overwritten them each time.

There are times when multiple save set recovers are the only way, e.g. if you have a corrupted CFI, however I don't think your case is one of these.

It seems you have been trying to make life difficult for yourself. However having restored the full backup you're in a bit of a difficult situation. You have the choice of deleting the recovered data and starting again, or of restoring from a date just after the latest incremental, in which case you will overwrite lots of files and end up with more restored data than you should have.

I hope this makes sense, if nothing else it should help you the next time you are in this situation. NetWorker is cleverer than you thought.

 

[fazil1]

Best to
restore oldest FULL first
then
subsiquent incrementals and overwright them, you will end up with most current incremental at the end

 

[DavinaTreiber]

fazil1, that's the obvious way that you would expect to do a save set recover of fulls and incrementals, assuming that you couldn't do a proper index based recovery as NetWorker would.

However, when you think about it a bit more, there are certain advantages to doing it the opposite way round. By that I mean to restore the most recent incremental first, then the next oldest in turn, but not overwriting any files that have already been restored. The advantages of this are:

(1) You write less data back to disk since you only restore each file once, thus it is more efficient.

(2) You recover the most recently modified files first, these are probably the ones most likely to be required urgently.

Wouldn't you agree?

 

[ttroxell]

Thanks everyone for all your suggestions.

At this time, we have decided to stay with the restore from the full backup of March 4th. We have restored selected files from the incremental backups, that users have requested. In the future, we will try a restore as suggested by DavinaTreiber, by performing a point in time recovery.

 

[DavinaTreiber]

ttroxell, if I could make a suggestion, why not set up a test client with a small number of files and create a smaller version of the scenario. Do a full backup, change some files and do an incremental, perhaps repeat this again. Then you can try a full restore from a combination of full and incrementals and see how it works. Much better to try this with unimportant data when the pressure is off.

 

[fazil1]

Hello,
I would agree with Devina it's a good way to do a restores, just keep this in mind though that this approch may be better suited for File servers, but when you are talking about system files or other configuration specific files, the server or the programs may not work correctly untill all files are restored as on original server, since incremental restores would only restore files that have changed, by restoring them first you are being more efficient but not nessasarily complete as some programs would fail to load.
Otherwise it's a exicellent suggestion