I'll tackle the German case here and leave the Soviet currency reform (or lack thereof) to someone else.

For the GDR, the West Germans created a very generous currency reform in which individuals could exchange Ostmarks (DDM) for Deutsche Marks (DM) on a 1:1 ratio. The East Germans could exchange up 4000 DDMs at this highly favorable ratio; savings over 4000 DDMs could be exchanged at a 2:1 ratio. To discourage speculation, DDMs acquired before shortly before unification had an exchange rate of 3:1. GDR pensions were simply converted over to DM at a 1:1 ratio and debts like housing loans were 2:1. There was a window in which East Germans could convert their savings. The logic of the Kohl government was that a shock economic transition would hasten the economic reintegration of the two Germanies.

In a sense, the East Germans did lose all of their money, but in return they gained a far more valuable currency. The DDM could only be legally spent within the GDR and its unofficial exchange rate with the DM fluctuated in the black market, hovering around 5:1 or worse. The overall success of the currency reform is a bit mixed. On one hand, it did swiftly reintegrate the country economically and it forestalled any political embarrassments such as pauperizing pensioners. However, part of the currency reform was it also converted GDR wages from DDM to DM on a 1:1 basis. This had the effect of pricing the eastern half of Germany out of the market for a good decade since the former East Germany had a dilapidated economic infrastructure that made it much more inefficient compared to the west.

The best book on the GDR's money and the rather basketcase economic policies is The Currency of Socialism: Money and Political Culture in East Germany by Jonathan Zatlin.

As for Russia, the Soviet ruble was in circulation until 1993, when the monetary reform took place. Until then the currency remained the same as in the USSR, but there was hyperinflation, so the money wasn't worth anything close to what it was worth then.

The new currency was the Russian ruble. The reform was confiscatory meaning that people had to exchange their old notes for the new ones in a certain period of time. The sum to exchange was limited. The money that couldn't be exchanged, became just paper.

You can read the summary of what happened in Russia here: https://en.wikipedia.org/wiki/Monetary_reform_in_Russia,_1993 (I kindly ask the mods not to delete my comment solely because of the wiki link. It's the most concise source available in English. If Russian sources can be of help to anybody, I will be happy to provide the links).

Some research can be found in this paper: https://www.google.ru/url?sa=t&source=web&rct=j&ei=gn35VLyaKePFygOp34DwCA&url=http://www.cato.org/cato-journal/winter-1993/monetary-reform-russia-case-gold&ved=0CC0QFjAB&usg=AFQjCNEiAdpfHtLybeC2PpdGf5YyqNlp3g&sig2=5EmRHvlfDs0ht6vEH-1Q8g (link to download pdf)