I don’t think this city has been identified, but I ran across its name several times while reading Ur III Texts from the Schøyen Collection, Jacob Dahl.
It’s also listed as one of the cities destroyed by Rimush of the Akkadian dynasty in R2:43 (Warfare and the Ancient Near East to 1600 BC, Hamblin, p. 79).
In a CDLI bulletin, “On the Sumerian City UBmeki, the alleged Umma” by Vitali Bartash (cdli.ucla.edu/pubs/cdlib/2015/cdlb2015_002.html) he says:
Cities and towns in which “Umma” tablets have been excavated, are Jokha (ancient Umma?), Umm al-Aqarib (Giš(š)a ?), Tell Ibzekh (Zabala) and possibly Tell Schmid (KiAN ?).
I can’t find much of anything about Tell Ibzekh or Tell Schmid; I did find Tell Ibzekh and Tell Shmid referred to in the index of The Oxford History of the Ancient Near East Vol 1 as being on its page 540, but that page isn’t in the google books preview so I couldn’t read it. I did notice that chapter was also written by Bartash, however. So Schmid was probably just a typo, but Shmid is not any more informative.
It seems like Zabala/Zabalam and KI.AN were both in the vicinity of Umma because I keep seeing them come up in the same texts, and KI.AN apparently had a temple to the god Šara, whom I’m casually researching.
Anyways, can anyone tell me anything about those two Tells, or anything else about these mystery cities?
Tell Ibzaikh has been identified as ancient Zabalam since the late 50's, based on a brick with an inscription by Hammurabi naming it as Zabalam.
Excavations took place at Tell Shmet in 2001-2002, and only recently information on these excavations is being published. The cuneiform tablets excavated at the site seem to suggest that the site is KI.AN/AN.KI based on the named deities and cultic places, but the reading of the name is yet unknown and a definitive identification of Tell Shmet as KI.AN isn't possible to be made still.
For Tell Ibzaikh I recommend checking the entry for Zabalam in the Reallexikon der Assyriologie, and also W.W. Hallo (1980), "Zabalam = Ibzaikh", Revue d'Assyriologie 74: 94-95.
For Tell Shmet, Fahad & Abbas (2020) "Cuneiform Tablets from Shmet from the Excavation Season of 2001", Zeitschrift für Assyriologie 110: 1-13.