My client has a computing environment that includes six F630's, an F540, and an F330, all doing CIFS, NFS, and quotas. In January, we decided to get them all running the same OS revision, and based on the bug list we chose 5.2.1 as a target.
So we upgraded one of the F630's to 5.2.1 in mid-January to see how it'd do. It did great, so Friday before last we upgraded the remainder of the filers from various 5.1.x flavors to 5.2.1.
At midnight on Saturday night/Sunday morning, all but one of the filers panicked. The F630 that had been up for a month on 5.2.1 joined the group in panicking, but an identical F630, just upgraded the previous day with the rest of the group, did not.
The next day, NAC technical support told us, even before they saw the dump, that this was bug 12363 ("Terminated DC connection causes crash in stub code") which is new to 5.2.1 and occurs when a CIFS-enabled filer loses contact with its domain controller. This bug is fixed in 5.2.1P1. We were skeptical of this diagnosis at first, since we hadn't had any known network events or DC events at that time, but conveniently a filer panicked again on Monday when we tried to delete a share. That data point plus NAC's report on Sunday's dumps, which confirmed their diagnosis of bug 12363, convinced us to begin a careful yet urgent move to 5.2.1P1.
We installed 5.2.1P1 on one of the F630's that had panicked. No problems for the rest of the week. So Sunday we installed 5.2.1P1 on the rest of them.
Two filers (one F630 and the F330) panicked Monday after we did a "quota on" on them. The panics occurred on the same failed assertion: "../common/wafl/quota.c:926: Assertion failure." (Because the "quota on" is part of a script that various folks run frequently, it took two panics before we drew a straight line between the "quota on" and the panic.)
The panics recurred on attempt to reboot. We had to boot off floppy, leaving quotas off.
So now we are running without quotas on the filers that panicked on 5.2.1P1. And we can't do a "quota on" on any of the others; I personally am even afraid of "quota resize". And we are faced with the difficult decision between regressing to 5.1.x (which wasn't a rose garden either) or waiting for a new 5.2.1Px. Either way, we've submitted the most recent dumps to NAC tech support, and we're waiting on a response.
If you are thinking of moving to 5.2.1, I encourage you to think carefully.
Brian