We have a NW 6.5 SP7 server where we were burning large amounts of files an then deleting them. Day before yesterday while we were doing this we got the following error:

NSS-2.70-5009: Pool <server>/SYS had an error
(20012(beastTree.c[510])) at block 66(file block -66) (ZID 1).

NSS-2.70-5008: Volume <server>/SYS had an error
(20012(beastTree.c[510])) at block 66(file block -66) (ZID 1).

We have not had any problems with this server before. However I understand we may be having one now. There is only 1 Pool there - SYS and it is 750GB but only has about 200 used. My question regards what is the best path. From what I read we should update to SP8 and it (may) fix it - but likely not. We would need to do a NSS /poolverify and then, if needed, do NSS /poolrebuild? From what I read the pool rebuild seems to be a very risky thing to do because alot of folks lose data when they do this or crater the whole pool. What is the best suggestion that any of you have as I have not had to face this before? We were planning on doing this over the weekend (Memorial Day) because it seems to be fairly unknown how long the verify or rebuild would take and we don't have many 12+ hour windows in order to do this. Thank you in advance.