home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: comp.unix.ultrix
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!destroyer!news.iastate.edu!john
- From: john@iastate.edu (John Hascall)
- Subject: Re: SCSI/CAM problems
- Message-ID: <1992Sep5.011659.7675@news.iastate.edu>
- Sender: news@news.iastate.edu (USENET News System)
- Organization: Iowa State University, Ames, IA
- References: <ROBM.92Sep4150116@ataraxia.Berkeley.EDU>
- Date: Sat, 5 Sep 1992 01:16:59 GMT
- Lines: 52
-
- robm@ataraxia.Berkeley.EDU (Rob McNicholas) writes:
-
- }I've recently installed the Open SCSI/CAM software on my DECstation,
- }and I'm suddenly having some inexplicable (by me) problems with my
- }tape drives. Here's the scenario:
- ...
- }We now seem to get an inordinate number of CAM errors occurring
- }randomly during dumps, as well as reproducible errors from certain
- }utilities. Attached at then end of this message is sample output from
- }uerf and cam_report.
-
- }Anyone having similar experiences? Anyone have any suggestions?
- Yes, yes, yes! No (sorry).
-
- We upgraded our central NFS servers from 5000/200s to 5000/240s
- and since we had to upgrade from 4.2, we installed the SCSI/CAM
- at the same time. Our machines have 2 or 3 SCSI boards, 8-12 RZ57s,
- and a TLZ04 each (the DEC support guy said he thought the other
- problem report he had on this also was a multi-SCSI machine).
-
- What happens is we start getting *tons* of:
- XPT Packet Pool HIGH Water Mark Reached.
- cam_logger: CAM_ERROR packet
- cam_logger: No associated bus target lun
- messages on the console and also (in the two times I have seen it happen)
- the dreaded "cant get mbufs" message also appears. It seems to be somehow
- related to uptime (memory leak?) and load (so, of course, today, with a
- machine which hung last night and being the Friday before a long weekend,
- we had neither and I couldn't reproduce it for DEC *sigh*).
-
- We noticed this because we started getting more and more complaints about
- I/O to the NFS servers slowing down more and more. So I ran the "iozone"
- benchmark around 2pm and got horrid numbers, later in the afternoon they
- were even lower, after dinner I decided to run it directly on the server
- (thinking we had some sort of NFS problem at first). I happened to login
- on the console to do this and the CAM errors just cam pouring out and then
- they stopped (little grey button time).
-
- }If I decide to back out on this "upgrade", will I have to reinstall
- }the 4.2A kernel config files? (I'd hate to have to do that since I've
- }since installed a bunch of patches.)
-
- I was told that backing out of SCSI/CAM was NOT as simple as
- just "setld -d ..." If we can't get a fix by next week we are
- resigned to going backwards to 4.2a.
-
- John
- --
- John Hascall ``Live with it pink-boy!''
- Project Vincent
- Iowa State University Computation Center john@iastate.edu
- Ames, IA 50011 515/294-9551 [fax -1717]
-