Today my Couch (1.0.1) took a turn for the worse. Couchdb seemed to be
stuck in some sort of error loop which rendered all databases useless.
I managed to isolate the problem to a specific database which was
causing the following error.

[Thu, 11 Oct 2012 17:26:02 GMT] [error] [<0.595.0>] ** Generic server
<0.595.0> terminating
** Last message in was {pread_iolist,170475046269}
** When Server state == {file,{file_descriptor,prim_file,{#Port<0.2136>,23}},
                              0,170475073648}
** Reason for termination ==
** {{badmatch,{ok,<<99,111,109,104,2,110,5,0,186,181,74,98,39,104,2,98,0,0
                           ....SNIP...
                    106,97,0,100,0,3,110,105,108,100,0,3,110,105,108,98,0,0,
                    3,232>>}},
    [{couch_file,read_raw_iolist_int,3},
     {couch_file,handle_call,3},
     {gen_server,handle_msg,5},
     {proc_lib,init_p_do_apply,3}]}

I stopped couchdb and moved the entire .couch file out of the database
directory and then started couchdb. After that couchdb appeared to be
normal with the other databases. The database in questions is ~159GB
with ~9M documents and each document has 2-10 attachments.

I have recently been running up against some system_limit errors which
may have something to do with this although I have not seen any of
these errors today. I'm also trying to track down what system_limit
I'm hitting. If it was open files wouldn't it be a emfile error?

** {{badmatch,{error,system_limit}},
    [{couch_file,sync,1},
     {couch_db_updater,commit_data,2},
     {couch_db_updater,update_docs_int,5},
     {couch_db_updater,handle_info,2},
     {gen_server,handle_msg,5},
     {proc_lib,init_p_do_apply,3}]}


Any thoughts or suggestions would be appreciated.

-Jason