[OpenAFS] Linux + 32bit files + butc writing to file = obnoxiousness

[Robin Yamaguchi]

Hello All:

My backups write to file, and regardless of what i put in tapeconfig, butc
can't write more then 2GB.  I am running 2.4.20-8, ext3, afs 1.2.9 for
redhat 9, so I should be able to surpass this filesize limit.  Is this
limit hardcoded in butc?

Another problem i'm having involves high CPU load and AFS crashing.  I've
been running butc manually, backgrounding the process, and killing the
console window.  When backup dumps tries to run, and the dump file exsists,
butc prompts for another tape.  However, since I don't have console access,
butc freaks out and runs at 99% cpu usage.  Letting this process run for
about an hour leads to my afs server crashing.  AFS clients report
"connection timed out" and rxdebug fails with code -1.

strace -p butc shows:
futex(0x80e7454, FUTEX_WAIT, 627, NULL) = 0
gettimeofday({1052510584, 572087}, NULL) = 0
time(NULL)                              = 1052510584
gettimeofday({1052510584, 572435}, NULL) = 0
sendmsg(5, {msg_name(16)={sa_family=AF_INET, sin_port=htons(32776),
sin_addr=inet_addr("128.111.123.3")},
msg_iov(2)=[{"\244\240aZ\372\377\347$\0\0\0\2\0\0\0\1\0\0\0\2\1\4\0\0"...,
28}, {"\0\0\0D\0\0\0u\0\0\0m\0\0\0p\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 536}],
msg_controllen=0, msg_flags=0}, 0) = 564

Intrestingly, afs crashed with simular symptoms when I attempted to tar/gz
about 3 gigs worth of localfiles on the afs server, none of which was afs
data, onto a mounted nfs share.  This makes me wonder if afs is crashing in
relation to high CPU usage, not to just butc.

Any ideas, pointers, suggestions would be highly appriciated.

thanks,
Robin

--------------------------
Robin H. Yamaguchi
Physics Computing Services
UC Santa Barbara
805-893-8366
--------------------------

On Tue, 30 Jul 2002, J Maynard Gelinas wrote:

>    Hi,
>
>    I've configured butc to write to a file using a secondary port offset,
> this is well documented and easy enough to do. However, because Linux has
> a filesize limit of 2GB (signed 32bits) on IA-32, every time the backup
> file hits 2GB butc prompts to replace the tape. I suppose I could write an
> expect script to move the backup file aside and then let butc know it's
> time to continue writing the backup dump out, but that is a most obnoxious
> solution. Seems to me the right way to go about this is to build large
> file support in the kernel and libc, and then recompile butc. Has anyone
> actually done this? And with what filesystem? XFS is known to support
> large files well, but it's unclear to me how the XFS patches would effect
> building and running the AFS kernel modules.
>
>    I'm already writing out to tape. I just want secondary dumps written
> out to disk for quick restores. Suggestions?
>
> Cheers,
> --Maynard
>
>