disk diagnostics

Bill Hacker wbh at conducive.org
Wed Jul 26 02:52:51 PDT 2006


Pieter Dumon wrote:
Wow, not too fast. I don't have access to my machine right now (I'm at
work), so I will post detailed stats later (timed rm, top output, ...)
- no servers (web,mail,smb,....) are running
- no other users present
- no cron jobs or other daemons or other processes apart from the
standard system processes and X+KDM running.
Ummmhhh.. you are doing a make buildworld, ..kernel,...install... cycle in 
multiuser mode via X+KDM?

- disk room enough for what I'm trying to do, only HDD access to that
HDD needed.
- it's an AMD Sempron 3100+, with Dragonfly on the old disk
How much memory?  How many swap areas, and how large each?

- the 25 minutes was a subjective quantification. But it's O(10min).
- DFly-preview 1.5.4, but got the same problem with older versions
- I did not want to say it is a bug in DFly, no far from that, it just
should be some hardware problem or a configuration issue or something
stupid.
I'll refrain from calling X+<any WM> 'stupid' for an OS make/install cycle, but 
only out of incredulity. There's one hog that should be shut down in favor of a 
simple (ssh-ed) CLI when doing resource-intensive make/build/install work.

*Especially so* if it has a filemanager view window open and is trying to keep 
it current and sorted.

If I remember well, the rm process is spending a lot of time in the
IOWAIT status, but I'm not sure anymore. So, wait for more info to
come later.
OK. Please copy us a 'df' or three as well, just to make sure.

Thanks,

Bill


thanks already,

Pieter

On 7/26/06, Bill Hacker <wbh at xxxxxxxxxxxxx> wrote:

Simon 'corecode' Schubert wrote:

> Bill Hacker wrote:
>
>> Warren Hull 25 minutes delay comes in, and I/O tuning doesn't cover
>> that. Too big a number for where it is being reported as happening.
>>
>> Either something else - probably something *basic* but simply
>> overlooked - is placing demands on that storage system, or the
>> 'problem' has been misreported.
>
>
> softupdates?  writing meta data with sync will be really slow.
>
> cheers
>  simon
>
No, not *that* slow, not even on K6-2-500 with 256 MB of SDRAM, where 
I have
done it on a production FreeBSD 4.8 web & mx box for donkey's years 
(too small
to hold a RAID). DFLY may not have focused on that area, but should 
not be 2 or
3 orders of magnitude slower than 4.9/4.9 BSD.

Especially not that slow on a scripted dirtree rm -Rf

I'd want to see what is in the ~/messages and other logs, (rampant I/O 
errors?),
what, if anything was mounted from the CD's, where mounted, and what 
the path
was at the time - likewise RAMDISK and if df showed one or more mounts
at/near/over 100%+ of capacity, memory and swap stats.... etc.  The 
'usual
suspects'.

The time involved hints at CD's being spun up, paths searched, found 
not to
contain <whatever>, rewind.... or some partition being pushed over 100%
temporarily. Folsks cramming multiple OS test installs onto media all 
too rarely
pay attention to temporary needs. The 8+ GB needed for building 
OpenOffice from
source caught even this old dog flatfooted, for example.

Otherwise, ATA I/O is too 'universal' in use to hide a DFLY bug of such
magnitude for very long, so the paucity of related reports says it is 
a local
'headspace' issue...

Bill






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