Initial NFS Test: Linux vs FreeBSD (769% slower)

[Marc G. Fournier]

On 2013-04-26, at 16:56 , Rick Macklem <rmacklem at uoguelph.ca> wrote:

> If you didn't unmount/remount between writing jboss to the server and
> timing the startup of it, please try it again after doing a dismount/mount.
> (Doing the dismount/mount on the Linux client resulted in the same # of
> reads as FreeBSD for a quick test I did, instead of none without the
> dismount/remount.)

'k, this one was tried on Friday, and even a full server reboot didn't make any difference in performance, whether the first run or subsequent ones … its just  plain fast …


> A few other things to do:
> - Time multiple startups after doing a mount, to see if it only the
>  first one that is slow.

Tried … all are equally slow … best time so far has been ~230s … yup, after several start ups, its pretty consistently around the 240s mark …

> - Capture the RPC counts for both clients by doing "nfsstat -c" before
>  and after the startup.

FreeBSD:

Before:

Client Info:
Rpc Counts:
  Getattr   Setattr    Lookup  Readlink      Read     Write    Create    Remove
  2745853    821481    973901        18   2230947   2098303    160726      4954
   Rename      Link   Symlink     Mkdir     Rmdir   Readdir  RdirPlus    Access
     1862         0         0     14724       950     16272         0    329756
    Mknod    Fsstat    Fsinfo  PathConf    Commit
       12     30873         5         0         0
Rpc Info:
 TimedOut   Invalid X Replies   Retries  Requests
        0         0         0         0   9430761
Cache Info:
Attr Hits    Misses Lkup Hits    Misses BioR Hits    Misses BioW Hits    Misses
 26322016   2745853  20537972    973869   2373488   2225801   2618800   2097243
BioRLHits    Misses BioD Hits    Misses DirE Hits    Misses Accs Hits    Misses
     1262        18     46863     15678     29941         0  22513185    329759

After:

Client Info:
Rpc Counts:
  Getattr   Setattr    Lookup  Readlink      Read     Write    Create    Remove
  2745919    821481    973912        18   2230947   2098303    160726      4954
   Rename      Link   Symlink     Mkdir     Rmdir   Readdir  RdirPlus    Access
     1862         0         0     14724       950     16272         0    329767
    Mknod    Fsstat    Fsinfo  PathConf    Commit
       12     30873         5         0         0
Rpc Info:
 TimedOut   Invalid X Replies   Retries  Requests
        0         0         0         0   9430849
Cache Info:
Attr Hits    Misses Lkup Hits    Misses BioR Hits    Misses BioW Hits    Misses
 26323022   2745919  20538207    973880   2374208   2225801   2618800   2097243
BioRLHits    Misses BioD Hits    Misses DirE Hits    Misses Accs Hits    Misses
     1262        18     46863     15678     29941         0  22513489    329770

Okay, if I'm reading the above right … there doesn't look to be *alot* of difference between the Before n After … it doesn't look like its downing a whole lot of NFS ops … am I reading wrong?

> If the above doesn't give you any good hints w.r.t. why it is slow,
> you can capture packets during the startup for both clients and look
> at them in wireshark, to try and figure out what the difference between
> the Linux and FreeBSD clients are for this case.

If the above nfsstat output indicates this is warranted, then please provide more information on what I should run …