[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

[Linux-cluster] Behavior of "statfs_fast" settune



Hello GFS developers,

I am in the process of evaluating the performance gain of
the "statfs_fast" patch.
Once the FS is mounted, I perform "gfs_tool settune  ...." and then i
measure the time to perform "df" on a partially filled FS. The time is
almost the same, "df" returns almost instantly, with a value really
near the truth, and progressively reaching the true one.

But I have noticed that when the FS size increases, the time to
perform  "gfs_tool settune  ...." increases dramatically. In fact,
after a few measures, it appears that the time to perform "df" without
fuzzy statfs is the same as the time to activate fuzzy statfs. 

I've read the patch, and from what I understand, there is an inode used
to store the fuzzy value of statfs, read once and updated later in
background. So the behavior i experienced shouldn't happen. So, please,
what am I doing wrong ?

--
Mathieu


--------------------------------------------------------------------------------
Les opinions et prises de position emises par le signataire du present
message lui sont propres et ne sauraient engager la responsabilite de la
societe SEANODES.

Ce message ainsi que les eventuelles pieces jointes constituent une
correspondance privee et confidentielle a l'attention exclusive du
destinataire designe ci-dessus. Si vous n'etes pas le destinataire du
present message ou une personne susceptible de pouvoir le lui delivrer, il
vous est signifie que toute divulgation, distribution ou copie de cette
transmission est strictement interdite. Si vous avez recu ce message par
erreur, nous vous remercions d'en informer l'expediteur par telephone ou de
lui retourner le present message, puis d'effacer immediatement ce message de
votre systeme.


The views and opinions expressed by the author of this message are personal.
SEANODES shall assume no liability, express or implied for such message.

This e-mail and any attachments is a confidential correspondence intended
only for use of the individual or entity named above. If you are not the
intended recipient or the agent responsible for delivering the message to
the intended recipient, you are hereby notified that any disclosure,
distribution or copying of this communication is strictly prohibited. If you
have received this communication in error, please notify the sender by phone
or by replying this message, and then delete this message from your system. 


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]