Hi ZFSers,
I''ve been working on merging the Joyent arcstat enhancements with some
of my own
and am now to the point where it is time to broaden the requirements gathering.
The result
is to be merged into the illumos tree.
arcstat is a perl script to show the value of ARC kstats as they change over
time. This is
similar to the ideas behind mpstat, iostat, vmstat, and friends.
The current usage is:
Usage: arcstat [-hvx] [-f fields] [-o file] [interval [count]]
Field definitions are as follows:
mtxmis : mutex_miss per second
arcsz : ARC size
mrug : MRU ghost list hits per second
l2hit% : L2ARC access hit percentage
mh% : Metadata hit percentage
l2miss% : L2ARC access miss percentage
read : Total ARC accesses per second
l2hsz : L2ARC header size
c : ARC target size
mfug : MFU ghost list hits per second
miss : ARC misses per second
dm% : Demand data miss percentage
hsz : ARC header size
dhit : Demand data hits per second
pread : Prefetch accesses per second
dread : Demand data accesses per second
l2miss : L2ARC misses per second
pmis : Prefetch misses per second
time : Time
l2bytes : Bytes read per second from the L2ARC
pm% : Prefetch miss percentage
mm% : Metadata miss percentage
hits : ARC reads per second
throt : Memory throttles per second
mfu : MFU list hits per second
l2read : Total L2ARC accesses per second
mmis : Metadata misses per second
rmis : recycle_miss per second
mhit : Metadata hits per second
dmis : Demand data misses per second
mru : MRU list hits per second
ph% : Prefetch hits percentage
eskip : evict_skip per second
l2size : L2ARC size
l2hits : L2ARC hits per second
hit% : ARC hit percentage
miss% : ARC miss percentage
dh% : Demand data hit percentage
mread : Metadata accesses per second
phit : Prefetch hits per second
Some questions for the community:
1. Should there be flag compatibility with vmstat, iostat, mpstat, and friends?
2. What is missing?
3. Is it ok if the man page explains the meanings of each field, even though it
might be many pages long?
4. Is there a common subset of columns that are regularly used that would
justify
a shortcut option? Or do we even need shortcuts? (eg -x)
5. Who wants to help with this little project?
--
Richard Elling
richard at nexenta.com +1-760-896-4422
Nexenta European User Conference, Amsterdam, May 20
www.nexenta.com/corp/european-user-conference-2011
Hello Richard!> I''ve been working on merging the Joyent arcstat enhancements with some of my > own and am now to the point where it is time to broaden the requirements > gathering. The result is to be merged into the illumos tree.Great news!> 1. Should there be flag compatibility with vmstat, iostat, mpstat, and > friends?Don''t bother. I find that I need to look at the man page anyway if I want to do anything that goes beyond -i 1. :-)> 2. What is missing?Nothing obvious to me.> 3. Is it ok if the man page explains the meanings of each field, even though it > might be many pages long?Yes please!!> 4. Is there a common subset of columns that are regularly used that would justify > a shortcut option? Or do we even need shortcuts? (eg -x)No. Anything I need more than 1-2 times I wil turn into a shell alias anyway ("alias zlist zfs list -tall -o mounted,mountpoint,name" :-).> 5. Who wants to help with this little project?My first reaction was ENOTIME. :-( What kind of help do you need? Regards -- Volker -- ------------------------------------------------------------------------ Volker A. Brandt Consulting and Support for Oracle Solaris Brandt & Brandt Computer GmbH WWW: http://www.bb-c.de/ Am Wiesenpfad 6, 53340 Meckenheim Email: vab at bb-c.de Handelsregister: Amtsgericht Bonn, HRB 10513 Schuhgr??e: 46 Gesch?ftsf?hrer: Rainer J. H. Brandt und Volker A. Brandt
On Mon, Apr 25, 2011 at 11:58 PM, Richard Elling <Richard.Elling at nexenta.com> wrote:> Hi ZFSers, > I''ve been working on merging the Joyent arcstat enhancements with some of my own > and am now to the point where it is time to broaden the requirements gathering. The result > is to be merged into the illumos tree. > > arcstat is a perl script to show the value of ARC kstats as they change over time. This is > similar to the ideas behind mpstat, iostat, vmstat, and friends. > > The current usage is: > > ? ?Usage: arcstat [-hvx] [-f fields] [-o file] [interval [count]] > > ? ?Field definitions are as follows:[Lots of ''em.]> Some questions for the community: > 1. Should there be flag compatibility with vmstat, iostat, mpstat, and friends?Beyond interval and count, I''m not sure there''s much in the way of commonality. Perhaps copy -T for timestamping.> 2. What is missing? > > 3. Is it ok if the man page explains the meanings of each field, even though it > might be many pages long?Definitely. Unless the meaning of each field is documented elsewhere.> 4. Is there a common subset of columns that are regularly used that would justify > a shortcut option? Or do we even need shortcuts? (eg -x)If I was a user of such a tool, I wouldn''t know where to start. Which fields ought I to be looking at? There are a whole bunch of them. What I would expect is a handful of standard reports (maybe one showing the sizes, one showing the ARC efficiency, another one for L2ARC).> 5. Who wants to help with this little project?I''m definitely interested in emulating arcstat in jkstat. OK, I have an old version, but it''s pretty much out of date and I need to refresh it. -- -Peter Tribble http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/
Thanks Peter, On Apr 26, 2011, at 2:16 PM, Peter Tribble wrote:> On Mon, Apr 25, 2011 at 11:58 PM, Richard Elling > <Richard.Elling at nexenta.com> wrote: >> Hi ZFSers, >> I''ve been working on merging the Joyent arcstat enhancements with some of my own >> and am now to the point where it is time to broaden the requirements gathering. The result >> is to be merged into the illumos tree. >> >> arcstat is a perl script to show the value of ARC kstats as they change over time. This is >> similar to the ideas behind mpstat, iostat, vmstat, and friends. >> >> The current usage is: >> >> Usage: arcstat [-hvx] [-f fields] [-o file] [interval [count]] >> >> Field definitions are as follows: > > [Lots of ''em.] > >> Some questions for the community: >> 1. Should there be flag compatibility with vmstat, iostat, mpstat, and friends? > > Beyond interval and count, I''m not sure there''s much in the way of commonality. > Perhaps copy -T for timestamping.The Joyent code (and the original, IIRC) had a "time" field. I''ve added a "date" field, too. However, in both cases the format is fixed. I''d rather make that localized in some meaningful manner, more like the "-T d" options.> >> 2. What is missing? >> >> 3. Is it ok if the man page explains the meanings of each field, even though it >> might be many pages long? > > Definitely. Unless the meaning of each field is documented elsewhere.They are floating around the blogosphere, but yes, there is great value in documenting them in a meaningful manner.> >> 4. Is there a common subset of columns that are regularly used that would justify >> a shortcut option? Or do we even need shortcuts? (eg -x) > > If I was a user of such a tool, I wouldn''t know where to start. Which > fields ought > I to be looking at? There are a whole bunch of them. What I would expect is a > handful of standard reports (maybe one showing the sizes, one showing the ARC > efficiency, another one for L2ARC).The ones I usually find interesting are the hit rates and usage. There are many posts in this forum were people ask about how much RAM is needed for L2ARC, metadata, etc. Measurements are better than models. How about a separation in the form: rates (hits,misses,...) rate% (%hits,%misses,...) sizes (c,p,l2size,...) l2arc (l2*)> >> 5. Who wants to help with this little project? > > I''m definitely interested in emulating arcstat in jkstat. OK, I have > an old version, > but it''s pretty much out of date and I need to refresh it.Good idea :-) -- richard -- Richard Elling richard at nexenta.com +1-760-896-4422 Nexenta European User Conference, Amsterdam, May 20 www.nexenta.com/corp/european-user-conference-2011