[스크랩] 솔라리스 IOPS 확인

http://unix.derkeiler.com/Newsgroups/comp.sys.sun.admin/2007-03/msg00071.html

 

On 2007-03-09 16:59:43 +0000, "lazyboy_2k@xxxxxxxxx" <lazyboy_2k@xxxxxxxxx> said:

 

# iostat -xcnCXTdz 5

아마 r/s, w/s 는 초당 read건수, write건수이고

kr/s, kw/s 는 바이트양

 

When I read the output of iostat -xcnCXTdz 5, I don't
understand what is a distinct difference between r/s vs. kr/s and also
w/s vs. kw/s, and yes, I did read the iostat man page.

r/s and w/s are the number of read and write operations for the thing (see below for meaning of "thing") you're looking at. kr/s and kw/s are the number of kbytes read or written per second. dividing one by the other gives you the average transfer size.

When you are
calculating IOPS, are you looking at r/s or kr/s field?

for IOPS r/s and w/s. However depending on the load on the machine the bandwidth may also be interesting (though IOPS is more commonly an issue for, say, transactional database loads).

Now, in term
of the total IOPS, are we looking a disk as lun or how does it go?

This depends enormously on what I think of as the geometry of the storage (what the "thing" is above). Typically a given disk will have limits on what it can do, both in terms of IOPS and bandwidth, but if you are using any kind of RAID this may be obscured as spindles are combined together in various ways which affect the performance. If you're using purely software RAID (SVM or ZFS) then you have the luxury of being able to see down to the individual spindles very easily. If you're using systems with hardware RAID then this is harder (though the array itself may well support inspection tools in that case). You also have to be aware of multiple Solaris devices which are really the same device - such as slices or soft partitions, but also multiple LUNs made available from the same group of disks from some hardware device. Finally there may be limits imposed by the controller and the interconnect.

You mention about a book which talks about I/O property.., do you
happen to know the name or url that I read it online? I really
appreciated your inputs.

The only reference I can think of off the top of my head is Hennesey and Patterson, but that doesn't really talk about storage in any detail. There must be better books.

If this is a major upgrade (rather: if it's an expensive upgrade) I'd consider getting some specialist consultancy (but not from anyone who wants to sell you storage, because you know what they will say).

--tim