Archives for Dtrace
DNLC is something that did create a lot of discussions on ZFS mailing list, and is one of that parts that ZFS did not changed, and (at least for me) a ghost. Let me try to explain...
ZFS dynamics are totally different from many parts of the other ...
![Fake… image-2285](wp-content/uploads/post-nmt2-300x226.jpg)
![Fake… image-2285](wp-content/uploads/post-nmt2-300x226.jpg)
That was a simple but nice one... i did see a huge write performance on one of our storages.
Take a look at this slog device (SSD):
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
0.0 10494.5 ...
![I would like to understand… image-2264](wp-content/uploads/chimpanzee-150x150.jpg)
![I would like to understand… image-2264](wp-content/uploads/chimpanzee-150x150.jpg)
Maybe if i could understand the Oracle's mind, i could learn how to make money. I think that is the key in this whole Oracle/Sun situation:
Java, Dtrace 1, 2, 3, 4, and ZFS creators did leave the company.
Why someone would buy a technology company, with so many ...
![Disksort vs Max_Pending image-2197](wp-content/uploads/boxe-150x150.gif)
![Disksort vs Max_Pending image-2197](wp-content/uploads/boxe-150x150.gif)
DO NOT TRY IT IN PRODUCTION. USE AT YOUR OWN RISK!
Good news... here you can get a little script to enable, disable, and check the disksort flag on your disks (not persistent after reboot, take a look on my other post to a link for how to do it).
Take ...
![Elevator Algorithm II image-2136](wp-content/uploads/grid-150x150.jpg)
![Elevator Algorithm II image-2136](wp-content/uploads/grid-150x150.jpg)
DO NOT TRY IT IN PRODUCTION. USE AT YOUR OWN RISK!
In my last post i did write about some issues related with disksort:
1) Performance (Latency)
2) Consistency
In my D Script i'm printing the buf sector when the sd driver receives it. So, without sorting.
That's important because i'm ...
![Elevator Algorithm image-2038](wp-content/uploads/pitstop-150x150.jpg)
![Elevator Algorithm image-2038](wp-content/uploads/pitstop-150x150.jpg)
Hello there, this will be a long post... so, i think if you have no time to waste, think again before you go ahead.
And, no. I'm not Morpheus, so i cannot offer you the truth. Actually, i can just offer you my doubts. And no pills, i do ...
![Performance II image-1997](wp-content/uploads/watertowine1-300x300.jpg)
![Performance II image-1997](wp-content/uploads/watertowine1-300x300.jpg)
In my last post about 'Performance', i did talk about a ZFS tuning parameter: zfs_prefetch_disable. And that was a ZFS read parameter...
In this post, we will take a look in another one, with the same 'water to wine' effect. This time with focus on writes...
We have a set ...
![OpenSolaris events @SF 2009 image-1214](pictures/opensolaris/california.jpg)
![OpenSolaris events @SF 2009 image-1214](pictures/opensolaris/california.jpg)
That was an amazing experience, and was really great meet those people that i just talk by email. First was the OHAC Summit, where we had excellent presentations, and the keynote 'The Network is the Cluster' by Dr. David Cheriton (Stanford University), and the 'High Availability: Today and Tomorrow' discussion ...
![NFS – Block Size Monitor (v0.2) image-963](pictures/opensolaris/nmtv0.2-420.jpg)
![NFS – Block Size Monitor (v0.2) image-963](pictures/opensolaris/nmtv0.2-420.jpg)
I need more eyes on the code... ;-)
I did a few more changes, but i'm not a C programmer. I did add two graphs (clean up the screen with curses is boring, thanks for some procedures from iMil and the great wimon software).
With that graphs (Read and Write), we ...
![NFS – Block Size Monitor (DTrace powered) image-906](pictures/opensolaris/nfstoolshot1-400.png)
![NFS – Block Size Monitor (DTrace powered) image-906](pictures/opensolaris/nfstoolshot1-400.png)
DO NOT TRY IT IN PRODUCTION. USE AT YOUR OWN RISK!
Hello there! Yesterday i was coding a simple tool to provide a better visualization of the block's sizes (read/write) on a NFS server. The primary objective was not consolidate informations, but just quickly visualize trends, for a short period of ...