Sorry…

1 - But limits are things that we need to respect in life; 2 - If you have U$10K and do not know how to handle it, U$10M is not the answer for you. Because one cent is overflow in both cases; 3 - That is the same for computer resources; 4 - ...
Continue Reading »
image-2285
image-2285

Fake…

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 ...
Continue Reading »
image-2264
image-2264

I would like to understand…

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 ...
Continue Reading »
image-2197
image-2197

Disksort vs Max_Pending

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 ...
Continue Reading »
image-2136
image-2136

Elevator Algorithm II

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 ...
Continue Reading »
image-2038
image-2038

Elevator Algorithm

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 ...
Continue Reading »
image-1997
image-1997

Performance II

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 ...
Continue Reading »