O treime dintre copiii americani, 15 milioane, mai exact, sunt crescuţi fără tată, iar alţi 5 milioane de copii sunt crescuţi fără mamă, arată un recensământ făcut în SUA în anul 2010


70 de ani


aaron swartz





the next of ssd ultradimm



how to attach a netapp shelf to a server

FWIW I connected a couple of DS14mk2 FC shelves directly to a Solaris machine and noticing that the disk sector size was 520bytes and apart from that I could do nothing with the disks. Recalling a similar issue many years ago with old SAN disks I connected the array to a Linux machine and using sg_format from the sg3_utils package I reformatted the disks with a 512byte sector size (sg_format --format --size=512)
After this I could read and write to the disks on Solaris.

I didn't do much with them because I was actually more interested in getting some DS14mk2 AT disk shelves working - I want the capacity of SATA disks and not the performance of FC disks.
With the AT shelves I could see all the disks in 'format' on Solaris, I could create filesystems but when writing to the disks the I/O performance would dive and give lots of SCSI errors. I was hoping to put a load of low power 2T disks into the shelf to build a multi TB storage pool. The 2T disks were visible to format when put into the disk trays but suffered the same I/O performance and SCSI errors



comparison of oracle replication techniques



exadata speed test



On X2, X3, and X4 systems, high performance disks can execute about 300 small I/Os per second (IOPS) without a
large increase in response time (peak performance is actually above 400 IOPS), or 50,000 IOPS on a full rack. A
large I/O is roughly 3 times as expensive as a small IO. You can determine approximate disk utilization by counting
the total small I/Os and adding the total large I/Os multiplied by 3. Then compare this count to the 300 IOPS
threshold to determine utilization. For 4TB high capacity disks, the IOPS are around 120 and the multiplier for large
I/Os is about 2.
4TB high capacity disks have IOPS around 190 or 32,000 IOPS for a full rack and should also use a 2x multiplier for
large I/Os. For additional Exadata capacity details please reference the Oracle Exadata Database Machine Data
High disk latencies are not necessarily a problem – it depends on how the application is impacted. For a Data
Warehouse it may be perfectly fine for the disks to be running at maximum throughput and latency when processing



Now is where the Pomodoro technique comes in to play. At the core of this approach is the value of focusing for short bursts of activity. Specifically, one chooses a task (or set of tasks) to be completed in 25 minutes, sets a timer for 25 minutes, closes the door, unplugs the phone, turns off IM notifications and closes their email software, and works, diligently, on only the task at hand, for 25 minutes. Then you can take a 5 minute break. 

You might think that a person could do 16 of these cycles in a day. I'm lucky to get more than two in a day without interruptions. But in those 50 minutes I get more done than I do in the other seven hours of my work day, at least in terms of advancing the most important aspects of my most important projects.