Linux: "dstat" Tool of the day

What is dstat? dstat is a versatile replacement for vmstat, iostat and ifstat.

Dstat allows you to view all of your system resources instantly. Eg, You can compare disk usage in combination with interrupts from your HDD controller, or compare the network bandwidth numbers directly with the disk throughput (in the same interval).

No blog post pimping a cool tool would be complete without the obligatory screen shot.

Unix: Filesystem hierarchy in Unix/Linux/OS X

Although it is one of the first chapters one read when starting with Linux/Unix, it is always confusing where should we put what when it comes to installing stuff on Linux/OS X computers.

I found a detailed reference Filesystem Hierarchy standard website.

It is also worth knowing, why is it important to store any new customized apps in /usr/local.

How RAID 6 works?

RAID 6 is designed for tolerating two simultaneous HDD failures by storing two sets of distributed parities. Apparently the complex mechanism is likely to compromise data rate in and out of the system. With direct support from Intel IOP, Enhance has enabled RAlD 6 in both DAS series and iSCSI series with minimal performance hit. RAlD 6 significantly enhances the reliability of the new EnhanceRAID family even both are built upon low-cost high capacity SATA drives.

Brief
RAID 6 is designed for tolerating two simultaneous HDD failures by storing two sets of distributed parities. Apparently the complex mechanism is likely to compromise data rate in and out of the system. With direct support from Intel IOP, Enhance has enabled RAlD 6 in both DAS series and iSCSI series with minimal performance hit. RAlD 6 significantly enhances the reliability of the new EnhanceRAID family even both are built upon low-cost high capacity SATA drives.

Pro

• Designed for tolerating two simultaneous HDD failures by storing two sets of distributed parities.

Con

• For RAID 6, one needs a more complex system with a method for encoding, as well as XOR calculations. For that, one really needs hardware acceleration, otherwise the performance suffers.
• Uses 2 drives for parity

Recommended Configuration

• Disk array consists of 12 disks or more

Recommended Solutions

• Desktop: EnhanceRAID T8
• Rackmount: EnhanceRAID R14; UltraStor RS16