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Displaying posts with tag: SAS (reset)
Hard Drive Reliability

Cloud service provider Backblaze has updated its earlier study of hard drive failure rates (Nov 2013) in its own infrastructure – from 27,000 to more than 34,000 drives, and the new report (Sep 2014) is quite informative. Hitachi comes out pretty high, Western Digital has produced some good drives, but Seagate tends to come out worst. Each brand does have good and not-so-good models so there’s no single right answer, and for any new model you’ll always be dealing with an unknown factor.

Backblaze also found that consumer drives actually perform well compared to enterprise grade drives, and once price is taking into account the enterprise drives just …

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The Data Day, A few days: April 29-May 3 2013

Teradata Q1 disappoints. Actian acquires ParAccel. And more.

For 451 Research clients: Acquisitive Actian adds ParAccel to its growing database portfolio

— Matt Aslett (@maslett) April 29, 2013

For 451 Research clients: Tokutek releases TokuDB database storage engine as open source

— Matt Aslett (@maslett) May 1, 2013

For 451 Research clients: Codership replicates partnership success with Galera Cluster for MySQL

— Matt Aslett (@maslett) May …

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Green HDs and RAID Arrays

Some so-called “Green” harddisks don’t like being in a RAID array. These are primarily SATA drives, and they gain their green credentials by being able reduce their RPM when not in use, as well as other aggressive power management trickery. That’s all cool and in a way desirable – we want our hardware to use less power whenever possible! – but the time it takes some drives to “wake up” again is longer than a RAID setup is willing to tolerate.

First of all, you may wonder why I bother with SATA disks at all for RAID. I’ve written about this before, but they simply deliver plenty for much less money. Higher RPM doesn’t necessarily help you for a db-related (random access) workload, and for tasks like backups which do have a lot of speed may not be a primary concern. SATA disks have a shorter command queue than SAS, so that means they might need to seek more – however a smart RAID controller would already arrange its I/O …

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Showing entries 1 to 3