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Displaying posts with tag: storage (reset)
The Puzzling Performance of the Samsung 960 Pro

In this blog post, I’ll take a look at the performance of the Samsung 960 Pro SSD NVME.

First, I know the Samsung 960 Pro is a consumer SSD NVME drive, not intended for sustained data center workloads. But the AnandTech review looked good enough that I decided to take it for a test spin to see if it would work well with MySQL benchmarks.

Before that, I decided to do a simple sysbench file IO test to see how the drives handled sustained workloads, and if it would start acting up.

My expectation for a consumer SSD drive is that its write consistency will suffer. Many of those drives can sustain high bursts for short periods of time but have to slow down to keep up with write leveling (and other …

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Using NVMe Command Line Tools to Check NVMe Flash Health

In this blog post, I’ll look at the types of NVMe flash health information you can get from using the NVMe command line tools.

Checking SATA-based drive health is easy. Whether it’s an SSD or older spinning drive, you can use the


 command to get a wealth of information about the device’s performance and health. As an example:

root@blinky:/var/lib/mysql# smartctl -A /dev/sda
smartctl 6.5 2016-01-24 r4214 [x86_64-linux-4.4.0-62-generic] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke,
SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
 1 Raw_Read_Error_Rate     0x002f   100   100   000 …
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How to Move a MySQL Partition from One Table to Another

In this blog post we’ll look at how to move a MySQL partition from one table to another, for MySQL versions before 5.7.

Up to version 5.7, MySQL had a limitation that made it impossible to directly exchange partitions between partitioned tables. Now and then, we get questions about how to import an .ibd for use as a partition in a table, as well as how to exchange partitions with another partitioned table. Below is step-by-step instructions on how to move a partition from one table to another.

In this example, one of our customers had two tables with the following structures:

CREATE TABLE live_tbl (
some_id bigint(20) NOT NULL DEFAULT '0',
summary_date date NOT NULL,
PRIMARY KEY (some_id,summary_date)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
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Don’t Spin Your Data, Use SSDs!

This blog post discussed the advantages of SSDs over HDDs for database environments.

For years now, I’ve been telling audiences for my MySQL Performance talk the following: if you are running an I/O-intensive database on spinning disks you’re doing it wrong. But there are still a surprising number of laggards who aren’t embracing SSD storage (whether it’s for cost or reliability reasons).

Let’s look at cost first. As I write this now (September 2016), high-performance server-grade spinning hard drives run for about $240 for 600GB (or $0.40 per GB).  Of course, you can get an 8TB archive drive at about same price …

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Testing Samsung storage in tpcc-mysql benchmark of Percona Server

This blog post will detail the results of Samsung storage in


 benchmark using Percona Server.

I had an opportunity to test different Samsung storage devices under tpcc-mysql benchmark powered by Percona Server 5.7. You can find a summary with details here

I have in my possession:

  • Samsung 850 Pro, 2TB: This is a SATA device and is positioned as consumer-oriented, something that you would use in a high-end user desktop. As of this post, I estimate the price of this device as around $430/TB.
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MySQL Enterprise Backup (MEB) and Oracle Storage Cloud

MEB 3.12.0 and above support cloud backup and restore using OpenStack-compatible object stores ("Swift"). This allows MySQL database users with Oracle Storage Cloud account to take backups and store them directly in the cloud and restore them from there.

The following steps illustrate how to set up and use MEB with Oracle Storage Cloud :

1) Create Oracle Storage Cloud account at . Once service gets activated, make a note of the following credentials that will be required in further steps :

  • Username

  • Password

  • Identity domain name

  • Service Instance Name : Customer-specified name of the service instance

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Storage caching options in Linux 3.9 kernel

dm-cache is (albeit still classified “experimental”) is in the just released Linux 3.9 kernel. It deals with generic block devices and uses the device mapper framework. While there have been a few other similar tools flying around, since this one has been adopted into the kernel it looks like this will be the one that you’ll be seeing the most in to the future. It saves sysadmins the hassle of compiling extra stuff for a system.

A typical use is for an SSD to cache a HDD. Similar to a battery backed RAID controller, the objective is to insulate the application from latency caused by the mechanical device, the most laggy part of which is seek time (measured in milliseconds). Giventhe  relatively high storage capacity of an SSD (in the hundreds of GBs), this allows you to mostly disregard the mechanical latency for writes and that’s very useful for database systems such as MariaDB.

That covers writes (for the moment), but …

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The “Big Data” buzzword finally gets a real definition

We’ve all heard the term “Big Data” thrown around a fair amount in the last several years ever since the rise of Hadoop and other distributed storage methods. But defining “Big Data” has always been a subjective term that hinges on perspective; what one engineer considers big can be vastly different than another’s.

However, there’s finally a definite description that says Big Data no matter what perspective you operate from: “That facility by my calculations that I submitted to the court for the Electronic Frontiers Foundation against NSA would hold on the order of 5 zettabytes of data. Just that current storage capacity is being advertised on the web that you can buy. And that’s not talking about what they have in the near future.” You can read more about the facility and its purpose here: …

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Speaking at LinuxCon Europe 2012 in Barcelona (Nov. 5-9)

I feel like I just got back home from Oracle OpenWorld (check out my pictures) and some vacation, but I'll be on the road again next week to attend LinuxCon Europe in Barcelona. I'll be there from Monday (Nov. 5th) until Wednesday evening. Oracle is sponsoring the event and we'll have a booth at the exhibition area (booth #19), handing out free Oracle Linux and Oracle VM DVDs. I'll be at the booth every now and then and plan to give a short introduction and live demo of Ksplice rebootless updates on Monday evening (6:00pm).

Two …

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The blog was down yesterday

The brief outage was due to a scheduled move of the servers to a separate rack and subnet dedicated to our work with the Center for Information Assurance & Cybersecurity (ciac) at the University of Washington Bothell (uwb), and

I am currently exercising the new (to us) equipment and hope to winnow the less than awesome equipment over the next quarter. I spent the last six months finding the best in breed of the surplussed DL385 and DL380 chassis we (work) were going to have recycled. The team and I were able to find enough equipment to bring up one of each with eight and six gigs of memory, respectively. These will make excellent hypervisors for provisioning embedded instances of Slackware, Fedora, RHEL, CentOS, Debian, FreeBSD, OpenSolaris, OpenIndiana, FreeDOS, etc.

When I initially configured this xen paravirt environment, I failed to plan for integration with libvirt, so I am now re-jiggering the software bridges so …

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