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Displaying posts with tag: lvm (reset)
How to expand a striped LVM database volume in Amazon AWS without downtime

This procedure can be used to expand an LVM  database volume on Amazon AWS (but also apply to any storage area network environment equally). Let me start with this assumption: when you create volumes for database use in AWS using EBS, you stripe data across them in order to enhance performance.  If you aren't doing this... well, you should :-) Under this assumption, when you need to add more disk space to an existing database volume, you can't just add the disk(s) to the volume, as this would make the added space non striped, and would eventually create hotspots in the dataset. The correct approach in this situation is to create a number of new EBS disks enough to contain entire dataset plus the desired added space,so that you can grow the existing dataset while re-striping properly.
To make this clear, let's suppose you have a dataset volume of  3 TB,  made of 3 1TB EBS volumes which are striped across, but space is running …

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mylvmbackup 0.16 has been released

I'm happy to announce the release of mylvmbackup version 0.16. The source package is now available for download from http://lenzg.net/mylvmbackup/ and https://launchpad.net/mylvmbackup.

Installation packages for a number of platforms can be obtained from the openSUSE Build Service.

Version 0.16 adds support for sending out SNMP traps in case of backup successes or failures. I'd like to thank Alexandre Anriot for contributing this new feature and his patience with me.

Please see the ChangeLog and bzr …

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LVM read performance during snapshots

For the same customer I am exploring ZFS for backups, the twin server is using regular LVM and XFS. On this twin, I have setup mylvmbackup for a more conservative backup approach. I quickly found some odd behaviors, the backup was taking much longer than what I was expecting. It is not the first time I saw that, but here it was obvious. So I recorded some metrics, bi from vmstat and percent of cow space used from lvs during a backup. Cow space is the Copy On Write buffer used by LVM to record the modified pages like they were at the beginning of the snapshot. Upon reads, LVM must scan the list to verify that there’s no newer version. Here’s the other details about the backup:

  • Filesystem: 2TB, xfs
  • Snapsize: 60GB
  • Amount to backup: ~600GB
  • Backup tool: mylvmbackup
  • Compressor: pbzip2

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Log Buffer #282, A Carnival of the Vanities for DBAs

Blogging is the way to express an idea in an informal way by a person, who has either worked with it, or planning to work with it, or has seen it at work. In databases, ideas are the foundations of everything, and these Log Buffer Edition is presenting ideas from bloggers in Log Buffer #282. [...]

Linus on Instantiation and Armadaification

I feel a sense of pride when I think that I was involved in the development and maintenance of what was probably the first piece of software accepted into Debian which then had and still has direct up-stream support from Microsoft. The world is a better place for having Microsoft in it. The first operating system I ever ran on an 08086-based CPU was MS-DOS 2.x. I remember how thrilled I was when we got to see how my friend’s 80286 system ran BBS software that would cause a modem to dial a local system and display the application as if it were running on a local machine. Totally sweet.

When we were living at 6162 NE Middle in the nine-eight 292, we got an 80386 which ran Doom. Yeah, the original one, not the fancy new one with the double barrel shotgun, but it would probably run that one, too. It was also …

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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 a11y.com

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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Vote for MySQL[plus] awards 2011 !

First of all, I wish you a happy new year.
Many things happened last year, it was really exciting to be involved in the MySQL ecosystem.
I hope this enthusiasm will be increased this year, up to you !

To start the year, I propose the MySQL[plus] Awards 2011
It will only take 5 minutes to fill out these polls.
Answer with your heart first and then with your experience with some of these tools or services.

Polls will be closed January 31, so, vote now !
For “other” answers, please,  let me a comment with details.

Don’t hesitate to submit proposal for tools or services in the comments.
And, please, share these polls !

 

Note: There is a poll embedded within this post, …

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Join us at the OTN Sys Admin Day for Oracle Linux and Solaris on Sep. 22nd, Seattle (WA)

Last week we concluded our first Oracle Technology Network Sys Admin Day in Sacramento (CA). Well, it was actually the second Sys Admin Day, but the first one that had two parallel tracks of sessions about both Oracle Linux and Oracle Solaris.

I helped preparing for the event by creating the Linux lab handbook as well as the VirtualBox appliance of Oracle Linux 6.1 that was used for the exercises. Unfortunately I could not be there in person, but it would have been pointless for me to go on an intercontinental flight just for one day.

From the feedback we've received so far, the attendees really enjoyed the event and were positively surprised about the depth and quality of the practical hands-on lab sessions.

If you've missed the first one and happen to live …

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On LVM: How to setup Volume Groups and Logical Volumes.

LVM (Logical Volume Management) is a very important tool to have in the toolkit of a MySQL DBA. It allows you to create and extend logical volumes on the fly. This allows me to, say, add another disk and extend a partition effortlessly. The other very important feature is the ability to take snapshots, that you can then use for backups. All in all its a must have tool. Hence, this guide will allow you to understand various terminologies associated with LVM, together with setting up LVM volumes and in a later part will also show you how to extend...

451 CAOS Links 2011.05.03

Novell sold to Attachmate. Barnes & Noble throws the book at Microsoft. And more.

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca, and daily at Paper.li/caostheory
“Tracking the open source news wires, so you don’t have to.”

# Novell closed its acquisition by Attachmate and its patent sale to CPTN.

# Attachmate’s CEO discussed the company’s plans for SUSE Linux.

# Barnes & Noble …

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