Tonight I was reading about ZFS and ZIL devices. I clarified a few things in my mind. ZIL versus SLOG ZFS uses a ZIL (ZFS Intent Log). This can be on the same device as the zpool. If the ZIL is on another device, that device is known as a SLOG (Separate Log). Thus, the ZIL is on the SLOG. It can be very beneficial if the SLOG is a much faster device […]
ZIL mirroring no longer vital Read More »
Following on from yesterday’s benchmark, I’m adding in some ZFS tests. All hardware is the same. Of note: $ zdb | grep ashift ashift: 9 $ sudo diskinfo -v ada0 Password: ada0 512 # sectorsize 128035676160 # mediasize in bytes (119G) 250069680 # mediasize in sectors 0 # stripesize 0 # stripeoffset 248085 # Cylinders according to firmware. 16 # Heads according to firmware. 63 # Sectors according to firmware. S12PNEACB31368P # Disk
Benchmarking the Samsung SSD 840 PRO Series DXM03B0Q – ZFS Read More »
GEOM Watch sent me an email this morning: The status of GEOM MIRROR/gm0 has changed from COMPLETE to DEGRADED. The following components have been lost: ad6 Remaining components: ad3 Here’s the smartctl output: [dan@ngaio:~] $ sudo smartctl -a -i /dev/ad6 smartctl 5.43 2012-06-30 r3573 [FreeBSD 8.2-STABLE i386] (local build) Copyright (C) 2002-12 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Model Family: Maxtor DiamondMax Plus 9 Device Model: Maxtor 6Y120M0 Serial
MIRROR/gm0 has changed from COMPLETE to DEGRADED Read More »
In this post, we’re going to demonstrate why aligning your disk partitions can be a good idea. For starters, we’re going to go with the default alignment, do a test, then align, and redo the test. But first, in case you have no idea what I’m talking about, this randomly discovered post may be a useful primer. Create the scheme on the disk This command creates a GPT scheme on the drive. Create
Aligned versus not aligned Read More »
During a recent install of FreeBSD 9.1 onto a gmirror, it was pointed out that my disk partitions were not aligned. Today, I’ll look at how that affects performance, both before and after alignment. Last night, I installed FreeBSD 9.1 onto a separate HDD, which I’ll use as a floater. I can attach this HDD to any system I need to work on without booting from the main HDD. In attached this HDD
Aligning disk partitions for better throughput Read More »
Late last week I installed FreeBSD 9.1 onto a gmirror, which I created during the install process. I documented it via photographs and comments. Hopefully, the next time I do this, it will be useful to refer to this resource. NOTE that when I did this, the partitions were not aligned properly. See the comments in the above URL for details. I will be covering this in a future post.
Installing FreeBSD 9.1 into a gmirror Read More »
People often talk about security. There are many different types of security. Personal security. Security theater. Physical security. In this post, we’ll talk about securing communications channels so that others cannot listen in, and so that others cannot connect. In this article, I’ll talk about using a toolkit, ssl-admin, to create a certificate authority, create self-signed certificates, and use them for both backups (via Bacula) and for a VPN (using OpenVPN). We will
I wrote this some time ago, but never published it. Here we go… Bacula is a fantastic backup solution. It’s open source. It uses a database to keep track of backups. I’ve been writing recently about using ssl-admin as a certificate authority tool. Today, I started using ssl-admin for generating certificates for my backup clients. In this post, I’m using Bacula 5.2.12 and using this reference page as a guide. I started playing
Bacula: TLS Allowed CN Read More »
I found this special idea about banning spammers: echo “select comment_author_IP from wp_comments where comment_approved = ‘spam'” | \ mysql –skip-column-names -u root wordpress_danlangilleorg | \ xargs -n 1 -J % sudo pfctl -t idiots -T add % Anyone care to explain how this works?
The PGCon 2013 Call for papers is out. It’s been out for over two weeks. Had you heard about it already? If you have not already submitted, please do so. The deadline for submissions (19 Jan) is just over a month away. That time will fly past. Please don’t leave it to the last minute. If you are doing something interesting with PostgreSQL, please submit a proposal. You might be one of the
PGCon 2013 call for papers Read More »