Posts

Showing posts from October, 2013

Western Digital Green Drives and Linux - They're dying!

The last time I swapped the drives out in my home built NAS, I bought Western Digital Green drives.  They sounded great!  Low power, low heat, low noise... Unfortunately, they appear to not have been built for this particular application.  They auto park and the timer is set too low for Linux filesystems.  (I believe the default may be 8 seconds! http://techreport.com/forums/viewtopic.php?f=5&t=78891) My drives began to give me trouble (thankfully) even before the warranty ran out.  I found the load cycle count on my drive to be extremely high - 10's or 100's of thousands.  This is way beyond the expected count. Here's how to query for it: # smartctl -A /dev/sdX | grep ^193 193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       XXXXXXX Luckily there is a solution -- run this tool to either turn off the feature, or set the timeout much higher:     http://idle3-tools.sourceforge.net/ Make sure you follow the instructions cl

SATA errors on Linux with Samsung SSD 840 Series with Asus M2N-E

This problem had been driving me crazy for weeks.  I run a home linux server (currently Fedora Core 18) as a NAS and various other services.   Ever since I upgraded the OS disks to SSD I began getting SATA errors in my kernel logs: Jul 31 00:02:26 kernel: [20859.208310] ata3:EH in SWNCQ mode,QC:qc_active 0x7E sactive 0x7E Jul 31 00:02:26 kernel: [20859.208371] ata3: SWNCQ:qc_active 0x3E defer_bits 0x40 last_issue_tag 0x5 Jul 31 00:02:26 kernel: [20859.208482] ata3: ATA_REG 0x41 ERR_REG 0x84 Jul 31 00:02:26 kernel: [20859.208533] ata3: tag : dhfis dmafis sdbfis sactive Jul 31 00:02:26 kernel: [20859.208585] ata3: tag 0x1: 1 0 0 1 Jul 31 00:02:26 kernel: [20859.208636] ata3: tag 0x2: 1 0 0 1 Jul 31 00:02:26 kernel: [20859.208697] ata3: tag 0x3: 1 0 0 1 Jul 31 00:02:26 kernel: [20859.208748] ata3: tag 0x4: 1 0 0 1 Jul 31 00:02:26 kernel: [20859.208800] ata3: tag 0x5: 0 0 0 1 Jul 31 00:02:26 kernel: [20859.208860] ata3.00: exception Emask 0x1 SAct 0x7e SErr 0x0 action 0x6 frozen Jul 31

When to ask for help when stuck on a technical problem

I thought this blog post by  +Matthew Ringel was a concise and useful summary of how (and when) to ask for help when stuck on a technical problem: https://blogs.akamai.com/2013/10/you-must-try-and-then-you-must-ask.html I often find coworkers skipping step #1: working at the problem a little longer and documenting/recording/reviewing what you've already tried. When I do step #1 I often solve the problem myself.  I might be in the middle of an email explaining what the problem is.  I owe it to them to explain what I've tried, what results I got, etc.  Most of the time the solution then presents itself!  I then just delete the email draft and keep plugging away. But then sometimes I wait too long for step #3 - going and asking for help. And then sometimes, I just need a rubber duck: http://www.rubberduckdebugging.com/

Removing Embedded JPGs from Nikon NEF Files with Exiftool

I've been migrating away from Capture NX2 to Lightroom for editing my raw NEF's.  But I'm not quite ready to convert completely from NEF to DNG (Digital Negatives.)  I still might want to edit the photo in Capture - the control points are just too useful.  One tempting advantage of DNG is that they are reportedly a little smaller than NEF. Why are the DNGs smaller?  I believe it is due to the NEF's embedded jpgs.  But Lightroom doesn't really need the jpeg rendering that is stored in the NEF and I could always recreate them later.  So how can I drop them? Exiftool! +Jeffrey Friedl 's blog post at http://regex.info/blog/2006-12-08/303 put me on the right track, but I think his information is out of date now.  I found that my NEF had three jpgs: JpgFromRaw (Full Size!) OtherImage (Fairly large!) PreviewImage (Thumbnail-ish) Let's see how big the are in an NEF that is 44133771 bytes: $ exiftool -list D8H_2754_20131001_183719.NEF  | egrep Binary\