Disk on sigtar.com

HEVC media optimization

Tue, 30 Jun 2020 00:00:00 +1200

Do you have a large collection of video media files not using HEVC (H265) yet? There is a massive amount of disk space coming your way if you flick over to the new video codec format.

HEVC definitely lives up to its name, for most media you can expect a 70% or more disk savings from transcoding from an old codec. There are some catches though… If you want your TV to play it direct (i.e. straight off the file) the codec will need to be supported by it. You can of course get around this by using a media server such as Plex or Emby which will transcode from HEVC back to a compatible format.

unraid smart check - dead WD green drive

Thu, 30 Oct 2014 00:00:00 +1300

errors on unraid GUI - sometimes its a loose cable, sometimes its an issue with the drive.

Run this command to check smart status

smartctl -a -d ata /dev/sda or if you are using a newer SATA controller smartctl -a -A /dev/sda

http://lime-technology.com/wiki/index.php/Troubleshooting

unfortunately in my case, looks like drive is pretty much dead… not too bad for a drive almost 5 years old.

its pretty typical of a WD green drive in its default config to die in this type of environment, no plans to replace it with a similar type drive. You can see below the incredibly high LCC count which indicates the drive header has parked this many times over its life. This is probably part of the problem - there is a tool you can run (check this vid, link for WDIDDLE3 also in comments - http://www.youtube.com/watch?v=J2eYyRI_F98) which disables the intellipark feature of the green drive. I never disabled the park timeout before this drive died (which defaults to 8 seconds!) – note: i have disabled it completely on my other green drives.

vmware : IDE to SCSI

Wed, 27 Apr 2011 00:00:00 +1200

I’ve found that vmware converter (this may be fixed in newer verions) creates vmware guests with an IDE controller. There can be performance issues if you choose to remain with this particular controller… Best bet is to change it to one of the various vmware SCSI controllers…

Depending on which windows operating system you are running depends on which controller you use…. http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006621

Guest Operating System	Adapter Type
Windows 2003, 2008, Vista	lsilogic
Windows NT, 2000, XP	buslogic
Linux	lsilogic

vmware - measuring iscsi write performance

Fri, 07 May 2010 00:00:00 +1200

I picked this trick up off vmware support. If you’ve got your iscsi all setup you can drop to the shell (either ssh or console) and do this to measure your average write throughput.

time vmkfstools -c 10G /vmfs/volumes/san_vmfs/my_vm/fat_disk.vmdk -d eagerzeroedthick

Try larger a larger disk if this is too quick (free space permitting)

Essentially this will initiate the host to create a fat disk in the location above. You will then get a time recorded on how long it takes to execute this command. Then you can use your maths skill to work out the transfer rate…

zfs - checking your zpool throughput

Wed, 18 Feb 2009 00:00:00 +1300

This is quite a good diagnostic for checking your disk throughput. Try copying data to and from your zpool while your running this command on the host…

zpool iostat -v unprotected 2

capacity     operations    bandwidth
pool         used  avail   read  write   read  write
----------  -----  -----  -----  -----  -----  -----
unprotected  1.39T   668G     18      7  1.35M   161K
c7d0       696G   403M      1      2  55.1K  21.3K
c9d0       584G   112G      8      2   631K  69.3K
c7d1       141G   555G      8      2   697K  70.0K
----------  -----  -----  -----  -----  -----  -----

The above command will keep displaying the above output every 2 seconds (average during that time). I’ve used it a few times to ensure that all disks are being used (in write operations) where needed. Of course read op’s may not be typically across all disks as it will depend where the data is…