Frozen Industries

failed hard drives

Nick — Wed, 27 Apr 2011 05:17:17 +0000

Keeping track of my drive failures, since April 2011.

Age (Months)	Purchased	Died	Model
18	2010-04	2011-10	1.5 TB Western Digital Green 64MB Cache 5400RPM
15	2010-04	2011-07	1.5 TB Western Digital Green 64MB Cache 5400RPM
26	2009-02	2011-04	1 TB Hitachi Deskstar 7K1000.B 16MB Cache 7200RPM

parted

Nick — Tue, 26 Apr 2011 03:55:02 +0000

Create a single, aligned partition on a drive larger than 2TB.

% sudo parted /dev/sdx
(parted)% mklabel gpt
(parted)% mkpart primary 1 -1

New HTPC

Nick — Mon, 31 Jan 2011 07:17:47 +0000

Just replaced my heavily used Ubuntu HTPC with a 6 watt AppleTV 2. Both run XBMC.

Specs of the old, silent HTPC:

Intel Core 2 Duo E4300 1.8GHz w/2MB Cache
Intel DQ965GF motherboard with passive chipset heatsinks
Scythe Ninja passive CPU heatsink
4GB (2x 2GB DIMMS) ADATA DDRII 800 MHz memory
512 MB MSI N210-MD512H GeForce 210 PCIe 2.0 passive video card
40 GB Kingston SSDNOW V-series (Intel rebranded) SATA SSD
18x DL DVD+-RW Optiarc Ad-7170S 2MB Cache SATA optical drive
Antec Sonata case
Dual 120mm Yate Loon case fans
Seasonic 330W power supply
Ubuntu 10.04 AMD64 with XBMC

Video is just as smooth on the AppleTV as on the HTPC.

15,471,232 Pixels

Nick — Sat, 13 Nov 2010 20:04:53 +0000

Screens I look at on a normal weekday:

iPhone 4 (3.5″) (960 x 640)
iPad (9.7″) (1024 x 768)
Netbook (10.1″) (1024 x 600)
Work MacBook (15.4″) (1440 x 900)
Work Desktop (27″ + 24″) (2560 x 1440 + 1920 x 1200)
Home Desktop (30″) (2560 x 1600)
HTPC (42″) (1920 x 1080)

Linux Software RAID10 Benchmarks

Nick — Sun, 31 Jan 2010 21:55:34 +0000

Tests are done across four 7200RPM SATAII drives on a PCI-X card sitting on a PCI (32-bit, 133MB/sec theoretical max) bus, probably the slowest bus configuration possible, and then again after being moved to a motherboard with dual PCI-X slots. Server is running Ubuntu 9.10 AMD64 Server.

Benchmark is a simple ‘dd’ sequential read and write.

write: dd if=/dev/zero of=/dev/md2 bs=1M
read: dd if=/dev/md2 of=/dev/null bs=1M

mdadm –create /dev/md2 –verbose –level=10 –layout=n2 –raid-devices=4 /dev/sd[ftlm]1

	PCI	PCI-X
write:	13.2 MB/s	144 MB/s
read:	4.0 MB/s	89.3 MB/s

mdadm –create /dev/md2 –verbose –level=10 –layout=f2 –raid-devices=4 /dev/sd[ftlm]1

	PCI	PCI-X
write:	48.3 MB/s	131 MB/s
read:	92.7 MB/s	138 MB/s

mdadm –create /dev/md2 –verbose –level=10 –layout=o2 –raid-devices=4 /dev/sd[ftlm]1

	PCI	PCI-X
write:	47.4 MB/s	135 MB/s
read:	98.7 MB/s	142 MB/s

And more comparisons:

RAID1 (PCI)

write: 38.9 MB/s
read: 64.8 MB/s

Single Disk (PCI)

write: 59.4 MB/s
read: 71.9 MB/s

Remove Stale LVM Devices

Nick — Sun, 24 Jan 2010 06:47:04 +0000

Have an LVM device left on your system from a drive that was removed before pvremove was run?

1	$ sudo dmsetup remove /dev/mapper/removed-device

My Tivo Twitters

Nick — Wed, 23 Sep 2009 05:54:28 +0000

I wrote a short script that sends a Tweet whenver my Tivo HD starts recording a show. You can download it below. It runs best on a Linux computer that can constantly poll the Tivo.

Download: tivo_twitter.sh script

Results: http://twitter.com/30west

365 Days of Uptime on a Linksys router

Nick — Thu, 09 Jul 2009 02:49:13 +0000

I passed 365 days of uptime on my Linksys WRT54GL v1.1 router. It’s running DD-WRT firmware, and sits on a large APC UPS. Total data transfer on the router’s WAN port is reported at 1,570,619 MB down/ 79,832 MB up.

Replace an LVM Drive with a Larger One

Nick — Sun, 22 Mar 2009 06:56:19 +0000

LVM allows you to hot add devices to expand volume space. It also allows you to hot remove devices, as long as there are enough free extents in the volume group (vgdisplay) to move data around. Here I’m going to replace a 400 GB drive (sdg) with a 750 GB one (sdf) from logical volume “backup” on volume group “disks”. It does not matter how many hard drives are in the volume group, and the filesystem can stay mounted.

Partition and create a physical volume on the device
1
$ sudo pvcreate /dev/sdh1
Add the new drive to the volume group
1
$ sudo vgextend disks /dev/sdh1
Move all extents from the old drive to the new one (this step may take hours)
1
$ sudo pvmove -v /dev/sdg1
Remove the old drive
1
$ sudo vgreduce disks /dev/sdg1
Expand the logical volume to use the rest of the disk. In this case, another 350GB.
1
$ sudo lvextend -l+83463 /dev/disks/backup
Expand the file system
1
$ sudo resize2fs /dev/disks/backup

mdadm Cheatsheet

Nick — Tue, 04 Nov 2008 18:49:15 +0000

Scan a system for RAID arrays and save findings so the array reappears across reboots:

1	# mdadm --detail --scan >> /etc/mdadm/mdadm.conf

Create a RAID5 array out of sdm1, sdj1, and a missing disk (all partitioned with raid-autodetect partitions)

1	# mdadm --create /dev/md1 --level=5 --raid-devices=3 /dev/sd[mj]1 missing

Create a RAID1 array

1	# mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sd[ts]1

Remove a RAID array

1 2	# mdadm --stop /dev/md1 # mdadm --zero-superblock /dev/sd[ts]1

Replace a failed drive that has been removed from the system

1	# mdadm /dev/md3 --add /dev/sdc1 --remove detached