Disk speed

Being a virtual machine on a shared server I wasn't expecting too much disk performance from my linode. I was amazed by just how fast disk access was.

On a dedicated server from Hetzner:

hdparm -t /dev/sda

/dev/sda:

Timing buffered disk reads: 194 MB in 3.02 seconds = 64.18 MB/sec

On my laptop with a OCZ 64 SSD:

hdparm -t /dev/sda

/dev/sda:

Timing buffered disk reads: 216 MB in 3.00 seconds = 72.00 MB/sec

On a linode 512:

hdparm -t /dev/xvdc

/dev/xvdc:

Timing buffered disk reads: 544 MB in 3.00 seconds = 181.20 MB/sec

What I would like to know is what kind of storage are Linode using? High end SSD's? A fiber SAN from EMC or Hitachi? Ram disks?

4 Replies

Hmmm. I get anywhere from 95 to 120 MB/sec on my Linodes.

My understanding is that Linode uses 15k disks in RAID 1+0. Not sure if they're SCSI or SAS.

I ran it three times one after another, amazing numbers indeed:

Timing buffered disk reads: 574 MB in 3.00 seconds = 191.04 MB/sec

Timing buffered disk reads: 418 MB in 3.01 seconds = 139.02 MB/sec

Timing buffered disk reads: 434 MB in 3.03 seconds = 143.22 MB/sec

I've been checking my Linode 360/512 off and on, and while performance varies, it's always been better than my old low-end dedicated server I had before Linode, when I've checked.

Old dedicated server with two 7200 rpm SATA drives (RAID 1):

Timing buffered disk reads: 222 MB in 3.02 seconds = 73.53 MB/sec

Linode:

(After Setup): Timing buffered disk reads: 250 MB in 3.04 seconds = 82.20 MB/sec

(5/21/2010): Timing buffered disk reads: 464 MB in 3.00 seconds = 154.44 MB/sec

(5/22/2010): Timing buffered disk reads: 554 MB in 3.02 seconds = 183.54 MB/sec

(5/23/2010): Timing buffered disk reads: 538 MB in 3.01 seconds = 179.02 MB/sec

(5/24/2010): Timing buffered disk reads: 318 MB in 3.00 seconds = 105.85 MB/sec

(6/17/2010): Timing buffered disk reads: 568 MB in 3.01 seconds = 188.86 MB/sec

(7/18/2010): Timing buffered disk reads: 602 MB in 3.00 seconds = 200.60 MB/sec

I recently moved to Linode from a Eurpoean "cloud" service. The I/O was on average 30 MB/s. At one point, I was on a filer that reported buffered reads in kB/s. Much of the rest hovered around single digits in MB/s. My Linode is between 160 and just over 200 MB/s. While the idea, and it never seemed to work in practice, of the "cloud" is that the network layer and disks will keep a constant I/O (never any "bad" neighbors), I think I can tolerate some wider fluctuations, measured in MB/s, when the low is 5 times better.

Reply

Please enter an answer
Tips:

You can mention users to notify them: @username

You can use Markdown to format your question. For more examples see the Markdown Cheatsheet.

> I’m a blockquote.

I’m a blockquote.

[I'm a link] (https://www.google.com)

I'm a link

**I am bold** I am bold

*I am italicized* I am italicized

Community Code of Conduct