Citrix NetScaler with SSD (first impression)
April 1, 2012
The Citrix NetScaler MPX 5500-7500 and 9500 appliance models now ship with Solid State Drives and says (good?)bye to the platter disk for these particulair models. This was anounced by Citrix back in februari this year: http://blogs.citrix.com/2012/02/09/citrix-netscaler-moves-to-solid-state-drives-for-future-mpx-5500-7500-and-9500-shipments/
Citrix has been using Solid State Drives in the MPX 17500/19500/21500 platforms for a longer time but they are only used for mounting the /flash volume. In the MPX 5500/7500/9500 the /flash volume is mounted on a CompactFlash Card. The (platter) Hard Disk Drive which is now being replaced by an SSD is used for the /var volume, this is where all the data and logs files are kept.
I now have a set of Citrix NetScaler MPX 5500 series which has been delivered with such Solid State Drives. The SSD in question is a Samsung 2.5” 128GB SSD (SATA3.0Gbps) which is known as a Samsung 470 series. This particulair SSD can perform sequential reads up to 250 MB/sec and sequential writes at 220 MB/sec. In comparison to the latest releases of Solid State Drives those numbers are not amazing. More information of the SSD : http://www.samsung.com/us/computer/memory-storage/MZ-5PA128/US-specs
As you can see on the Samsung website this is not a high-end SSD for servers but merely a Desktop drive with mediocre specifications.
Copying files to the appliance.
Granted, not a real good test of the performance of an SSD, but I’m doing some basic setup stuff on these newly delivered appliances. Copying large files to the Citrix NetScaler is somewhat faster then it used to be. In the below example I’m copying the latest firmware to the appliance which is about 165MB in size.
Upgrading the firmware.
Upgrading the appliance to a newer firmware build is somewhat faster then it was before.
Booting the appliance
I am under the impression the appliance boots faster then the platter disk version, it takes the SSD Citrix NetScaler roughly about 3 and a half minutes to boot. In the below boot video there is little to none configuration in the Citrix NetScaler. When I come across a platter version of the Citrix NetScaler MPX 5500 series I will post the video’s side-by-side for comparison.
Accessing the interface.
What I’d find pleasently noticable is that the normally sluggish Java interface is bit faster to respond. But offcourse it is still Java slow.
Time will tell if moving from from the (finally) stable platter disks to SSD was a good decision made by Citrix. The NetScaler MPX line is good when it comes to stability of the platter disks, with the older Citrix NetScaler (7000, etc) series we had a relatively large amount of disk failures. Citrix NetScaler MPX did not seem to have that problem anymore.
The (relatively small) performance gain of the SSD shows when booting the appliance or doing maintenance on the machine (updating firmware, booting, extracting, etc) but how often do you such a task? That’’s right, as least as possible. I for one prefer stability of the Citrix NetScaler over a minimalistic boot time gain.
Another thing that I’m thinking of is Wear leveling, there is really not much known about wear leveling of SSD’s over a longer period of time, they have not proven themselfs yet to withstand years of read/write production.
As far as I know there is no TRIM functionality within Citrix NetScaler or FreeBSD, so I wonder what the performance will be like 6 months down the road. NetScaler still uses an old FreeBSD version which does not have this functionality built-in.
Another very valid reason for moving to SSD is simply consuming less power and be more green. This Solid State Drive consumes 0.24 Watts when active and about 0.14 Watts in Idle state, so that’s not bad. Since the performance is not that much different from the platter disk version, I think this has been the primary reason for Citrix to move to SSD.
Again, I will post an update as soon as I have more info on this.