Posts tagged SSD
I’m not entirely sure how long ago I started using dedicated servers (only one for the first few years though) for my sites, but it must be around 10 years or more. My account on WHT.com is over 10 years old, and in the oldest posts there suggest I had a Cobalt RAQ at the time, while I’m pretty sure that wasn’t the first dedicated server I ever used.
The advantage and disadvantage of dedicated servers is that you’re just renting the hardware. On the one hand this means your host is responsible for any hardware trouble, which can be quite convenient at times. On the other hand, if you need really powerful hardware (high-end CPU, lots of RAM, fast RAID) you’re paying a hefty sum each month for that hardware.
The advantage of colocation is that you can bring your own hardware and the price will typically remain the same (though you might pay more for power usage and rack space for really big and powerful servers). The downside of course is that if anything goes wrong (beyond the scope of “remote hands” from the datacenter at least) you’re responsible for it, which might mean a trip to the datacenter (which will take time, and it may be hard getting replacement parts in the middle of the night or in weekends).
For my first colocated server I’ve settled for a Supermicro 510T-200B case with Supermicro X9SCL-F motherboard as base. For CPU I picked the Intel G620T which is a Sandy Bridge dual-core CPU with roughly the same power as Core2Duo E8400, but with only a 35W TDP. For RAM I just picked cheap 8 GB Kingston ValueRAM and the hard-drives are a cheap OCZ Vertex 2 60 GB SSD for OS and simple 2.5″ 320 GB SATA drive for backups.
The result is a quite small and low-power server which should be fast enough for most purposes. Having said that, the case was a bit tight so next time I’ll probably spend a little more on the case and get a Supermicro 813MT-350CB instead, which also has space for four normal 3.5″ drives and uses rails instead of cage nuts.
The server is colocated (as of Wednesday August 24) at Serverius, who had a very good deal on WHT: 1U, 25TB and 1 ampere power (my server will use only about 25% of that) for 39 euro per month (excl. VAT). They are clearly overselling on bandwidth with this deal, but I don’t mind as I don’t really need that much anyway.
Now for the embarrassing part: when I showed up I seemed I had forgotten to take with me just about everything except the server itself. Serverius normally requires customers to bring their own power cable, CAT cable and cage nuts (for which you also need a screwdriver) and I didn’t bring any of that. Well I did bring a power cable, but the wrong one: the required the extension cable kind, not power cables with a normal plug.
But fortunately they were courteous enough to lend me all that. And while they seem very boringly simple cage nuts are actually quite expensive, which has to do with the requirements they have to operate at or something. Anyway I just have to remember to bring my own (to replace what I borrowed) next time 🙂
Although the spot they allocated me in the rack was quite hard to get to (near the top of the rack, just below their speedtest server) I was able to install the server without to much trouble. The real problem was getting IPMI to work. But for more on that, see my next post.
At this time I’ll see how things go for a few weeks and if everything goes as well as I hope it will, I’ll probably start colocating most of my servers, possibly even in a private half rack. The only ones I might keep renting are those that need loads of bandwidth, as it is still simply cheaper to rent those at providers who oversell their bandwidth (or otherwise can get better bandwidth deals than that would be possible with colocation).
Modern SSDs support the TRIM command for long-term sustained performance. However for TRIM to work right, the OS (and file system) must have support for it. In the case of Linux, you’ll need kernel version 2.6.33 or newer, use ext4 as file system and also tell the kernel to use TRIM using the “discard” mount option.
By default the Debian installer tends to prefer ext3, so be sure to change this to ext4 on a fresh install. If you have already installed Debian on a SSD with ext3, you will need to convert it to ext4 – I will not cover this here.
Debian 6.0 includes kernel version 2.6.32 by default. To use a newer kernel you do not need to turn to the testing or even unstable (Wheezy) distributions; just enable the (official) Squeeze Backports by adding this line to /etc/apt/sources.list
deb http://backports.debian.org/debian-backports squeeze-backports main contrib non-free
Then run aptitude update to get the new package list. To upgrade to the latest kernel included with the backports that does support TRIM (2.6.39 at the time of writing) run:
aptitude install -t squeeze-backports linux-image-2.6-amd64
(change amd64 to i386 if you’re still running the 32-bit version of Debian)
To enable TRIM support then add the “discard” mount option to /etc/fstab: change the default “errors=remount-ro” into “errors=remount-ro,discard”. Reboot and you’re done.
Note! Do not add the “discard” option when your drive is formatted as ext3: not only will it not work, but it will prevent the OS from booting properly.