I have seen extremes when it comes to this topic. I have a forum 1.2mil posts 60k users, about 15GB total site size. I have a dedicated server being configured and for now have gone with an SSD intel 320 120gb as primary disk. This is to try to manage my costs and get some decent performance. The host is large, reputable. Their operations manager replied to my concerns that he's never had a 320 ssd fail since they began using them some time ago. I will also have a non-ssd backup disk and be doing frequent backups. So.. I have heard people state SSD is no good for webhosting and I have heard people say "you definitely want to go with SSD". Is a lot of the negativity towards SSD still lingering from the old days. Are there any MAJOR concerns with Intel 320's? Should I instead be running 2 320's in raid1 to be safe? If data corrupts on one 320 how likely would it be to spill over onto the mirror disk and defeat the purpose anyway? I can always back out of SSD and fork over more cash for Raid 10 15k array. What do you guys think? Thanks
We recently provisioned a server with SSD (Intel 320) for the OS/MySQL and then a 8 disk RAID10 SAS array for /home. The problem with using all SSD setups for shared hosting is the cost. It's simply not cost-effective yet, particularly considering the price people are willing to pay for shared hosting. Your plan of backing up the SSD on a magnetic drive is just fine. Are you only using this for your forum, or for hosting, or...? If you're only using it for your forum (i.e. won't need massive amounts of disk space), a SSD RAID10 setup would do amazing things for your speed. The cost will probably be comparable to a 4-drive SAS setup, but with about half the disk space or less. Heck, as long as you're using a magnetic drive for backup, you might even want to run 2 SSD drives in RAID0 for speed.
No hosting, It's only for my forum, so just one site & DB on the server, will probably never occupy more than 20-25GB of the total 120GB. Just curious, is there a recommended type of backup system that can, in a way almost mirror my SSD to the backup drive? It would be appealing to lose a few minutes of data vs. 12hrs if the disk ever crashed. I also do rsync's to rsync.net and to my home system for good off-site backups. Rsync runs once a day, and i sync that to my home system once a week.
dd is the command to mirror a drive. dd if=/dev/sda of=/dev/sdb would clone your SDA disk to SDB, for example. Run it in reverse to restore the drive. It's not something you want to be doing frequently though, as it is going to take resources. Outside of RAID, there really isn't anything that is going to keep a rolling copy.
The issue with SSD's is mostly down to the fact that they are still relatively new and there was a lot of reports of failures when they were first released. Although they've been around for a while, it's only now that 2.5" drives are starting to become more commonplace in server installations. In the past, 2.5" disk were commonly seen as "laptop" drives, and things like spindle speeds and seek times on 2.5" SAS/SATA drives couldn't (still don't) quite match the performance characteristics of 3.5" drive, so that bias is still lingering a bit - it shouldn't impact on any bias towards/against SSD drives...but it does. We've just built our first servers with hardware raid controllers and SSD drives, and their performance is through the roof compared to anything we've built before, but I can't speak for their longevity yet. The only issue I can see with your set up is 1. A single SSD drive is a single point of failure. Get a couple (at least) and configure them in RAID1, or better if you have more drives. 2. The Intel320 is a SATAII connection i.e. 3Gbps. The Intel520s have a faster interface (6Gbps), and coupled with a RAID controller with similar connections, you'll get better performance. Whether you'll notice that increased performance wil depend on what you're doing.