We have a ReadyNAS 4200 configured in RAID 0. It's directly connected via 10gig ethernet to a Linux 2.6 machine (no switch or hub). What sort of sustained write speed should we be able to get?
Side note: The business products support line (1-855-776-7233) is broken.
Kevitivity, From my view it could be difficult to get a write speed figure in a RAID 0 situation, as most customers use X-RAID, with data striping across disks.
I'm in Tech support and am not aware of the phone # below being down. I 've been getting USA calls this week.
More information would be needed to be able to give much of an indication as to numbers you are able to achieve are reasonable.
What are the specs of the PC? What disks do you have installed in each machine? What RAID configuration is in use in the PC?
You should be able to get hundreds of MB/s.
Whilst with RAID-0 may give you higher performance than using X-RAID2, it is not recommended. If one disk fails all the data on the RAID-0 volume is lost.
Of course the hundreds of MB/s speed assumes sequential writes to large files. Small file writes/database updates wold be much less due to seek time.
For instance, a 3 TB Seagate Barracuda spinning at 7200 RPM has a large-file throughput ranging from ~93 MB/s to ~193 MB/s depending on where on the platters you are actually writing. But its 4K random write performance is ~160 writes per second, which turns into ~640 KB/s. Fast random writes require SSDs. (http://www.tomshardware.com/reviews/4tb ... 83-12.html)
RAID-0 striping should disperse the writes evenly across the disks, so theoretically an array of 4x3 TB would have 4x the performance. In practice you might run into other bottlenecks of course.
But the striping also makes RAID-0 fragile, so it is particularly important to maintain good backups if you are needing that mode for performance reasons. As mdgm points out, any failure will destroy the entire array.
Right, we don't care about data integrity for this scenario, we're ONLY concerned with figuring out what sort of sustained write speed this setup (twelve 2TB drives in RAID 0) is capable of. Because there isn't any documentation on it, we don't know what to expect. We're using a simple C program to blast random data to the NAS in 32mb chunks. Admittedly, we may be going about our tests all wrong, but it would be nice to know what this NAS should be capable of.
We also find it odd that the max MTU on the 10gb interface is only 1500. Is there any way around this limit?
Drives are 2T Hitachi HUA722020ALA330 enterprise (7200rpm)
The PC is a server class box, 24GB RAM, 10k RPM SAS drive with a single 8-core Xeon (E5607) @ 2.27GHz. One user.
