V440 mobo hardware mirroring performance - worth it?
We just ordered a bunch of V440s. I notice this box has a hardware RAID1 capability, but can only mirror one drive.
What's the performance of this hardware RAID1 vs SVM?
If we can only mirror one pair of disks, it's hardly worth the bother, since for the sake of consistency I'd rather just use SVM since all my other Solaris servers use it, unless there is an obvious performance advantage.
Also, my experiences with onboard hardware RAID have been historically, uhhh, cheesy. Although the raidctl command is probably hoing to remain supported for the life of the hardware, unlike OTHER vendor's onboard RAID.
Thanks in advance, this will save me a few hours doing benchmarks I am sure have been done already. Or if real world experience teaches us to stay away from the hardware RAID.
[821 byte] By [
wsanders] at [2007-11-26 11:19:16]
# 1
Short answer: Worth it, maybe, especially if you have only 2 internal drives.
Well, to answer my own question, here are the results of a "stupid"
mkfile test. Three options were tested: V440 HW RAID1, Single disk, and
SVM/Disksuite RAID1. Otherwise idle system
First test: Time to resync a 72G disk. SVM is much slower: 119 min for SVM vs 57
min for the hardware raid. Iostat results: 9.2 MBytes/sec IO for SVM,
? MBytes/sec for the HW RAID since the data is hidden from iostat once
the mirrored volume is created.
Second test: mkfile 2000m junk. All three options show the same
performance, wall clock time 33-34 sec and iostat 66-67 MBytes/sec,
which match.
I'm not a big fan of embedded RAID, and considering the difficulties
discussed in this thread:
http://forum.sun.com/jive/thread.jspa?threadID=100007&tstart=0
it's just not worth the risk to me, particularly since i have 4 internal
disks, so I have to use SVM anyway to mirror the other two (the controller
allows you to only mirror two of the disks on the bus), and not
having one disk "disappear" under embedded RAID control allows me to
have 4 copies of metadb's.
