[CentOS] ssd quandry
John R Pierce
pierce at hogranch.com
Tue Oct 25 09:47:54 UTC 2011
On 10/25/11 2:16 AM, John Doe wrote:
> Just wondering how come the array is detected as /dev/sd* instead of the classical /dev/cciss/c0d*...
> Is the P411 a fake raid?
no, its a seriously fast pci-e SAS2 hardware raid. the physical
devices don't show at all. it has 1GB of writeback cache thats backed
by flash with a supercap, instead of the traditional battery that dies
in 3 years.
I didn't have to install any special drivers to use it, C6 just saw it
as-is, /dev/sda is a raid1 of disks 0,1, /dev/sdb is a raid10 of disks
2-22, and sdc is a raid0 of SSD 23,24 (disk 25 is a hot spare for sda,sdb)
its configurable with the hpacucli command tool I got from HP's site.
# lspci -vnn -s 6:0.0
06:00.0 RAID bus controller [0104]: Hewlett-Packard Company Smart Array
G6 controllers [103c:323a] (rev 01)
Subsystem: Hewlett-Packard Company Smart Array P410 [103c:3243]
Flags: bus master, fast devsel, latency 0, IRQ 24
Memory at fbc00000 (64-bit, non-prefetchable) [size=2M]
Memory at fbbff000 (64-bit, non-prefetchable) [size=4K]
I/O ports at d800 [size=256]
Expansion ROM at fbb00000 [disabled] [size=512K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Endpoint, MSI 00
Capabilities: [ac] MSI-X: Enable+ Count=16 Masked-
Capabilities: [100] Advanced Error Reporting
Kernel driver in use: hpsa
Kernel modules: hpsa
# hpacucli ctrl slot=1 show detail
Smart Array P410 in Slot 1
Bus Interface: PCI
Slot: 1
Serial Number: PACCRCN810E1R9J
Cache Serial Number: PBCDF0CRH0Q13H
RAID 6 (ADG) Status: Disabled
Controller Status: OK
Hardware Revision: Rev C
Firmware Version: 5.12
Rebuild Priority: Medium
Expand Priority: Medium
Surface Scan Delay: 15 secs
Surface Scan Mode: Idle
Queue Depth: Automatic
Monitor and Performance Delay: 60 min
Elevator Sort: Enabled
Degraded Performance Optimization: Disabled
Inconsistency Repair Policy: Disabled
Wait for Cache Room: Disabled
Surface Analysis Inconsistency Notification: Disabled
Post Prompt Timeout: 0 secs
Cache Board Present: True
Cache Status: OK
Accelerator Ratio: 25% Read / 75% Write
Drive Write Cache: Disabled
Total Cache Size: 1024 MB
No-Battery Write Cache: Disabled
Cache Backup Power Source: Capacitors
Battery/Capacitor Count: 1
Battery/Capacitor Status: OK
SATA NCQ Supported: True
dunno if that helps?
since I got it sorted out with 4k blocks and XFS, I'm seeing about 12000
write IOPS via pgbench to that sdb raid10, and 16000 wr/s to the sdc SSD
raid1, these are both pretty close to flat out for the disks. sustained
writes from iozone hit 1.2GB/sec on sdb and 800MB/s on sdc, also pretty
much hardware bandwidth of the disks.
--
john r pierce N 37, W 122
santa cruz ca mid-left coast
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