[long] HELP! HP ML 350 G5 storage server _very_slow_ performances

[Matteo Emanuele]

Hi to anyone,
I have bought a proliant ML 350 G5 storage server with 2x250 GB RAID 1 disks on a smartArray E200i (64Mb onboard).
I'm experiencing terrifying performance leaks on SAS disks. I've tried every flavor of *nux except RHE, i386/AMD_64 distros and I've installed all the software required (hp-OpenPMI, hpasm,hprsm,cmanic,hpsmh and so on) without any problem. There are no kernel errors, the hardware is ok, HP Italy said that they could not do anything for such issues.
On a _clean_ installation (currently I'm using a SUSE enterprise) the avarage write speed is near 10 Mb/sec. When the server start executing programs which requires a lot of write accesses to the disk the system will slow down then hang. A 'sync' will take minutes to complete and the console login will timeout without being able to insert the password as requested.
Can anyone help me?
Regards,
Matteo

[TarunJain · Accepted solution]

Hi Matteo,
To improve the performance of ur system, The Controller cache memory can be upgraded to the maximum available & also make sure the HDD & Controller are also updated.
By doing this I have fixed performance issue with ML350G5 normal server.
But for maximum performance, we used P400 controller with 512MB BBWC & change the Read/Write cache ratio to 25:75.

May be that info would help u out.
TarunJain

[Matteo Emanuele]

Thanks!
I thought to buy a memory expansion for the controller but I thought that it could have been pointless with starting performance of the disks so poor! So I believed to have troubles in my installation.
How can HP sell a _storage_ server which such writing performance? The benchmark suite on the virtual machine (a windows 2000 on vmware) reports a write speed of 6Mb which is highly insufficient for the company purposes.
Sincerely I would have liked to know this in advance!
Thanks again and regards

Matteo

[Pieter 't Hart]

>>> The benchmark suite on the virtual machine (a windows 2000 on vmware)

????
are you sure you use the configuration as HP intended this?
from specs : Preconfigured hardware: Operating System drives and RAID preconfigured for out of the box "plug and play" installation

First step i would suggest is to eliminate the virtualisation layer and use w2k3 directly! then do the benchmarks.

[Matteo Emanuele]

I've tried with win2003. The benchmark scored less than 20 mb/sec, and this is the best result obtained with file chunks of 1 Mb. But I've bought this server because Linux is fully supported - and this is the truth. The problem is, IMHO, that the controller cache is 100% balanced for reading. But to change the value to 70/30 (for example) I've to upgrade the controller memory or possibly buy a new one.
For sake of clarity, outside the VM the writing performances are a little better, but still slower than the single disk in my home pc.
Thanks anyway!

[Pieter 't Hart]

try breaking the raid-config (back to jbod)

raid-1 means two controller write-operations for every I/O from the OS.
When there is too little cache this gives a performance drop when writing, instead of a performance gain when reading because two disks can service different i/o requests.

Pieter

[Matteo Emanuele]

Thanks, I will try asap! If you are right (and I think so) the performance will rise to match the standard for those disks. I will be probably forced to expand the memory of the SAS controller because I need mirroring but at least I will know why...
It seems odd to me that the old PIII server that this proliant should substitute, with an Adaptec ATA RAID 1200A controller (software emulation, no cache) had none of the above problems. And it's at least 3 times faster.
Regards

[Venilton Junior]

Mateo, just change your Cache ratio to 70 WR and 30 RW.

But, who sold a storage server to you to run an application? Storages servers are used for file serving, NAS, backup managers and also SAN.

There are several solutions to you. U can keep this config, RAID1 with yours 250GB SAS disks. Or increase your cache memmory, or buy two more disks to your server and expand your array to four disks and extend your logical volume to RAID1+0. Yes the controller can do it online.

With more disks working together, you can have greater throughput. That's the concept of JBODs, Storages in the SAN or we can say that's the concept of RAID.



Regards

[Matteo Emanuele]

Hi, I'm going to expand the cache of the controller to change the ratio. The application the server will run is neither CPU intensive nor time critical... I'm only interested to run a program in C which checks for the correctness of few thousands files and then stores them. The old PIII usually accomplished this tasks in few minutes, the ML350 hangs before finishing. I must admit that the machine is oversized for this purposes so I wouldn't ever imagined this situation!

[Matteo Emanuele]

Hi, I'm going to expand the cache of the controller to change the ratio. The application the server will run is neither CPU intensive nor time critical... I'm only interested to run a program in C which checks for the correctness of few thousands files and then stores them. The old PIII usually accomplished this tasks in few minutes, the ML350 hangs before finishing. I must admit that the machine is oversized for this purposes so I wouldn't ever imagined this situation!
Regards