topic Re: Array configuration in Disk Enclosures

Array configuration

Jack_126 — Wed, 27 Oct 2004 06:42:59 GMT

Dear All,

I have VA7110 array, having 10No. of 73gb HDDs. I can configure it in AUTO RAID or in RAID5 also.
1> Could u please suggest which one is best if I look for the performance.
2> If I look for performance and redundency.

Re: Array configuration

Ranjith_5 — Wed, 27 Oct 2004 06:51:40 GMT

Configure it in Autoraid mode.
Will be best for u.

regards,
Syam

Re: Array configuration

D Block 2 — Wed, 27 Oct 2004 06:56:22 GMT

jack,

AUTO-RAID is nice but there will be some future micro-code upgrades for this VA7110 device.. just to tweak and improve the AUTO-RAID smarts over time.

I would say, go with the more stable: RAID-5, you are in the control using this method regarding performance. see the doc link below from our forums:

a nice link about RAID levels.
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=681917

Re: Array configuration

Ranjith_5 — Wed, 27 Oct 2004 07:50:23 GMT

Hi jack,

The decisions and strategies involved in configuring an AutoRAID disk array are far less complex than those involved in configuring conventional RAID products. AutoRAID relieves you of many of the decisions regarding RAID levels and data location. AutoRAID automatically manages your data for you, providing redundancy and high performance with minimal involvement.

The primary decision in configuring an AutoRAID disk array involves balancing lower cost-per-megabyte of storage against the reduced cost of managing for future growth. Once you have made this decision, the rest is easy--just assemble the disk array hardware, install your applications, and let AutoRAID manage your data.

Regards,
Syam

Re: Array configuration

Jack_126 — Wed, 27 Oct 2004 10:09:41 GMT

Hi,
In AUTO RAID configuration it gives the Half of the capacity of total capacity.

I want to use RAID5 so that I can get max space. But I think there is only two option AUTO RAID and RAID 1+0.

So if any one who have worked on VA7110, can give idea to configure in RAID5 for getting the max. capacity.

Re: Array configuration

Uwe Zessin — Wed, 27 Oct 2004 10:51:51 GMT

I don't think you can do RAID-5 on the VA7110. Last time I checked it was RAID0+1 or AutoRAID, which is a mix of RAID0+1 and RIAD5DP - the storage array decides which data is stored in which RAID level.

Re: Array configuration

Jack_126 — Wed, 27 Oct 2004 11:18:10 GMT

Dear all ,

If any other expert can confirm that yes it can not be used as RAID5,dont think that I am not beliveing you but I have to confirm it to my IT Manager, that it can be used for either AUTO RAID or RAID 1+0 and in both ways we will get half of the space.

waiting for reply ASAP.

Re: Array configuration

Ranjith_5 — Wed, 27 Oct 2004 14:26:49 GMT

Hi Jack,

There are only 2 options. That is confirmed.
1.) Raid 0+1
2.) AutoRaid

There is no traditional RAID5 configuration option available on Storageworks Commandview SDM. You can make it clear this with you manager.

According to me better option will be Autoraid and I have configured the same here at my setup with VA7400.

When configured in the AutoRAID mode, the Virtual Array uses a combination of RAID 1+0 and RAID 5DP. As a result, the disks within a single RG can have a portion of its data capacity used as RAID 1+0, while the other portion is used as RAID 5DP. During disk failures, rebuild is directed to rebuild the most statistically vulnerable data first. After the first disk failure in an RG, the rebuild process prioritizes RAID 1+0 data first. If a second disk fails before the rebuild completes, then RAID 5DP is prioritized first. This logic represents the statistical availability model for the two failure states. Once the RAID 1+0 data has been rebuilt, the RAID group is protected against any two simultaneous disk failures. The status of a RAID 1+0 data rebuild can be displayed using Command View.

More Info at:-
http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?locale=en_US&contentType=SupportManual&docIndexId=1255&prodTypeId=12169&prodSeriesId=298817

Regards,
Syam

Re: Array configuration

Edgars Rudans — Wed, 03 Nov 2004 06:44:13 GMT

Hi Jack,

Answer will depend on you apps and IOs nature to VA. I.e. depending of disk activity and space available, AutoRAID will place/convert you data as it thinks better for you, but probably not as you have expected :) For example, in one sunny day, one could find, that large amount of data which must be written very fast, is actually placed on RAID5DP part, and one will get unexpected performance degradation.

So, my point, if you are looking for stable performance, go for RAID0+1.

Regards,
Ed