How to change RAID level in production server (Hardware RAID)

senthil_kumar_1 — Tue, 29 Nov 2011 15:30:47 GMT

Hi All,

My server Details:

Hardware: ProLiant DL385 G7

OS: RHEL 5

RAID cotroller: HP Smart Array P410i Controller

HDDs: Four disks with 600GB (each)

RAID 0 is configured:

# cat /proc/driver/cciss/cciss0
cciss0: HP Smart Array P410i Controller
Board ID: 0x3245103c
Firmware Version: 3.66
IRQ: 162
Logical drives: 1
Sector size: 2048
Current Q depth: 0
Current # commands on controller: 0
Max Q depth since init: 159
Max # commands on controller since init: 159
Max SG entries since init: 31
Sequential access devices: 0

cciss/c0d0: 600.09GB RAID 0

Only one HDD is used in RAID 0:

# hpacucli controller slot=0 physicaldrive all show

Smart Array P410i in Slot 0 (Embedded)

array A

physicaldrive 2C:1:1 (port 2C:box 1:bay 1, SAS, 600 GB, OK)

unassigned

      physicaldrive 2C:1:2 (port 2C:box 1:bay 2, SAS, 600 GB, OK)
      physicaldrive 2C:1:3 (port 2C:box 1:bay 3, SAS, 600 GB, OK)
      physicaldrive 2C:1:4 (port 2C:box 1:bay 4, SAS, 600 GB, OK)

My Questions:

1)Can I change RAID configuration with out data loss like RAID 1 / RAID 5?

2)Can we include other HDDs in to existing RAID 0?

3)If we can not include other HDDs in to existing RAID 0, then how can we use those HDDs (hdd space)?

Re: How to change RAID level in production server (Hardware RAID)

Matti_Kurkela — Wed, 30 Nov 2011 22:52:12 GMT

1.) Maybe: if your Smart Array P410i has a write cache unit installed, it can convert the RAID set to another RAID level without loss of data if the disk configuration is appropriate for the new RAID level. Some conversions *may* be possible without the write cache unit, too: I don't remember the exact details (check the SmartArray documentation).

To see if your Smart Array includes a write cache unit, please run:

# hpacucli controller slot=0 show config detail

...and see if it includes any mention about write cache (either BBWC or FBWC).

2.) Yes, the extension of the existing RAID array to new disks is possible.

3.) You could use the unassigned disks to form one or more new arrays (e.g. a single three-disk RAID 5 or RAID 0 array, or one RAID 1 mirror set + one single non-RAID disk, or even three separate one-disk "arrays").

All these can be done with hpacucli, but the web-GUI-based ACU tool might be easier to use.

Step-by-step procedure for the ACU available here:

http://h20565.www2.hp.com/portal/site/hpsc/template.PAGE/public/psi/mostViewedDisplay/?sp4ts.oid=3902574&spf_p.tpst=psiContentDisplay&spf_p.prp_psiContentDisplay=wsrp-navigationalState%3DdocId%253Demr_na-c02836351%257CdocLocale%253Den_US&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken

The main document for hpacucli and the graphical ACU:

http://h20565.www2.hp.com/portal/site/hpsc/template.BINARYPORTLET/public/kb/docDisplay/resource.process/?spf_p.tpst=kbDocDisplay_ws_BI&spf_p.rst_kbDocDisplay=wsrp-url%3Dhttp%253A%252F%252F16.238.8.173%253A25654%252Fsp4tssearch%252FbinaryDocDisplay%253FdocId%253Demr_na-c00729544%2526docLocale%253Den%26wsrp-requiresRewrite%3Dfalse&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken

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How to change RAID level in production server (Hardware RAID)

Re: How to change RAID level in production server (Hardware RAID)