topic re : DS2300 mirroring in Operating System - HP-UX

re : DS2300 mirroring

Vincent_5 — Sat, 28 Jun 2008 12:16:57 GMT

Hi Guys,
Can anyone of you advice if this is workable, I have a rp7410 install with 2 4si card and 2 DS2300 . I have connected each of the DS2300 with full bus via 1 x scsi port on each of the 4si on eaxh server. on each of the DS2300 there are 4 x 36BG disk and 6 x 72GB disk . How can I mirror one DS2300 to another DS2300, will disk mirroring solve the problem ??? CAn the mirroring be done through sam or can someone give me some steps to do it ??

Regards
Vincent

Re: re : DS2300 mirroring

TTr — Sat, 28 Jun 2008 14:12:08 GMT

The only way you can mirror disks across the DS2300 the way you have it wired it to use LVM or VxVM mirroring. Both are optional products for HP-UX.

I don't know why you wired it the way you did but you are very underutilizing the 4si cards. You can still mirror and stripe within each 4si card and within each ds2300 but that would be on the same single SCSI bus and would be very inefficient.

Ideally you would connect both buses of the ds2300 on the same 4si to double the i/o bandwidth and mirror the disks from one scsi bus to the other within each 4si.

Re: re : DS2300 mirroring

Andrew Rutter — Sat, 28 Jun 2008 21:15:10 GMT

hi,

you will find some useful info on this thread

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=148533

Andy

Re: re : DS2300 mirroring

Vincent_5 — Sun, 29 Jun 2008 08:08:43 GMT

Hi Guys,
Thanks for the info, but the actually intention is to have the DS2300 running on full bus and reduntency for each disk on the DS2300. But, I don't know whether is this a supported configuration for HP. Please advice??

Regards
Vincent

Re: re : DS2300 mirroring

TTr — Sun, 29 Jun 2008 10:33:25 GMT

I don't see anything wrong as far as support from HP. For supported features and other info refer to
http://docs.hp.com/en/J6173-90007/J6173-90007.pdf
Ensure that you have the latest firmware installed on the 4si adapters(page 53) and the latest 4si software installed on the server.
Also avoid the setup on page 40.

You still have to create logical drives out of each physical drive (I don't think the 4si have a passthrough feature). If your intent is to mirror each physical disk from one ds2300 to the other, you can still do it but you have to create a raid0 logical disk for each physical disk. On page 22 of the above document, raid0 is supported with a single drive.

As I said before this is a very inefficient way of using the 4si adapters, you will be using 25% of the i/o bandwidth of the 4si. Simple LVD SCSI adapters would do what you want just as well but I guess you have the 4si but not the SCSI adapters.

Re: re : DS2300 mirroring

TTr — Sun, 29 Jun 2008 10:43:41 GMT

Of course as I said in my first reply, after you create the logical drives in each 4si, you have to mirror them on the OS level using software mirroring, LVM or VxVM. You can not mirror across the two 4si adapters using the 4si hardware.

Re: re : DS2300 mirroring

Vincent_5 — Mon, 30 Jun 2008 05:06:12 GMT

Hi TTR,
Thanks for the info, can I check one more thing, do you happen to have the part no. to the scsi cable that is use for connecting the DS2300 scsi port to the 4si scsi port . Please advice??

Regards
Vincent

Re: re : DS2300 mirroring

TTr — Mon, 30 Jun 2008 17:40:23 GMT

The C2372A should be the right cable. It is shown in
http://www.hp.com/products1/evolution/e3000/download/52430406b.pdf

The doc is for the e3000 server platform but it mentions rp servers and from the hardware perspective it should be the right cable.

Re: re : DS2300 mirroring

TTr — Mon, 30 Jun 2008 17:41:49 GMT

Typo. The cable is C2373A.