INFO-VAX Sun, 06 Jul 2008 Volume 2008 : Issue 375 Contents: Re: Great External Article on A-A Clustering Re: Happy Independence Day Re: HELP text error for ANALYZE/MEDIA Re: VMS SAN Primer ---------------------------------------------------------------------- Date: Sun, 6 Jul 2008 07:46:18 -0700 (PDT) From: IanMiller Subject: Re: Great External Article on A-A Clustering Message-ID: <21a69e5f-9315-4680-9572-85383e119773@25g2000hsx.googlegroups.com> On Jul 5, 1:24=A0am, "Main, Kerry" wrote: > The readers of this list may be interested in this external article extra= cted from > Sue's latest update. > > http://www.availabilitydigest.com/public_articles/0306/openvms.pdf > > One of the best articles I have seen on active-active OpenVMS clustering. > > Regards > > Kerry Main > Senior Consultant > HP Services Canada > Voice: 613-254-8911 > Fax: 613-591-4477 > kerryDOTmainAThpDOTcom > (remove the DOT's and AT) > > OpenVMS - the secure, multi-site OS that just works. It is a good article and deserves some more publicity. I posted this waaay back on the 16 of June http://www.openvms.org/stories.php?story=3D08/06/16/3139809 and subsequently have read several other articles form the Availability Digest site. That site is well worth exploring. ------------------------------ Date: Sun, 6 Jul 2008 10:14:52 -0700 (PDT) From: pos Subject: Re: Happy Independence Day Message-ID: <318e80b2-c1ba-4e43-93a1-88211341f721@y21g2000hsf.googlegroups.com> > > > > As far as I know, Qu=E9bec has not yet declared independance, > > Qu=E9becois think they already have...unilaterally. ------------------------------ Date: Sun, 6 Jul 2008 07:43:53 -0700 (PDT) From: IanMiller Subject: Re: HELP text error for ANALYZE/MEDIA Message-ID: On Jul 5, 11:22=A0pm, David J Dachtera wrote: > gerr...@no.spam.mail.com wrote: > > > Hello everyone, > > > I've just discovered an error in the help text for the ANALYZE/MEDIA co= mmand > > (the bad block locator utility) on both Alpha and Itanium V8.3 releases= . > > > There are two almost identical copies of the same text, except for some= slight > > changes: different case for the BAD acronym and the sentence "This manu= al is > > posted with other archived manuals on the OpenVMS Documentation website= " added > > to the second copy. > > > I think it's not a serious error, but it makes difficult to search for = command > > subtopics because ANALYZE/MEDIA is considered ambiguous. > > > I'm a Hobbyist, so I do not have any support contract. How can I signal= this > > problem to HP Engineering to have it corrected? > > > Thanks, > > G. (not english native, sorry for any errors) > > Note also that ANALYZE/MEDIA is, for the most part, obsolete. Only very > old media do not provide for bad block replacement local to the drive. > > For modern SCSI and FC disks, low-level format is the preferred way to > verify/refresh the device's bad block list. > > D.J.D. try posting a message using the feedback form on the HP VMS site http://h71000.www7.hp.com/fb_business.html I use ANAL/MEDIA/EXER=3DFULL as a way of erasing disks or as a way of testing them. ------------------------------ Date: Sun, 6 Jul 2008 07:49:09 -0700 (PDT) From: IanMiller Subject: Re: VMS SAN Primer Message-ID: <2a974e23-ebc4-478b-a876-a3fe43ff1a19@a1g2000hsb.googlegroups.com> On Jul 6, 3:31=A0am, Michael Austin wrote: > David J Dachtera wrote: > > JF Mezei wrote: > >> Paul Lentz wrote: > > >>> I sorta knew there couldn't be much difference... > >> But wait a minute, don't SANs use very different terminology. They tal= k > >> about switches, fabric etc . > > > True. However, the terminolgy has become very confused (confusing). > > > When folks say "SAN", they really mean "storage array". > > > When folks say "fibre channel", they really mean "storage area network" > > (SAN - as in the interconnecting infrastructure). > > > ...and "a separate 'fabric'" equates roughly to a VSAN (Virtual Storage > > Area Network), corrolary to a VLAN. VSANs taking "zoning" to another > > level, as it were. On CI or over Ethernet, the VMS equivalent would be > > the cluster id. number. > > >> And don't SANs have many many capabilities such as RAID, abilities to > >> comvine physical disks into a single drive, or partition a single driv= e > >> into multiple drives ? > > > Yes. Think: "HSG" or SWXCR. > > >> Do SANs provide any concept of shared locking ? > > > Does a CI provide such a concept? ...shared SCSI...? > > >> Can a node request that > >> a block on a drive be locked for writes by other nodes ? > > > Within the confines of an operating "domain" such as a VMS cluster, > > certainly. However, it requires a distributed lock manager. > > >> Or is it pretty much a total free for all with SANs just blindly > >> executing requests on any drive from any node ? > > > In so far as "drive" and "node" are virtual concepts, yes. However, > > there is no "magic" which enables sharing. Read on... > > >> (I would assume that SANs would have ability to provide "views" which > >> means that a particular node woudl have a defined list of disks it can > >> access ? > > > Yes and no. "LUNs" (remember: FC is just a way to carry the SCSI > > protocol over a light "beam") are "mapped" to specific fibre adapters > > ("FA" for short, in the parlance) on the storage array, and "masked" fo= r > > access by specifc HBAs (by WWID). > > >> Or can it go and peak at disk drives that have been assigned to > >> other nodes ? > > > Zoning, mapping and masking restrict "visibility" between specific HBAs > > and LUNs. > > >> Seems to me that there would be a large number of management issues to > >> deal with that would not be needed in case of a VMS cluster. A VMS > >> cluster offers a single security concept, shared locking etc. When you > >> have different seperate nodes accesing drives in a SAN, those are no > >> longer applicable. > > > Well, you're confusing SANs with MSCP-served storage. > > > The best way to think of a storage array is as if a tremendously > > talented SWXCR were housed in a rack/frame with fairly large number of > > physical drives. The physical drives are grouped together by the array > > manager (a person, that is) into virtual devices. Think: RAIDsets, > > mirrored RAIDsets (5+1 for example) and mirrored stripe sets. Quite > > literally, a superset of what's available on an HSJ, HSZ or HSG. Those > > virtual devices are thent presented to specific hosts via zoning, > > mapping and masking. > > > ...however, it is just storage. A LUN. It's still up to the host > > operating environment to manage that storage. Such management is NOT th= e > > array's job in a FCSF/SAN anymore than it would be in an HSJ on a > > CI-based storage array. The array simply presents storage. Each LUN > > appears to the host as if it were a separate "SCSI" device. A "LUN" may > > occupy a portion of each disk in a disk group (in EVA parlance), for > > example. VMS, Windows, UX, AIX, etc. only "sees" a SCSI device over FC > > ($1$DGAnnnnn:), while the actual storage presented may consist of a > > RAIDset or a stripeset, with or without mirroring (on the array, not > > HBVS). > > > There's no "magic" in a FCSF SAN which can allow incompatible operating > > environments to either co-exist or share storage devices. The > > limitations of each operating environment transcend the storage domain, > > regardless. > > > Clear as mud, eh? > > > Thought so... > > > D.J.D. > > I took a job a few years ago doing Sysadmin on OpenVMS on SAN. =A0Looking > at the SAN - it is essentially a smart Star-coupler. =A0It directs traffi= c > to only those arrays and "devices (aka LUN)" you have specified. Once > the pointers are set - it is very very easy... > > The SAN Switches make up a fabric - which is nothing more than a fiber > network. =A0Your HBA's can attach to the same fabric - or redundant > fabrics. Blue/Red for example. > > This is an over-simplification, but hopefully you get the idea... Read the presentation on Data networking and Storage Networking on the XDelta site http://www.hpug.xdelta.co.uk/ ------------------------------ End of INFO-VAX 2008.375 ************************