toasters April 2000

toasters@lists.teaparty.net

121 participants
139 discussions

Can VIFs work with 3Com switches?
by Chris Thompson 06 Apr '00

06 Apr '00

This is thinking a few months into the future for us, but it might be useful to know the answer now... Can one use VIFs in ONTAP together with the port trunking facilities of a 3Com SuperStack 3300 switch to treat two or more 100BaseT connections as a single interface, with load balancing at both ends? Has anyone any experience with such a configuration? Chris Thompson University of Cambridge Computing Service, Email: cet1(a)ucs.cam.ac.uk New Museums Site, Cambridge CB2 3QG, Phone: +44 1223 334715 United Kingdom.

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RE: EMC Celerra vs NetApp Filer
by Sam Schorr 04 Apr '00

04 Apr '00

Interesting. I got a different answer from my EMC engineering people. The following is a quote: "Stripes can exist either within the Sym ("meta-volume") or outside the Sym using OS (or volume management) tools. Within the Sym, if a stripe is built across Mirrored volumes, the stripe remains available provided that one does not lose both halves of the same mirror. Example, four mirrored pairs (A/a, B/b, C/c, and D/d) with a stripe built across the four. Up to four disks could be lost as long as one of each pair is still good. We will not build a meta-volume such that 2 or more parts reside on the same physical - this violates our configuration rules. Outside the Sym the same holds true provided that one does not build stripes with multiple pieces coming from the same physical. The net is - as long as the underlying parity (mirror or otherwise) maintains the availability of the parts of a stripe, the whole stripe will remain available." --srs -----Original Message----- From: Steve Gremban [mailto:gremban@msp.sc.ti.com] Sent: Tuesday, April 04, 2000 11:04 AM To: toasters@mathworks. com Subject: Re: EMC Celerra vs NetApp Filer On an EMC if a disk goes out on one side of a mirror (we'll call it side A), side A will be offline (all of the disks in side A, not just the bad drive). Therefore, any new writes will be seen on side B but not on the drives of side A and you can't use side A drives to recover from subsequent side B drive failures. My EMC SE said that only if both sides of the mirror have simultaneous drive failures taking them both down at the same time is there a chance of recovering and that it would take a lot of work. (this assumes that the bad drives weren't mirrors of each other) Brian Tao wrote: > On Mon, 3 Apr 2000, Bruce Sterling Woodcock wrote: > > > > I don't see how? When one mirror loses a disk, the whole thing is > > lost; you switch over to the other mirror, which has n-1 disks as > > the RAID 4 array. So your initial chance of failure is 2n-1 and > > then n-1 for a second failure whereas RAID 4 is just n followed by > > n-1 for the second failure To be somewhat anal about it, the initial chance of failure of mirrored partitions is 2(n-1). :) But you're right, you have a higher probability of being put at risk using a mirror (just needs 1 disk going bad out of 2n-2 disks) than with RAID4 (1 disk bad out of n disks). Once that 1st disk is lost the probabilities of a second failure are the same for both (n-1). If EMC had actually implemented their mirroring like Brian Tao mentions below then their mirroring would be much more reliable than RAID4. > > > I think you're talking about RAID 0+1 (taking a RAID-0 set and > mirroring it on another RAID-0 set, which is just silly). RAID 1+0 > does the mirroring first, then the striping/concatenation: > > +----+----+ +--------------+ +------------+ > | 1A | 1B | | RAID-1 set 1 | | | > +----+----+ +--------------+ | | > | 2A | 2B | | RAID-1 set 2 | | | > +----+----+ +--------------+ | | > | 3A | 3B | | RAID-1 set 3 | | | > +----+----+ +--------------+ | | > | 4A | 4B | --> | RAID-1 set 4 | --> | RAID 0 | > +----+----+ +--------------+ |(7 "drives")| > | 5A | 5B | | RAID-1 set 5 | | | > +----+----+ +--------------+ | | > | 6A | 6B | | RAID-1 set 6 | | | > +----+----+ +--------------+ | | > | 7A | 7B | | RAID-1 set 7 | | | > +----+----+ +--------------+ +------------+ > [etc...] > > The A's and B's are drives of a mirrored pair. You could lose, > say, drives 1A, 2A, 4B, 5B and 7A and still have a functional RAID 0, > because no single mirror is completely broken. You could lose the > entire shelf containing the A drives and not have an outage (something > from which today's Netapps cannot automatically recover, clustering or > no clustering). Having mirrored pairs in RAID 4 (i.e., having > mirrored data and parity drives) and the ability to concurrently > rebuild multiple broken mirrors to hot spares would really give Netapp > a leg up on other NAS vendors, IMHO. > > > Oh, are the drives mirror images of each-other too? I didn't > > realize that. So if Drive 1 in Mirror A fails, breaking the mirror, > > and then Drive 2 in Mirror B fails, Mirror B will be smart enough to > > switch over to Drive 2 in Mirror A? > > As far as the RAID 0 is concerned, single drive failures within > each mirrored pair does not result in that stripe being down, because > the remaining half of the mirror is still online. If you lose, say, > drives 4A and 4B in a RAID 1+0, then you're toast. In RAID 1+4 (or > 1+5), you would still have the parity drive. > > > -- > Brian Tao (BT300, taob(a)risc.org) > "Though this be madness, yet there is method in't"

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ADIC FastStor on F720
by bjf 04 Apr '00

04 Apr '00

Howdy, At my day job, I've got a F720 running 5.3.4R2. I'm trying to attach a new ADIC FastStor 7 tape library to it. The filer sees the changer and the drive: slot 0: SCSI Host Adapter 0b (Qlogic ISP 1040B) Fast/Wide, Differential Firmware Version 4.65 Clock Rate 60MHz. 1: ADIC FastStor DLT 0115 3: QUANTUM DLT8000 010F But it won't qualify the drive, even if I try using the /etc/cloned_tapes file. disk0> sysconfig -t Tape drive (0b.3) DLT8000 (Non-qualified tape drive) /etc/cloned_tapes: DLT8000 EMULATES DLT7000 (also tried QUANTUM DLT8000 EMULATES QUANTUM DLT7000). Any ideas? Hopefully my registration on now.netapp.com will come thru sometime soon... Thanks, Bryan -- Bryan Fullerton http://bryanfullerton.com/ Core Competency Samurai Consulting Can you feel the Ohmu call?

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Summary: backup recommendations
by Jeff Bryer 04 Apr '00

04 Apr '00

I had asked about software/hardware recommendations to replace our existing Budtool/DLT4000 equipment. This is for backing up NetApp filers (NDMP support a requirement), SUN servers, and a Linux cluster primarily. Ability to scale to include Netware, and NT is also important, as well as the potential to scale to cover campus-wide backups of Win9x/NT/2000, Mac and other clients. Summary of responses: Software: 1) Quick Restore from Workstation Solutions was recommended as the choice most closely resembling Budtool (licensing model, look and feel) and was thought of as having the best NDMP support today. 2) Networker from Legato, good client support but the NDMP support came last (out of the three choices). It was thought that v6 will have much better NDMP support. Plus the NDMP client pack is expected to be a free upgrade to Budtool owners (or maybe restricted to those on maintenance). 3) Netbackup from Veritas. NDMP support rated number 2, good client support. Quite a few people who had used both Legato and Veritas said they had migrated to Veritas (NDMP support being one reason). Hardware: 1) DLT, by far most people recommended using DLT[78]000s. It's established, people trust the reliability. 2) AIT, on paper specs great. Of those who've used it, some have had good results with direct attach to NetApps, others only once the library was configured in DLT emulation mode. The DLT drives may have had more recommendations but that's very much skewed as most people who responded hadn't used AIT drives. I would like to hear from more people who've actually used AIT drivs. Our current thoughts: Software choice: Veritas. The NDMP support today in Legato is not sufficient for our needs. Quick Restore doesn't have support for enough different clients, a smaller user install base, disaster recovery seemed to be more a focus for the upcoming v3 release. Hardware choice: AIT. We've had to replace our DLT7000 drive three times in the last two years, so we don't feel overlly confident about them (our 4000 stackers have been fine). The specs and road map for AIT look good (on paper). This being said, I still would like to hear from AIT users to feel better about the reliability of the media/drives. Thanks to everyone who responded. -- Jeff Bryer bryer(a)sfu.ca Systems Administrator (604) 291-4935 Academic Computing, Simon Fraser University

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Budtool, NetApp filer & Tape library
by Rainchik, Aleksandr (MED, Non GE) 04 Apr '00

04 Apr '00

Hello, We have NetApp F740. For backups we are using Budtool 4.6.1 with two media servers (Sun's) and tape library connected to them. Right now, when we are doing backups, all data bits are flying over the network from the NetApp to the media server and finally to the tape. I'm curious, if we can connect one SCSI channel from the tape library to the NetApp? And a) use it as NDMP media server b) eliminate data transfer over the network while doing NetApp backups. Any hidden traps? So, we are basically want to replace one media server with a NetApp. And my main concerns is how well NetApp is going to work this way. Can I use all those jbmgr commands to load and unload tapes there? Will index tables be updated correctly on main Budtool server? Thank you.

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Re: Messages from cron_admin about daylight saving time
by Chris Thompson 04 Apr '00

04 Apr '00

Back on Tuesday 21 March I wrote: > > We run a default raid scrub regime (01:00 on Sundays). Last Sunday we > got a message > > Sun Mar 19 01:00:00 GMT [cron_admin]: > Rescheduling raid_scrub_admin to run at Sun Mar 19 01:00:00 GMT 2000 > because of Day Light Saving time change > > [Raid scrubbing itself ran at this time with no problem.] > > Moreover, every time timed tweaks the clock (we use ntp synchronisation) > it again mutters. e.g. > > Tue Mar 21 16:04:33 GMT [cron_admin]: > Rescheduling raid_scrub_admin to run at Tue Mar 21 16:04:33 GMT 2000 > because of Day Light Saving time change > > Now all this is no doubt because next Sunday is clock-changing day > in our timezone (GB), with 2000-03-26 01:00:00 GMT -> 02:00:00 BST. > [American friends will no doubt be seeing this effect next week!] Well, they obviously didn't, and I think I understand why. Contrary to my initial impression, it seems that the USA switches at 02:00:00->03:00:00 (local time), rather than 01:00:00->02:00:00. The messages apparently only happen if the (local) time that the raid scrub is scheduled for does not logically exist. This happened in the UK and in the Republic of Ireland (I got a confirmation from Garret Flynn) and presumably in Portugal (any NetApp users there?). Further east in Europe the clock change is later in local time (because it is at the same real time, 01:00:00 UTC). For those interested: the raid scrub *did* run at the expected time on clock-changing night, and the messages then disappeared. Garret tells me that this is a known bug, 13649. Chris Thompson University of Cambridge Computing Service, Email: cet1(a)ucs.cam.ac.uk New Museums Site, Cambridge CB2 3QG, Phone: +44 1223 334715 United Kingdom.

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RE:
by Hawley, Rob 04 Apr '00

04 Apr '00

The filer only supports Microsoft NT domain controllers. There are a number of issues not just that samba does not support UNICODE in the same way NT does. -----Original Message----- From: Igor Schein [mailto:igor@txc.com] Sent: Tuesday, April 04, 2000 10:30 AM To: toasters(a)mathworks.com Subject: Hi, My goal is to to get CIFS on a 740 filer to join to PDC running on Samba. Last time I checked there was a unicode issue which was preventing people from using Samba as PDC for netapp filers. I was wondering if the status has changed and any1 on the list has been successfull in doing so. THanks Igor

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None
by Igor Schein 04 Apr '00

04 Apr '00

Hi, My goal is to to get CIFS on a 740 filer to join to PDC running on Samba. Last time I checked there was a unicode issue which was preventing people from using Samba as PDC for netapp filers. I was wondering if the status has changed and any1 on the list has been successfull in doing so. THanks Igor

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RE: How are you mounting CIFS homedirs with Win9x?
by Uren, Jim 04 Apr '00

04 Apr '00

[snip] > > Thanks for the info. Are there any plans to support variable > expansion a la > SAMBA? For example, sample allows you to define a share using > "%u", which > gets expanded to the username on the SAMBA side. That llows you to put > "\\samba-server\\home" in the logon script, and have SAMBA do the > exapansion for you. > > Tim Yes, this capability is in-plan. The bug report (burt) number for this RFE is 13856.

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Re: EMC Celerra vs NetApp Filer
by Todd C. Merrill 04 Apr '00

04 Apr '00

Kendall Libby wrote: > > right now. Going by units of "1 cpu, 1gb cache, 200gb disk", EMC > > comes in cheaper after a small number of units. For us. YMWV. Bruce Sterling Woodcock wrote: > But these wouldn't be units that would be equal comparison. > What matters is primarily ops/$ and GB/$ for roughly the same Kendall indeed pointed out one "unit" measure, combining performance and storage, that works well *for us*. ops/$ and GB/$ may not be a primary concern for everyone [0], nor may it be a majority concern [1]; I don't think it's fair to make such a blanket statement. There are subjective factors, of course. And, if you ask NetApp for their super-duper maintenance and support plans with bacon and extra cheese, in order to try to narrow the service level gap and compare apples-to-apples with what EMC offers by default, the price gap narrows quite a bit, too. Bruce wrote: > not doubting what you say; I'm just annoyed customers are > comparing the two and yet don't appear to have numbers on > this. [...] > Since we don't know how much all the EMC and related stuff cost, it's > hard to accurately compare the two solutions. I bet it is much higher, [...] > Personally I don't mind who prefers what just so long as all the facts > are on the table. Vendor quotes are often confidential, and info gained from NDA's certainly are, so release of numbers can be a big no-no. In a public forum, we can only quote list prices and independent performance numbers and currently shipping features. But here, as in our personal consumer lives, "nobody pays list price." ;) It's hard to make an orange look like an apple; and, it's equally hard to make a pear look like an apple, too. Vendors in a comparison have to be sqeeuzed into a framework that is not complementary to any of them. Apples-to-apples comparisons are very difficult when the paradigms and company philosophies are vastly different, too. If we were talking about CheapPCDiskDriveVendor #1 and #2, it might come down soley to parameter/$ and we probabaly wouldn't be having this interesting discussion. ;) [0] I ran across this quote this weekend which was rather interesting: "There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man's lawful prey." --John Ruskin [2] [1] I'm with Brian (?) on the ops issue, though. More, more, more! [2] I'm not commenting on either vendor in question specifically. I just thought it was a nice thought to think about since so many people get wrapped up in one thing ($) when making purchases, for business or pleasure. Step back from the tree and look at the forest. Until next time... The Mathworks, Inc. 508-647-7000 x7792 3 Apple Hill Drive, Natick, MA 01760-2098 508-647-7001 FAX tmerrill(a)mathworks.com http://www.mathworks.com ---

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toasters April 2000