toasters March 2011

toasters@lists.teaparty.net

31 participants
15 discussions

SAN for SAS
by Raj Patel 12 Mar '11

12 Mar '11

Hi, A bit of a generic SAN question (not necessarily NetApp specific). I've got a team of 40 people who use a statistical analysis package (SAS) to crunch massive time-series data sets. They claim their biggest gripe is disk contention - not necessarily one person using the same data but 40. So they process these data-sets locally on high-spec PC's with several disks (one for OS, one for scratch, one for reads and one for writes). I think they'd be much better off utilising shared storage (ie a SAN) in a datacenter so at least the workloads are spread across multiple spindles and they only need to copy or replicate the data within the datacenter rather than schlep it up and down the WAN which is what they currently do to get it to their distributed team PC's. Are there any useful guides or comparisons for best practise in designing HPC environments on shared infrastructure ? Other than knowing what SAS does I'm not sure on its HPC capabilities (ie distributed computing, clustering etc) so I'll need to follow that angle up too. Thanks in advance, Raj.

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Re: SAN for SAS
by McDonald, Alex 11 Mar '11

11 Mar '11

Iirc (and I'd check since my info may be out of date) SAS 50/50 is only that over the long run; it does a lot of reads (up to entire analysis sets) followed by a lot of writes, with quite a bit of IO to temporary files too. It can be quite a handful to manage on shared storage. You need a good understanding of the app to be able to size it properly. Alex McDonald NetApp, Office of the CTO Send on a bb, excuse the typos ----- Original Message ----- From: Raj Patel <phigmov(a)gmail.com> To: Maxwell Reid <max.reid(a)saikonetworks.com> Cc: toasters(a)mathworks.com <toasters(a)mathworks.com> Sent: Fri Mar 11 20:16:12 2011 Subject: Re: SAN for SAS Hi Max, There are a couple of issues for these guys - * Long copy times for the datasets from the data-center to their workstations * Long processing times for i/o intensive SAS processes on their PC - they're just using SAS Workstation and batching up the work themselves (ie not distributed by design but by necessity) WAN circuit costs are pricey so ideally we'd centralise their workloads - powerful SAS server plus plenty of disk or even 40 servers with individual workstation licenses (either VDI, Citrix or real) and shared disk. Their theory is that their tasks aren't necessarily CPU bound but disk i/o bound. SSD's are fine for reads but they're skeptical about writes. SAS apparently supports RAM disks but they're pretty pricey for the size they'd need. A bit of googling indicates SAS has a distributed processing mechanism. I'll have to chat to them about licensing (suspect its not cheap). Anyone using their SAN's for storing or running weather, population or financial simulations (ie massive data-sets with a 50/50 mix of reads/writes) ? Cheers to all for the tips so far ! Raj. On 3/12/11, Maxwell Reid <max.reid(a)saikonetworks.com> wrote: > HI Raj, > > Would I be correct in assuming that the main problem you're trying to solve > is reducing the replication via WAN to the local machines? > > In this case, moving the processing nodes to 40 machines in the datacenter > with or without a shared storage arrangement would fix that issue; RPC or > protocol based replication between nodes would be required unless you're > going to switch to a clustered filesystem or network filesystem. In this > case a SAN or NAS setup would work fine. > > From the HPC side of things, sticking a bunch of PCIe SSDs in the nodes and > connecting them together via 10GbE or Infiniband would certainly speed > things up without the need for a shared disk pool, but that's probably > overkill for what you're trying to accomplish. > > > ~Max > > > > > On Fri, Mar 11, 2011 at 10:43 AM, Raj Patel <phigmov(a)gmail.com> wrote: > >> Hi, >> >> A bit of a generic SAN question (not necessarily NetApp specific). >> >> I've got a team of 40 people who use a statistical analysis package >> (SAS) to crunch massive time-series data sets. >> >> They claim their biggest gripe is disk contention - not necessarily >> one person using the same data but 40. So they process these data-sets >> locally on high-spec PC's with several disks (one for OS, one for >> scratch, one for reads and one for writes). >> >> I think they'd be much better off utilising shared storage (ie a SAN) >> in a datacenter so at least the workloads are spread across multiple >> spindles and they only need to copy or replicate the data within the >> datacenter rather than schlep it up and down the WAN which is what >> they currently do to get it to their distributed team PC's. >> >> Are there any useful guides or comparisons for best practise in >> designing HPC environments on shared infrastructure ? >> >> Other than knowing what SAS does I'm not sure on its HPC capabilities >> (ie distributed computing, clustering etc) so I'll need to follow that >> angle up too. >> >> Thanks in advance, >> Raj. >> >

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Do I need to update diagnostics firmware?
by Ray Van Dolson 10 Mar '11

10 Mar '11

About to bump my N3600 A20 (FAS 2050C) from Data ONTAP 7.3.1 to 7.3.5.1. Our BIOS and BMC are current at 3.0 and 1.2 respectively, but our diagnostics firmware is at 5.3.6 (the latest is 5.4.6). Couple of questions: - Should I really update the Diagnostics firmware, or do many of you just leave it as-is if you're at the latest BIOS anyways? - Is it possible to update the Diagnostics firmware only (don't reflash the BIOS, etc) and somehow avoid needing to fail-over to my other controller and reboot? Thanks! Ray

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Deduplication limit on 2040
by Milazzo Giacomo 10 Mar '11

10 Mar '11

Hi all, on FAS2040 with DoT 7 the size limit for a volume with A-SIS enabled is 3 TB. I read that with DoT 8.0.1 this limit has been extended to 16 TB (note, the limit with A-SIS enabled, not the vol size limit!) but nowhere I find that this can be done ONLY if containing aggregate is 64 bit. So, question is: to have a deduplicated volume on a 2040 bigger that 3 TB and up to 16 TB the containing aggregate has to be 64 bit? Thanks, PS) I think so because with 32 bit aggregate you cannot dedup a 16 TB vol (max size of the vol) because in this case no space is left on volume/aggr to dedup.

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SAN data migration
by Milazzo Giacomo 06 Mar '11

06 Mar '11

Hi all, once upon a time there was "ReplicatorX"...and now? :) Anyway I've never used it and I don't know about its pros and cons. I should plan a SAN data migration from dozens of servers and hundreds of LUNs on HP EVA 5000, IBM DS 4800, EMX CX700 and 300 and so on... ...and all of this has to be performed online, with no disruption, better if agentless (os are Windows, Linux, AIX and more, cluster based on Windows, RHEL, Suse, Oracle...) Just one restart could be admitted for each systems... Any suggestion, tools ... Thanks in advance,

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toasters March 2011