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RE: Mixed disk sizes within a single aggregate
by Fox, Adam 25 Sep '06

25 Sep '06

The -g option works when an RG already exists and you want to back-fill it. It doesn't create a new RG. To create a new RG, reduce the RG size and add drives, then up it to what you want. -- Adam Fox adamfox(a)netapp.com -----Original Message----- From: George, Andrew [mailto:georgea@anz.com] Sent: Sunday, September 24, 2006 9:02 PM To: Sto RageC ; Brosseau, Paul Cc: Jeff Mery; toasters(a)mathworks.com Subject: RE: Mixed disk sizes within a single aggregate That should work, I'd be more inclined to go aggr add aggr0 -g rg2 -d <disk list> (Then again, I've always been distrustful of adding disks without naming them explicitly) -----Original Message----- From: owner-toasters(a)mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Sto Rage(c) Sent: Saturday, 23 September 2006 2:53 AM To: Brosseau, Paul Cc: Jeff Mery; toasters(a)mathworks.com Subject: Re: Mixed disk sizes within a single aggregate On 9/20/06, Brosseau, Paul <Paul.Brosseau(a)netapp.com> wrote: > > > Mixing disk sizes in an aggregate is not a problem as long as you > create RAID groups for each kind of disk. WAFL creates stripes at the > RAID group level. For best results create complete RAID groups each > time you add disks to an aggregate. > > Paulb Paul and others, Is there way to force an aggregate to start a new RAID group when an existing RAID group is not completely full. Here's a situation FAS270 with 2 shelves with 144GB FC drives. RG size is set to 16 for a single aggregate with 26 disks (2 spares). This resulted in 2 RAID groups, 1 with 16 disks and the other with 10. Now we plan to add a 3rd shelf with 300GB FC drives. If we do the regular "aggr add" it will first add the 2 spare 144GB drives, then add 4 new 300GB drives by right sizing them to match the 144GB ones. In order to maximize the capacity on this aggregate, I'd prefer to add 12 of the new drives to a new RAID group but within the same aggregate. Is something like this possible? Haven't tried this as we don't have the new shelf yet, but can I reduce the raidsize option for the aggregate from 16 to 12, then add the 2 existing spares such that that the 2nd raid-group is now full based on raidsize=12 option. Now add the new shelf and run "aggr add aggr0 12" to add 12 new 300GB drive leaving 2 spares? RAID group /aggr0/plex0/rg0 - 16 disks (144GB each) RAID group /aggr0/plex0/rg1 - 12 disks (144GB each) <-- add the existing 2 spares RAID group /aggr0/plex0/rg2 - 12 disks (300GB each) Spares - two new 300GB drives. I think it would work, any comments? -G "This e-mail and any attachments to it (the "Communication") is, unless otherwise stated, confidential, may contain copyright material and is for the use only of the intended recipient. If you receive the Communication in error, please notify the sender immediately by return e-mail, delete the Communication and the return e-mail, and do not read, copy, retransmit or otherwise deal with it. Any views expressed in the Communication are those of the individual sender only, unless expressly stated to be those of Australia and New Zealand Banking Group Limited ABN 11 005 357 522, or any of its related entities including ANZ National Bank Limited (together "ANZ"). ANZ does not accept liability in connection with the integrity of or errors in the Communication, computer virus, data corruption, interference or delay arising from or in respect of the Communication."

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RE: Mixed disk sizes within a single aggregate
by Glenn Walker 25 Sep '06

25 Sep '06

Been a while since I checked, but I'm pretty sure that aggr add is the command he's looking for. You can set the raidgroup size down to the number of disks you currently have, then add a new RG - but it will be the same size as the current setting. Glenn -----Original Message----- From: owner-toasters(a)mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of John Stoffel Sent: Friday, September 22, 2006 3:16 PM To: Sto Rage(c) Cc: Brosseau, Paul; Jeff Mery; toasters(a)mathworks.com Subject: Re: Mixed disk sizes within a single aggregate >>>>> "Sto" == Sto Rage(c) <" <netbacker(a)gmail.com>> writes: Sto> Paul and others, Sto> Is there way to force an aggregate to start a new RAID group Sto> when an existing RAID group is not completely full. Certainly, just specify explicity which disks you want in the aggregate: aggr create aggr300gb -d 12@300 See the output of 'aggr create<return>' John

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RE: Mixed disk sizes within a single aggregate
by George, Andrew 25 Sep '06

25 Sep '06

That should work, I'd be more inclined to go aggr add aggr0 -g rg2 -d <disk list> (Then again, I've always been distrustful of adding disks without naming them explicitly) -----Original Message----- From: owner-toasters(a)mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Sto Rage(c) Sent: Saturday, 23 September 2006 2:53 AM To: Brosseau, Paul Cc: Jeff Mery; toasters(a)mathworks.com Subject: Re: Mixed disk sizes within a single aggregate On 9/20/06, Brosseau, Paul <Paul.Brosseau(a)netapp.com> wrote: > > > Mixing disk sizes in an aggregate is not a problem as long as you > create RAID groups for each kind of disk. WAFL creates stripes at the > RAID group level. For best results create complete RAID groups each > time you add disks to an aggregate. > > Paulb Paul and others, Is there way to force an aggregate to start a new RAID group when an existing RAID group is not completely full. Here's a situation FAS270 with 2 shelves with 144GB FC drives. RG size is set to 16 for a single aggregate with 26 disks (2 spares). This resulted in 2 RAID groups, 1 with 16 disks and the other with 10. Now we plan to add a 3rd shelf with 300GB FC drives. If we do the regular "aggr add" it will first add the 2 spare 144GB drives, then add 4 new 300GB drives by right sizing them to match the 144GB ones. In order to maximize the capacity on this aggregate, I'd prefer to add 12 of the new drives to a new RAID group but within the same aggregate. Is something like this possible? Haven't tried this as we don't have the new shelf yet, but can I reduce the raidsize option for the aggregate from 16 to 12, then add the 2 existing spares such that that the 2nd raid-group is now full based on raidsize=12 option. Now add the new shelf and run "aggr add aggr0 12" to add 12 new 300GB drive leaving 2 spares? RAID group /aggr0/plex0/rg0 - 16 disks (144GB each) RAID group /aggr0/plex0/rg1 - 12 disks (144GB each) <-- add the existing 2 spares RAID group /aggr0/plex0/rg2 - 12 disks (300GB each) Spares - two new 300GB drives. I think it would work, any comments? -G "This e-mail and any attachments to it (the "Communication") is, unless otherwise stated, confidential, may contain copyright material and is for the use only of the intended recipient. If you receive the Communication in error, please notify the sender immediately by return e-mail, delete the Communication and the return e-mail, and do not read, copy, retransmit or otherwise deal with it. Any views expressed in the Communication are those of the individual sender only, unless expressly stated to be those of Australia and New Zealand Banking Group Limited ABN 11 005 357 522, or any of its related entities including ANZ National Bank Limited (together "ANZ"). ANZ does not accept liability in connection with the integrity of or errors in the Communication, computer virus, data corruption, interference or delay arising from or in respect of the Communication."

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RE: Mixed disk sizes within a single aggregate
by Brosseau, Paul 22 Sep '06

22 Sep '06

Mixing disk sizes in an aggregate is not a problem as long as you create RAID groups for each kind of disk. WAFL creates stripes at the RAID group level. For best results create complete RAID groups each time you add disks to an aggregate. Paulb ________________________________ From: Jeff Mery [mailto:jeff.mery@ni.com] Sent: Wednesday, September 20, 2006 3:30 PM To: toasters(a)mathworks.com Subject: Mixed disk sizes within a single aggregate Greetings fellow toasters! <Background> We're looking at moving our 2 FAS940 systems from tradtional volumes to flexvols + aggregates. </Background> It would seem to me that the same rules and guidelines for creating traditional volumes now apply directly to the aggregate level (for the most part). By rules and guidelines I mean things like trying not to mix disk sizes, try to avoid volumes (now aggregates?) that span FC adapters, etc. Are any of these things still a concern on modern versions of ONTAP (7+)? Does anyone have any best practices they'd be willing to share in regards to aggregate creation? NOW says "make them as big as possible using as many spindles as possible", but that doesn't really help much. We use our filers for unstructured data only; cifs + nfs but no databases, no snapmirror, no snapvault, etc.. TIA, Jeff Mery - MCSE, MCP National Instruments ------------------------------------------------------------------------ - "Allow me to extol the virtues of the Net Fairy, and of all the fantastic dorks that make the nice packets go from here to there. Amen." TB - Penny Arcade ------------------------------------------------------------------------ -

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Response time measurement
by Willeke, Jochen 22 Sep '06

22 Sep '06

Hi folks, i am still thinking about some figures which help me considering different fileservers. After doing some research i think one point is the response time given by the system. I did a lot of testing with sio and but the results i got are some kind of strange. A test with SIO e.g. brings following result: ./sio_ntap_linux 100 0 8k 100m 10 1 /mnt/test15 Version: 3.00 SIO_NTAP: Inputs Read %: 100 Random %: 0 Block Size: 8192 File Size: 104857600 Secs: 10 Threads: 1 File(s): /mnt/test15 Outputs IOPS: 114578 KB/s: 916626 IOs: 1145782 Terminating threads ...Killed First there are the KB/S. Much to fast even for a 1Gbit network. And the second is the response time. I calculated the following: 1s / 114578 (IOPS) = 0,00872 ms (response time) This cannot be true at all :-) Does SIO read the same block all the time (due to 0%random read), or do i have any kind of mistake in my test?!? Perhaps someone can help. Best Regards and a nice weekend Jochen

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RE: Mixed disk sizes within a single aggregate
by Fox, Adam 22 Sep '06

22 Sep '06

That works just fine. Just be aware that if you are using RAID-DP you want to start with 3 disks, not two. -- Adam Fox adamfox(a)netapp.com -----Original Message----- From: Sto Rage(c) [mailto:netbacker@gmail.com] Sent: Friday, September 22, 2006 12:53 PM To: Brosseau, Paul Cc: Jeff Mery; toasters(a)mathworks.com Subject: Re: Mixed disk sizes within a single aggregate On 9/20/06, Brosseau, Paul <Paul.Brosseau(a)netapp.com> wrote: > > > Mixing disk sizes in an aggregate is not a problem as long as you > create RAID groups for each kind of disk. WAFL creates stripes at the > RAID group level. For best results create complete RAID groups each > time you add disks to an aggregate. > > Paulb Paul and others, Is there way to force an aggregate to start a new RAID group when an existing RAID group is not completely full. Here's a situation FAS270 with 2 shelves with 144GB FC drives. RG size is set to 16 for a single aggregate with 26 disks (2 spares). This resulted in 2 RAID groups, 1 with 16 disks and the other with 10. Now we plan to add a 3rd shelf with 300GB FC drives. If we do the regular "aggr add" it will first add the 2 spare 144GB drives, then add 4 new 300GB drives by right sizing them to match the 144GB ones. In order to maximize the capacity on this aggregate, I'd prefer to add 12 of the new drives to a new RAID group but within the same aggregate. Is something like this possible? Haven't tried this as we don't have the new shelf yet, but can I reduce the raidsize option for the aggregate from 16 to 12, then add the 2 existing spares such that that the 2nd raid-group is now full based on raidsize=12 option. Now add the new shelf and run "aggr add aggr0 12" to add 12 new 300GB drive leaving 2 spares? RAID group /aggr0/plex0/rg0 - 16 disks (144GB each) RAID group /aggr0/plex0/rg1 - 12 disks (144GB each) <-- add the existing 2 spares RAID group /aggr0/plex0/rg2 - 12 disks (300GB each) Spares - two new 300GB drives. I think it would work, any comments? -G

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RE: Mixed disk sizes within a single aggregate
by Glenn Walker 22 Sep '06

22 Sep '06

Technically, doing any of this (mixing drive speeds in RGs or drive sizes in RGs) will work just fine. The only issue is the potential of performance degradation in the future once\if the system is under stress. The drives spinning slowest will take the longest to have writes flushed to them - thusly forcing the CP to take longer and impacting the entire system. This is true within RGs or across multiple RGs in an aggregate. Heck, this is true even if you have multiple aggregates and one is comprised of slower disks than the others (or is slow due to other reasons such as workload, fragmentation, etc) - a write (CP) is a GLOBAL ENTITY and it is atomic in nature: if you have data in a CP for multiple RGs\TradVols\Aggrs and one takes forever to flush to disk, then the WHOLE CP takes forever. That said, all of this 'chicken little\sky falling' stuff is just conjecture. On a lightly loaded system, you'll never see issues. Only under stress will all of this stuff bubble to the surface. Oh - and FWIW, if you write data in a less-than optimal fashion, then subsequent reads will have the same issues (higher latencies), potentially causing performance problems. Remember - all of this could still take place and you could potentially never see the effects depending on the circumstances and how the applications handles increased latencies. I hope all of that is clearly written? Glenn -----Original Message----- From: maclean(a)cs.mcgill.ca [mailto:maclean@cs.mcgill.ca] Sent: Thursday, September 21, 2006 2:41 PM To: Glenn Walker Cc: toasters(a)mathworks.com Subject: RE: Mixed disk sizes within a single aggregate I always thought you would have problems mixing speeds in a raid group. Specifically you would see 'failing servo motor' autosupport messages. Or are you suggesting raid groups segregated by speed and only mixing speeds within an aggregate made up of the speed based raid groups? -Matthew On Thu, September 21, 2006 11:01 am, Glenn Walker wrote: > Exactly :) > > > Consistency is key: always try to keep same disk sizes speeds in > aggregates. I'd feel more comfortable adding disks with faster speeds > than larger sizes - there will be no future performance degradation from > this. > > Glenn > > > > -----Original Message----- > From: Crawford, Mark (CBC) [mailto:Mark.Crawford@CapBlueCross.COM] > Sent: Thu 9/21/2006 10:53 AM > To: David Knight; Glenn Walker > Cc: Paul.Brosseau(a)netapp.com; jeff.mery(a)ni.com; toasters(a)mathworks.com > Subject: RE: Mixed disk sizes within a single aggregate > > > When the stripes fill the equivalent of the smaller disks, wafl will > start striping only on the larger disks. This will cause performance > degradation due to "hot" disks. > > -----Original Message----- > From: owner-toasters(a)mathworks.com [mailto:owner-toasters@mathworks.com] > On Behalf Of David Knight > Sent: Thursday, September 21, 2006 9:44 AM > To: ggwalker(a)mindspring.com > Cc: Paul.Brosseau(a)netapp.com; jeff.mery(a)ni.com; toasters(a)mathworks.com > Subject: Re: Mixed disk sizes within a single aggregate > > > I think wafl stripes across all disks in an aggregate. > I'm not sure how it respond to having one raid group with larger disks - > likely it will not use part of them. I'm pretty sure netapp recommends all > disks in an aggregate be the same size, or, it will assume they are all > the size of the smallest disk. Of course, I could be wrong . . . > > > David > > >> Remember that WAFL still writes across the entire aggregate. Having a >> > >> slower RAID group in an aggregate of faster raid groups would be akin to >> having a slower disk in a RG of faster disks, would it not? >> >> >> >> Glenn >> >> >> >> >> ________________________________ >> >> >> From: owner-toasters(a)mathworks.com >> [mailto:owner-toasters@mathworks.com] >> On Behalf Of Brosseau, Paul >> Sent: Wednesday, September 20, 2006 8:05 PM >> To: Jeff Mery; toasters(a)mathworks.com >> Subject: RE: Mixed disk sizes within a single aggregate >> >> >> >> >> Mixing disk sizes in an aggregate is not a problem as long as you >> create RAID groups for each kind of disk. WAFL creates stripes at the > >> RAID group level. For best results create complete RAID groups each >> time you add disks to an aggregate. >> >> >> >> Paulb >> >> >> >> >> ________________________________ >> >> >> From: Jeff Mery [mailto:jeff.mery@ni.com] >> Sent: Wednesday, September 20, 2006 3:30 PM >> To: toasters(a)mathworks.com >> Subject: Mixed disk sizes within a single aggregate >> >> >> >> Greetings fellow toasters! >> <Background> >> We're looking at moving our 2 FAS940 systems from tradtional volumes >> to flexvols + aggregates. </Background> >> >> >> It would seem to me that the same rules and guidelines for creating >> traditional volumes now apply directly to the aggregate level (for the > >> most part). By rules and guidelines I mean things like trying not to >> mix disk sizes, try to avoid volumes (now aggregates?) that span FC >> adapters, etc. >> >> Are any of these things still a concern on modern versions of ONTAP >> (7+)? Does anyone have any best practices they'd be willing to share >> in regards to aggregate creation? NOW says "make them as big as possible >> using as many spindles as possible", but that doesn't really > help much. >> We use our filers for unstructured data only; cifs + nfs but no >> databases, no snapmirror, no snapvault, etc.. >> >> TIA, >> Jeff Mery - MCSE, MCP >> National Instruments >> >> >> ---------------------------------------------------------------------- >> -- >> - >> "Allow me to extol the virtues of the Net Fairy, and of all the >> fantastic dorks that make the nice packets go from here to there. Amen." >> TB - Penny Arcade >> ---------------------------------------------------------------------- >> -- >> - >> >> > > > > Confidentiality Notice: > This e-mail is intended only for the personal and confidential use of the > individual to whom it is addressed and may contain information that is > privileged, confidential and protected by law. If you are not the > intended recipient, you are hereby notified that any use or disclosure of > this information is strictly prohibited. If you have received this > message in error, please notify the sender immediately by reply e-mail > and delete the original message. Your compliance is appreciated. > > > >

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RE: Mixed disk sizes within a single aggregate
by Crawford, Mark (CBC) 22 Sep '06

22 Sep '06

When the stripes fill the equivalent of the smaller disks, wafl will start striping only on the larger disks. This will cause performance degradation due to "hot" disks. -----Original Message----- From: owner-toasters(a)mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of David Knight Sent: Thursday, September 21, 2006 9:44 AM To: ggwalker(a)mindspring.com Cc: Paul.Brosseau(a)netapp.com; jeff.mery(a)ni.com; toasters(a)mathworks.com Subject: Re: Mixed disk sizes within a single aggregate I think wafl stripes across all disks in an aggregate. I'm not sure how it respond to having one raid group with larger disks - likely it will not use part of them. I'm pretty sure netapp recommends all disks in an aggregate be the same size, or, it will assume they are all the size of the smallest disk. Of course, I could be wrong . . . David > Remember that WAFL still writes across the entire aggregate. Having a > slower RAID group in an aggregate of faster raid groups would be akin > to having a slower disk in a RG of faster disks, would it not? > > > > Glenn > > > > ________________________________ > > From: owner-toasters(a)mathworks.com > [mailto:owner-toasters@mathworks.com] > On Behalf Of Brosseau, Paul > Sent: Wednesday, September 20, 2006 8:05 PM > To: Jeff Mery; toasters(a)mathworks.com > Subject: RE: Mixed disk sizes within a single aggregate > > > > Mixing disk sizes in an aggregate is not a problem as long as you > create RAID groups for each kind of disk. WAFL creates stripes at the > RAID group level. For best results create complete RAID groups each > time you add disks to an aggregate. > > > > Paulb > > > > ________________________________ > > From: Jeff Mery [mailto:jeff.mery@ni.com] > Sent: Wednesday, September 20, 2006 3:30 PM > To: toasters(a)mathworks.com > Subject: Mixed disk sizes within a single aggregate > > > Greetings fellow toasters! > <Background> > We're looking at moving our 2 FAS940 systems from tradtional volumes > to flexvols + aggregates. > </Background> > > It would seem to me that the same rules and guidelines for creating > traditional volumes now apply directly to the aggregate level (for the > most part). By rules and guidelines I mean things like trying not to > mix disk sizes, try to avoid volumes (now aggregates?) that span FC > adapters, etc. > > Are any of these things still a concern on modern versions of ONTAP > (7+)? Does anyone have any best practices they'd be willing to share > in regards to aggregate creation? NOW says "make them as big as > possible using as many spindles as possible", but that doesn't really help much. > We use our filers for unstructured data only; cifs + nfs but no > databases, no snapmirror, no snapvault, etc.. > > TIA, > Jeff Mery - MCSE, MCP > National Instruments > > ---------------------------------------------------------------------- > -- > - > "Allow me to extol the virtues of the Net Fairy, and of all the > fantastic dorks that make the nice packets go from here to there. > Amen." > TB - Penny Arcade > ---------------------------------------------------------------------- > -- > - > Confidentiality Notice: This e-mail is intended only for the personal and confidential use of the individual to whom it is addressed and may contain information that is privileged, confidential and protected by law. If you are not the intended recipient, you are hereby notified that any use or disclosure of this information is strictly prohibited. If you have received this message in error, please notify the sender immediately by reply e-mail and delete the original message. Your compliance is appreciated.

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RE: Mixed disk sizes within a single aggregate
by Glenn Walker 22 Sep '06

22 Sep '06

Right. Pretty much all of this very long discussion centers on one concept: the old adage "as strong as the weakest link". Only in this case, it's as fast as the slowest link. Glenn -----Original Message----- From: maclean(a)cs.mcgill.ca [mailto:maclean@cs.mcgill.ca] Sent: Thursday, September 21, 2006 5:00 PM To: Stephen C. Losen Cc: maclean(a)cs.mcgill.ca; Glenn Walker; toasters(a)mathworks.com Subject: Re: Mixed disk sizes within a single aggregate > Actually Netapp told us it's not a problem to replace a slower drive > with a faster one. It's not good if you have a RG of fast drives to > replace one with a slower drive, because that drags down the whole RG. Yeah a read would have to wait for the slower disk to spin around to the proper block while all the faster disks have already provided the data. -Matthew

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RE: Mixed disk sizes within a single aggregate
by Glenn Walker 21 Sep '06

21 Sep '06

More FCAL adapters are better - spread the workload out as much as possible, but as Myles said, you're not going to see a workload go beyond the limit of a single adapter (typically). That said, if you have a large enough workload, you might see the head run out of resources before the FCAL loop does. When not using cluster, MPIO is a great way to go to help spread the load pretty evenly across adapters. Glenn -----Original Message----- From: owner-toasters(a)mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Myles Uyema Sent: Thursday, September 21, 2006 12:25 PM To: Jeff Mery Cc: David Knight; Glenn Walker; Paul.Brosseau(a)netapp.com; toasters(a)mathworks.com Subject: Re: Mixed disk sizes within a single aggregate Most workloads are not going to reach 2gbit fibrechannel saturation, except with the occasional disk reconstruction. With that in mind, you'll want to spread your raidgroups across as many loops as possible and within budget. Concerning different sized 10k rpm disks, just realize that since 144GB disks are larger than 72GB disks, you will eventually have more data on the 144GB raid group, so generally you will see more I/O toward that set of disks, but the RPM is the same, and the performance characteristics are basically identical. On Thu, 21 Sep 2006, Jeff Mery wrote: Thanks for the responses everyone. Just to confirm... ...WAFL does indeed stripe each flexvol across all disks in the aggregate. If you have a flexvol that's 5% of your total aggregate space, it's safe to conclude that it's using 5% of each disk in your aggregate (assuming aggregate disks are all the same size). This was the impression I got from the documentation and then confirmed by the group. ...We don't have any mixed performance disks in our system (everything is 10K RPM), just mixed sizes. Creating a separate RG for each disk size is a good idea; this prevents wasting any larger disks on parity for smaller ones. Thanks for the suggestion. It seems we still have some confusion around what happens with performance in this mixed-disk scenario as well as the impact of a single aggregate spanning multiple FC adapters. Can anyone from NetApp clarify these for us? Jeff Mery - MCSE, MCP National Instruments ------------------------------------------------------------------------ - "Allow me to extol the virtues of the Net Fairy, and of all the fantastic dorks that make the nice packets go from here to there. Amen." TB - Penny Arcade ------------------------------------------------------------------------ - David Knight <knight(a)atmos.albany.edu> 09/21/2006 08:43 AM To ggwalker(a)mindspring.com (Glenn Walker) cc Paul.Brosseau(a)netapp.com, jeff.mery(a)ni.com, toasters(a)mathworks.com Subject Re: Mixed disk sizes within a single aggregate I think wafl stripes across all disks in an aggregate. I'm not sure how it respond to having one raid group with larger disks - likely it will not use part of them. I'm pretty sure netapp recommends all disks in an aggregate be the same size, or, it will assume they are all the size of the smallest disk. Of course, I could be wrong . . . David > Remember that WAFL still writes across the entire aggregate. Having a > slower RAID group in an aggregate of faster raid groups would be akin to > having a slower disk in a RG of faster disks, would it not? > > > > Glenn > > > > ________________________________ > > From: owner-toasters(a)mathworks.com [mailto:owner-toasters@mathworks.com] > On Behalf Of Brosseau, Paul > Sent: Wednesday, September 20, 2006 8:05 PM > To: Jeff Mery; toasters(a)mathworks.com > Subject: RE: Mixed disk sizes within a single aggregate > > > > Mixing disk sizes in an aggregate is not a problem as long as you create > RAID groups for each kind of disk. WAFL creates stripes at the RAID > group level. For best results create complete RAID groups each time you > add disks to an aggregate. > > > > Paulb > > > > ________________________________ > > From: Jeff Mery [mailto:jeff.mery@ni.com] > Sent: Wednesday, September 20, 2006 3:30 PM > To: toasters(a)mathworks.com > Subject: Mixed disk sizes within a single aggregate > > > Greetings fellow toasters! > <Background> > We're looking at moving our 2 FAS940 systems from tradtional volumes to > flexvols + aggregates. > </Background> > > It would seem to me that the same rules and guidelines for creating > traditional volumes now apply directly to the aggregate level (for the > most part). By rules and guidelines I mean things like trying not to > mix disk sizes, try to avoid volumes (now aggregates?) that span FC > adapters, etc. > > Are any of these things still a concern on modern versions of ONTAP > (7+)? Does anyone have any best practices they'd be willing to share in > regards to aggregate creation? NOW says "make them as big as possible > using as many spindles as possible", but that doesn't really help much. > We use our filers for unstructured data only; cifs + nfs but no > databases, no snapmirror, no snapvault, etc.. > > TIA, > Jeff Mery - MCSE, MCP > National Instruments > > ------------------------------------------------------------------------ > - > "Allow me to extol the virtues of the Net Fairy, and of all the > fantastic > dorks that make the nice packets go from here to there. Amen." > TB - Penny Arcade > ------------------------------------------------------------------------ > - >

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