Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
If you choose the AOC-USAS-L8i controller route, don't worry too much about the exotic looking nature of these SAS/SATA controllers. These controllers drive SAS drives and also SATA drives. As you will be using SATA drives, you'll just get cables that plug into the card. The card has 2 ports. You buy a cable that plugs in to the port and fans out into 4 SATA connectors. Just buy 2 cables if you need to drive 8 drives, or at least more than 4. SuperMicro sell a few different cable lengths for these cables, so once you've measured, you can choose. Take a look at this post of mine and look for the card, cables and text where I also remarked on the scariness factor of dealing with 'exotic' hardware. http://breden.org.uk/2009/08/29/home-fileserver-mirrored-ssd-zfs-root-boot/ And cables are here: http://supermicro.com/products/accessories/index.cfm http://64.174.237.178/products/accessories/index.cfm (DNS failed so I gave IP address version too) Then select 'cables' from the list. From the cables listed, search for 'IPASS to 4 SATA Cable' and you will find they have a 23cm version (CBL-0118L-02) and a 50cm version (CBL-0097L-02). Sounds like your larger case will probably need the 50cm version. Cheers, Simon http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On 1/25/2010 6:23 PM, Simon Breden wrote: By mixing randomly purchased drives of unknown quality, people are taking unnecessary chances. But often, they refuse to see that, thinking that all drives are the same and they will all fail one day anyway... I would say, though, that buying different drives isn't inherently either random or drives of unknown quality. Most of the time, I know no reason other than price to prefer one major manufacturer to another. And, over and over again, I've heard of bad batches of drives. Small manufacturing or design or component sourcing errors. Given how the resilvering process can be quite long (on modern large drives) and quite stressful (when the system remains in production use during resilvering, so that load is on top of the normal load), I'd rather not have all my drives in the set be from the same bad batch! Google is working heavily with the philosophy that things WILL fail, so they plan for it, and have enough redundance to survive it -- and then save lots of money by not paying for premium components. I like that approach. -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On 1/27/2010 7:29 AM, Simon Breden wrote: And cables are here: http://supermicro.com/products/accessories/index.cfm http://64.174.237.178/products/accessories/index.cfm (DNS failed so I gave IP address version too) Then select 'cables' from the list. From the cables listed, search for 'IPASS to 4 SATA Cable' and you will find they have a 23cm version (CBL-0118L-02) and a 50cm version (CBL-0097L-02). Sounds like your larger case will probably need the 50cm version. And those seem to be half the price of the others I've found. I'll still have to check the length first, though. And they're listed on Amazon. (Supermicro either doesn't, or at least makes it very hard, to buy direct from their web site, or even check a price.) (This is a big Chenbro case, I think it's really a rack 4u system being used as a tower.) -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On Jan 27, 2010, at 12:34 PM, David Dyer-Bennet wrote: Google is working heavily with the philosophy that things WILL fail, so they plan for it, and have enough redundance to survive it -- and then save lots of money by not paying for premium components. I like that approach. Yes, it does work reasonably well. But many people on this forum complain that mirroring disks is too expensive, so they would never consider mirroring the whole box, let alone triple or quadruple mirroring the whole box :-) -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On Wed, Jan 27, 2010 at 02:34:29PM -0600, David Dyer-Bennet wrote: Google is working heavily with the philosophy that things WILL fail, so they plan for it, and have enough redundance to survive it -- and then save lots of money by not paying for premium components. I like that approach. So do I, and most other zfs fans. Google, unlike most of us, is also big enough to buy a whole pallet of disks at a time, and still spread them around to avoid common faults taking out all copies. -- Dan. pgpQ87YoZXEt0.pgp Description: PGP signature ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On 1/25/2010 6:23 PM, Simon Breden wrote: By mixing randomly purchased drives of unknown quality, people are taking unnecessary chances. But often, they refuse to see that, thinking that all drives are the same and they will all fail one day anyway... My use of the word random was a little joke to refer to drives that are bought without checking basic failure reports made by users, and then the purchaser later says 'oh no, these drives are c**p'. A little checking goes a long way IMO. But each to his own. I would say, though, that buying different drives isn't inherently either random or drives of unknown quality. Most of the time, I know no reason other than price to prefer one major manufacturer to another. Price is an important choice driver I think we all use. But the 'drives of unknown quality' bit is still possible to mitigate by checking, if one is willing to spend the time and knows where to look. We're never going to be 100% certain, but if I read widely of numerous reports that drives of a particular revision number are seriously substandard then I am going to take that info onboard to help me steer away from purchasing them. That's all. And, over and over again, I've heard of bad batches of drives. Small manufacturing or design or component sourcing errors. Given how the esilvering process can be quite long (on modern large drives) and quite stressful (when the system remains in production use during resilvering, so that load is on top of the normal load), I'd rather not have all my drives in the set be from the same bad batch! Indeed. This is why it's good to research, buy what you think is a good drive revision, then load your data onto them and test them out over a period of time. But one has to keep original data safely backed up. Google is working heavily with the philosophy that things WILL fail, so they plan for it, and have enough redundance to survive it -- and then save lots of money by not paying for premium components. I like that approach. Yep, as mentioned elsewhere, Google have enormous resources to be hugely redundant and safe. And yes, we all try to use our common sense to build in as much redundancy as we deem necessary and we are able to reasonably afford. And we have backups. Cheers, Simon http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
Okay, so this SuperMicro AOC-USAS-L8i is an SAS card? I've never done SAS; is it essentially a controller as flexible as SCSI that then talks to SATA disks out the back? Amazon seems to be the only obvious place to buy it (Newegg and Tiger Direct have nothing). And do I understand that it doesn't come with the cables it needs? And that what I need are SAS-to-4-SATA breakout cables? And that those m*f* b*ds cost $30 or so each and I'll need two of them? Bloody connector conspiracy. So I'd better open the system out and measure a bunch of things, because I need to make sure I can reach everything I need to reach (this is an oversize case, it's actually a 4u rackmount up on end, and it's full rack depth, so the distance from motherboard to drives can be significant). I'm up over $450 for a simple upgrade (that includes the 4x2.5-in-5.2-bay box, controller, 2x 7200rpm enterprise 2.5 drives, controller, cables, and a 2GB memory upgrade) at best-mainstream-retailer mailorder prices. The dratted drives are four times the size I need, too; nobody carries the 80GB enterprise models, which are only two times the size I need. The 160GB enterprise are only $7 each more expensive than the 80GB consumer models, though. Weird world.) -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On Tue, Jan 26, 2010 at 07:32:05PM -0800, David Dyer-Bennet wrote: Okay, so this SuperMicro AOC-USAS-L8i is an SAS card? I've never done SAS; is it essentially a controller as flexible as SCSI that then talks to SATA disks out the back? Yes, or SAS disks. Amazon seems to be the only obvious place to buy it (Newegg and Tiger Direct have nothing). And do I understand that it doesn't come with the cables it needs? Because the cables you need depend on what you have at the other end. And that what I need are SAS-to-4-SATA breakout cables? Likely, yes - and yes, measurinng would be a good idea. I'm up over $450 for a simple upgrade well, no. The simple upgrade would be a 2-port sata card to enable your extra two hotswap bays, like i suggested, plus the extra disks you already have. By all means go for extra and better, at corresponding cost, if you want. -- Dan. pgp4oHJFgAzB7.pgp Description: PGP signature ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On 1/26/2010 9:39 PM, Daniel Carosone wrote: On Tue, Jan 26, 2010 at 07:32:05PM -0800, David Dyer-Bennet wrote: Okay, so this SuperMicro AOC-USAS-L8i is an SAS card? I've never done SAS; is it essentially a controller as flexible as SCSI that then talks to SATA disks out the back? Yes, or SAS disks. Ah, so there's another level of complexity there. Okay, interesting. Well, I'm definitely not interested in spending more than SATA prices on disks, so I'll be going that mode. Amazon seems to be the only obvious place to buy it (Newegg and Tiger Direct have nothing). And do I understand that it doesn't come with the cables it needs? Because the cables you need depend on what you have at the other end. Right, since there are multiple possibilities I wasn't sure about. Makes reasonable sense, though I cringe at the cable prices (and I've spent 40 years in this industry; you'd think I'd be somewhat desensitized by now). And that what I need are SAS-to-4-SATA breakout cables? Likely, yes - and yes, measurinng would be a good idea. Glad I thought of it in time. I'm up over $450 for a simple upgrade well, no. The simple upgrade would be a 2-port sata card to enable your extra two hotswap bays, like i suggested, plus the extra disks you already have. By all means go for extra and better, at corresponding cost, if you want. Certainly there is a simpler option; although I don't think anybody actually suggested a good 2-port SATA card for Solaris. Do you have one in mind? Pci-e, I've even got an x16 slot free (and slower ones). (I haven't pulled the trigger on the order yet.) -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
Certainly there is a simpler option; although I don't think anybody actually suggested a good 2-port SATA card for Solaris. Do you have one in mind? Pci-e, I've even got an x16 slot free (and slower ones). (I haven't pulled the trigger on the order yet.) Hi, you could always get a sil3124 based card from Ebay. There are pci-e 1x cards available, 4 port card comes to about $50. At least the pci versions(~$40) work with OpenSolaris(tried one yesterday, though checked just whether the disks show up and I could make a zpool). Cheers, Olli -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
Hi David, I have the same motherboard and have been through this upgrade head-scratching before with my system, so hopefully I can give some useful tips. First of all, unless the situation has changed, forget trying to get the extra 2 SATA devices on the motherboard to work, as last time I looked, OpenSolaris had no JMicron JMB363 driver. So, unless you add an extra SATA card, you'll be limited to using the existing 6 SATA ports. There are also 2 EIDE ports you could use for your mirrored boot drives, but from what you say, it sounds like you have SATA devices for your two mirrored boot drives. So like you say, if you don't add a new SATA controller card then you will have to replace each existing half of your 2 mirrors and resilver, which leaves your current 2-way mirrors a little vulnerable, although not too vulnerable, as you'll have removed a working drive from a working mirror presumably. So that is the mirror upgrade process. Another possibility is to do what I did and add a SATA controller card. For this motherboard, to avoid restricting yourself too much, you might be better going for a PCIe-based 8-port SATA card, and the best I found is the SuperMicro AOC-USAS-L8i card, which is reasonably priced. Using this card, you could move your existing mirrors to the card, then add your new larger disks to each of the mirrors to grow your pool, or just move the mirrors as they are, and add new drives as additional mirrors to your pool. Depending on your case space available, your choice might be dictated by the space available. Anyway hope this helps. Last thing, you could create a RAID-Z2 vdev with all those new drives, giving double-parity -- i.e. your data still survives even if any 2 drives die. With 2-way mirrors, you lose all your data if 2 drives die in any of your mirrors. So another option could be to use 3-way mirrors with all of your new drives. So many options... :) Cheers, Simon http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On Mon, January 25, 2010 13:11, Simon Breden wrote: I have the same motherboard and have been through this upgrade head-scratching before with my system, so hopefully I can give some useful tips. Great! Thanks. First of all, unless the situation has changed, forget trying to get the extra 2 SATA devices on the motherboard to work, as last time I looked, OpenSolaris had no JMicron JMB363 driver. I hadn't found anything, so this isn't totally a surprise. I thought it was worth asking explicitly, in case somebody else was a better driver-hunter than me. So, unless you add an extra SATA card, you'll be limited to using the existing 6 SATA ports. There are also 2 EIDE ports you could use for your mirrored boot drives, but from what you say, it sounds like you have SATA devices for your two mirrored boot drives. One of those EIDE ports is running the optical drive, so I don't actually have two free ports there even if I replaced the two boot drives with IDE drives. I've given some though to booting from a thumb drive instead of disks. That would free up two SATA ports AND two hot-swap disk bays, which would be nice. And by simply keeping an image of the thumb drive contents, I could replace it very quickly if something died in it, so I could live without automatic failover redundancy in the boot disks. Obviously thumb drives are slow, but other than boot time, it should slow down anything important too much (especially if I increase memory). So like you say, if you don't add a new SATA controller card then you will have to replace each existing half of your 2 mirrors and resilver, which leaves your current 2-way mirrors a little vulnerable, although not too vulnerable, as you'll have removed a working drive from a working mirror presumably. So that is the mirror upgrade process. Yep, that's the simplest plan. Another possibility is to do what I did and add a SATA controller card. For this motherboard, to avoid restricting yourself too much, you might be better going for a PCIe-based 8-port SATA card, and the best I found is the SuperMicro AOC-USAS-L8i card, which is reasonably priced. My current chassis has 8 hot-swap bays, so unless I change that, nothing I can do will consume more than two additional controller ports. Seems like a two-port card would be cheaper than an 8-port card (although as you say that 8-port card isn't that bad, around $150 last I looked it up). But does anybody have a good 2-port card to recommend that's significantly cheaper? If there is none, then future flexibility does start to look interesting. Using this card, you could move your existing mirrors to the card, then add your new larger disks to each of the mirrors to grow your pool, or just move the mirrors as they are, and add new drives as additional mirrors to your pool. Depending on your case space available, your choice might be dictated by the space available. Case space is definitely the limit. However, 6 drives worth of data pool is a great plenty for a home server IMHO. (Since video, if we start recording it, will go elsewhere.) Anyway hope this helps. Definitely, both as to detailed information, and as to things to think more about. Last thing, you could create a RAID-Z2 vdev with all those new drives, giving double-parity -- i.e. your data still survives even if any 2 drives die. With 2-way mirrors, you lose all your data if 2 drives die in any of your mirrors. So another option could be to use 3-way mirrors with all of your new drives. So many options... :) I could have had more space initially by using the 4 disks in RAIDZ instead of two mirror pairs. I decided not to because that left me only very bad expansion options -- replacing all 4 drives at once and risking other drives failing during resilver 4 times in a row (and the removed drive isn't much use in recovery in that scenario I don't think). Whereas with the mirror pairs I run much less risk of errors during resilver simply based on less time, two disks vs. four disks. I actually started with just one mirror pair, and then added a second mirror vdev to the pool when the first one started to get full. I basically settled on mirror pairs as my building blocks for this fileserver. My initial selection of an 8-bay hot-swap chassis essentially set the terms of much of the rest of the decision-making (well, that plus the decision to put the boot disks in hot-swap as well; after all, if one of them dies, I'm as dead as if a data disk dies if there's no redundancy). http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ Ooh, looks like there's lots of interesting detail there, too. -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
One of those EIDE ports is running the optical drive, so I don't actually have two free ports there even if I replaced the two boot drives with IDE drives. Yep, as I expected. I've given some though to booting from a thumb drive instead of disks. That would free up two SATA ports AND two hot-swap disk bays, which would be nice. And by simply keeping an image of the thumb drive contents, I could replace it very quickly if something died in it, so I could live without automatic failover redundancy in the boot disks. Obviously thumb drives are slow, but other than boot time, it should slow down anything important too much (especially if I increase memory). I've seen anecdotal evidence for not using thumb drives, speed, error-prone, logging etc, but maybe someone else can provide some more info. If you have a 5.25 or 3.5 slot outside of your 8-drive drive cage, you could use two 2.5 HDs as a boot mirror, leaving all 8 bays free for drives for future expansion needs, as a possibility. But if six data drives are enough then this becomes less interesting. An possible option though. I chucked 2 SSDs into one 5.25 slot for my boot mirror, which worked out nicely, and a cheaper option is to use 2.5 HDs instead -- with a twin mounter here: http://breden.org.uk/2009/08/29/home-fileserver-mirrored-ssd-zfs-root-boot/ My current chassis has 8 hot-swap bays, so unless I change that, nothing I can do will consume more than two additional controller ports. Seems like a two-port card would be cheaper than an 8-port card (although as you say that 8-port card isn't that bad, around $150 last I looked it up). But does anybody have a good 2-port card to recommend that's significantly cheaper? If there is none, then future flexibility does start to look interesting. Maybe others can recommend a 2 or 4 port card. When I looked mid-2009 I found some card but I didn't really feel like the hardware or possibly the driver was that robust, and I prefer not to lose my data or get more grey hairs/headaches... so I chose the 8-port known robust card/driver option :) And you just know that you'll need that extra port or two one day... I could have had more space initially by using the 4 disks in RAIDZ instead of two mirror pairs. I decided not to because that left me only very bad expansion options -- replacing all 4 drives at once and risking other drives failing during resilver 4 times in a row (and the removed drive isn't much use in recovery in that scenario I don't think). Whereas with the mirror pairs I run much less risk of errors during resilver simply based on less time, two disks vs. four disks. I actually started ith just one mirror pair, and then added a second mirror vdev to the pool when the first one started to get full. I basically settled on mirror pairs as my building blocks for this fileserver. Indeed, mirrors have a lot of interesting properties. But if you're upgrading now, you might want to consider using 3 way mirrors instead of 2 as this gives extra protection. Ooh, looks like there's lots of interesting detail there, too. Yes, I documented most of my ZFS discoveries there so others can hopefully benefit from my headaches :) Cheers, Simon http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On Mon, January 25, 2010 14:11, Simon Breden wrote: I've given some though to booting from a thumb drive instead of disks. That would free up two SATA ports AND two hot-swap disk bays, which would be nice. And by simply keeping an image of the thumb drive contents, I could replace it very quickly if something died in it, so I could live without automatic failover redundancy in the boot disks. Obviously thumb drives are slow, but other than boot time, it should slow down anything important too much (especially if I increase memory). I've seen anecdotal evidence for not using thumb drives, speed, error-prone, logging etc, but maybe someone else can provide some more info. If you have a 5.25 or 3.5 slot outside of your 8-drive drive cage, you could use two 2.5 HDs as a boot mirror, leaving all 8 bays free for drives for future expansion needs, as a possibility. But if six data drives are enough then this becomes less interesting. An possible option though. I chucked 2 SSDs into one 5.25 slot for my boot mirror, which worked out nicely, and a cheaper option is to use 2.5 HDs instead -- with a twin mounter here: http://breden.org.uk/2009/08/29/home-fileserver-mirrored-ssd-zfs-root-boot/ I've got at least one available 5.25 bay. I hadn't considered 2.5 HDs; that's a tempting way to get the physical space I need. I'm running an SSD boot disk in my desktop box and so far I'm very disappointed (about half a generation too early, is my analysis). And I don't need the theoretical performance for this boot disk. I don't see the expense as buying me anything, and they're still pretty darned expensive. I've considered having the boot disks not hot-swap. I could live with that, although getting into the case is a pain (it lives on a shelf over my desk, so I either work on it in place or else I disconnect and reconnect all the external cabling; either way is ugly). Logging to flash-drives is slow, yes, and will wear them out, yes. But if a $40 drive lasts two years, I'm very happy. And the demise is write-based in this scenario, not random failure, so it should be fairly predictable. But does anybody have a good 2-port card to recommend that's significantly cheaper? If there is none, then future flexibility does start to look interesting. Maybe others can recommend a 2 or 4 port card. When I looked mid-2009 I found some card but I didn't really feel like the hardware or possibly the driver was that robust, and I prefer not to lose my data or get more grey hairs/headaches... so I chose the 8-port known robust card/driver option :) And you just know that you'll need that extra port or two one day... I'm trying to simplify here! But yeah, if nobody comes along with a significantly cheaper robust card of fewer ports, I'll probably do the same. Indeed, mirrors have a lot of interesting properties. But if you're upgrading now, you might want to consider using 3 way mirrors instead of 2 as this gives extra protection. 6 or 8 hot-swap bays and enough controllers gives me relatively few interesting choices. 6: 2 three-way, or three two-way; 8: four two-way, or...still only 2 three-way. I don't think double redundancy is worth much to me in this case (daily backups to two or more external media sets, and hot-swap so I don't wait to replace a bad drive). Actually, if I move the boot disks somewhere and have 8 hot-swap bays for data, I might well go with three two-way mirrors plus two hot spares. Or at least one. -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
I've got at least one available 5.25 bay. I hadn't considered 2.5 HDs; that's a tempting way to get the physical space I need. Yes, it is an interesting option. But remember about any necessary cooling if moving them from a currently cooled area. As I used SSDs this turned out to be irrelevant as they don't seem to get hot, but for mechanical drives this is not the case. I'm running an SSD boot disk in my desktop box and so far I'm very disappointed (about half a generation too early, is my analysis). And I don't need the theoretical performance for this boot disk. I don't see the expense as buying me anything, and they're still pretty darned expensive. Which model/capacity are you using? Yes, they are not quite there yet, and I certainly should probably not have bothered buying these ones from the price perspective, as two 2.5 drives would have been fine. But for a desktop machine I'm quite surprised you're disappointed. But there is currently enormous variation in quality due to firmware making huge differences. They can only improve :) I've considered having the boot disks not hot-swap. I could live with hat, although getting into the case is a pain (it lives on a shelf over my desk, so I either work on it in place or else I disconnect and reconnect all the external cabling; either way is ugly). I think I would be tempted to maximise the available hot-swap bay space for data drives -- but only if it's required. Logging to flash-drives is slow, yes, and will wear them out, yes. But if a $40 drive lasts two years, I'm very happy. And the demise is write-based in this scenario, not random failure, so it should be fairly predictable. Not an expert on this but I seem to remember that constant log-writing wore out these thumbdrives out, but don't quote me on that. 2.5 drives are very cheap too, and would be my personal choice in this case. I'm trying to simplify here! But yeah, if nobody comes along with a significantly cheaper robust card of fewer ports, I'll probably do the same. If you find the extra ports capacity upgrade options useful then you won't go wrong with that card. It's worked flawlessly for me. Along with the 8-ports on the card, you have the 6 additional ones remaining on the mobo, so lack of SATA ports will never be a problem again :) It gives you lots of space to juggle things around if you want to. One example, if one has a large case, is to make a backup pool from old drives within the same case. I haven't done this, but it has crossed my mind. As all the drives are local, the backup speed should be terrific, as there's no network involved... and if the drives were on a second PSU, which is only switched on to perform backups, no electricity needs to be wasted. I have to look into whether this is a workable idea though... 6 or 8 hot-swap bays and enough controllers gives me relatively few interesting choices. 6: 2 three-way, or three two-way; 8: four two-way, or...still only 2 three-way. I don't think double redundancy is worth much to me in this case (daily backups to two or more external media sets, and hot-swap so I don't wait to replace a bad drive). Indeed, and often forgotten by home builders, is that if you have dependable regular backups which employ redundancy in the backup pool, then you don't need to be so paranoid about your main storage pool, although I personally prefer to have double parity. Extra insurance is a good thing :) Actually, if I move the boot disks somewhere and have 8 hot-swap bays for data, I might well go with three two-way mirrors plus two hot spares. Or at least one. Yep, it gives you a lot of options :) Cheers, Simon http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
Some other points and recommendations to consider: - Since you have the bays, get the controller to drive them, regardless. They will have many uses, some of which below. A 4-port controller would allow you enough ports for both the two empty hotswap bays, plus the dual 2.5 carrier. Note there are 4-in-1 5.25 versions of those, too. - Don't be afraid to dike out the optical drive, either for case space or available ports. Almost anything else is a better tradeoff: CF to ATA, or ATA laptop disks, can fit anywhere in the case as rpool. USB sticks are fine (even preferable) for intalls, and it sounds like the drive is located awkwardly for use as a burner anyway. Put the drive in an external USB case if you want, or leave it in the case connected via a USB bridge internally. - If you decide to mirror with bigger drives (even if next time around, rather than immediately), you can reduce the risk of the single failure since you have extra bays: attach the first bigger disk as a third mirror, then replace the second disk with a bigger one, then remove the last smaller one. Keep a free slot for this. - Since you have 7x 400, you might as well use them. Stick with your mirrors, adding a third set plus a hotspare. Or, if you can be bothered spending the time to rearrange, raidz2 for some extra space (defer the next upgrade longer, keep more snapshots until then). - 7x 400 will make good rolling backup media, too, in your spare hotswap bay(s). - I've had mixed results from thumb drives, including corruption. You can always mirror those, too; I consider it mandatory if booting. Beware that moving them to different usb ports can currently cause boot failures. Device selection seems to be important, but there's little way to know beforehand. -- Dan. pgpfmJAdqABvx.pgp Description: PGP signature ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On Mon, January 25, 2010 15:26, Simon Breden wrote: I've got at least one available 5.25 bay. I hadn't considered 2.5 HDs; that's a tempting way to get the physical space I need. Yes, it is an interesting option. But remember about any necessary cooling if moving them from a currently cooled area. As I used SSDs this turned out to be irrelevant as they don't seem to get hot, but for mechanical drives this is not the case. Well, they'll be in a space designated as a drive bay, so it should have some airflow. I'll certainly check. I'm running an SSD boot disk in my desktop box and so far I'm very disappointed (about half a generation too early, is my analysis). And I don't need the theoretical performance for this boot disk. I don't see the expense as buying me anything, and they're still pretty darned expensive. Which model/capacity are you using? Yes, they are not quite there yet, and I certainly should probably not have bothered buying these ones from the price perspective, as two 2.5 drives would have been fine. But for a desktop machine I'm quite surprised you're disappointed. But there is currently enormous variation in quality due to firmware making huge differences. They can only improve :) It's an OCZ Core II, I believe. I've got an Intel -M waiting to replace it when I can find time (probably when I install Windows 7). I've considered having the boot disks not hot-swap. I could live with hat, although getting into the case is a pain (it lives on a shelf over my desk, so I either work on it in place or else I disconnect and reconnect all the external cabling; either way is ugly). I think I would be tempted to maximise the available hot-swap bay space for data drives -- but only if it's required. I'm currently running 400GB drives. So I could 5x my space just by upgrading to modern drives. I'm really not short on space! What's it cost to run a drive for a year again? Maybe I really should just replace one existing pool with larger drives and let it go at that, rather than running two more drives. The spare bays I have are exposed, so I can replace my two boot drives with 2.5 drives in hot-swap bays. There are some 4x2.5 hot-swap in 5.25 bay products out there, not even that expensive. Then I'd have 12 drives available, and if I get the 8-port controller, 14 controller ports. I can use the 8 3.5 bays for data disks (alternating the two controllers), use two of the 2.5 bays for boot disks (again alternating controllers), and have two slots left for hypothetical future SSD L2ARC or something :-). The 6 ports on the motherboard run exactly half of the 12 bays, 6 of the ports on the add-in-card run the other half of the 12 bays, and 2 ports on the add-in card go to waste, so every mirror pair can be split across controllers. Logging to flash-drives is slow, yes, and will wear them out, yes. But if a $40 drive lasts two years, I'm very happy. And the demise is write-based in this scenario, not random failure, so it should be fairly predictable. Not an expert on this but I seem to remember that constant log-writing wore out these thumbdrives out, but don't quote me on that. 2.5 drives are very cheap too, and would be my personal choice in this case. 2.5 drives seem to bottom out at $50 (I've seen $45, nothing lower). And the smallest I can find are 2x the size I need :-). One example, if one has a large case, is to make a backup pool from old drives within the same case. I haven't done this, but it has crossed my mind. As all the drives are local, the backup speed should be terrific, as there's no network involved... and if the drives were on a second PSU, which is only switched on to perform backups, no electricity needs to be wasted. I have to look into whether this is a workable idea though... The case is huge, but most of the space is already taken up with the two sets of 4 hot-swap bays. Wouldn't be putting my backup pool internally anyway, though. The important thing about the backup pool is that it gets taken off-site regularly. I'll probably add a third backup drive, and a bigger one. (Single-file recovery is from snapshots on the main data pool, rather than from backups.) Also harder to grab the whole case and run with it in event of fire, or put it in a local fire safe, etc. 6 or 8 hot-swap bays and enough controllers gives me relatively few interesting choices. 6: 2 three-way, or three two-way; 8: four two-way, or...still only 2 three-way. I don't think double redundancy is worth much to me in this case (daily backups to two or more external media sets, and hot-swap so I don't wait to replace a bad drive). Indeed, and often forgotten by home builders, is that if you have dependable regular backups which employ redundancy in the backup pool, then you don't need to be so paranoid about your main storage pool, although I personally prefer to have double parity. Extra insurance is a good thing :)
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On Mon, January 25, 2010 15:44, Daniel Carosone wrote: Some other points and recommendations to consider: - Since you have the bays, get the controller to drive them, regardless. They will have many uses, some of which below. A 4-port controller would allow you enough ports for both the two empty hotswap bays, plus the dual 2.5 carrier. Note there are 4-in-1 5.25 versions of those, too. Yes, I found the 4-in-1. If my spare space is 5.25 I'll probably go with the 4x on general principles (prices aren't so different). Or because, as an American, I'm required to automatically consider more to be better :-). - Don't be afraid to dike out the optical drive, either for case space or available ports. Almost anything else is a better tradeoff: CF to ATA, or ATA laptop disks, can fit anywhere in the case as rpool. USB sticks are fine (even preferable) for intalls, and it sounds like the drive is located awkwardly for use as a burner anyway. Put the drive in an external USB case if you want, or leave it in the case connected via a USB bridge internally. It's for installs and rescues, mostly, which I still find more convenient on DVD. - If you decide to mirror with bigger drives (even if next time around, rather than immediately), you can reduce the risk of the single failure since you have extra bays: attach the first bigger disk as a third mirror, then replace the second disk with a bigger one, then remove the last smaller one. Keep a free slot for this. In future, when I have extra bays, definitely. In fact, without extra bays, I should probably connect a spare USB drive of suitable size as an extra mirror during the upgrade. It won't help performance, but it will help safety. - Since you have 7x 400, you might as well use them. Stick with your mirrors, adding a third set plus a hotspare. Or, if you can be bothered spending the time to rearrange, raidz2 for some extra space (defer the next upgrade longer, keep more snapshots until then). I'm nearly certain to start with adding a third 2x400 mirror. The only issue is two more drives spinning (and no way to ever reduce that; until pool shrinking is implemented anyway). I see RAIDZ as a losing proposition for me. In an 8-bay box, the options are 2 4-disk RAIDZ2 sets, which is 50% available space like a mirror but requires me to upgrade in sets of 4 drives, and exposes me to errors during resilver in the 4 drive replacements; or else an 8-drive RAIDZ2, which does give me better available space, but now requires me to replace in sets of *8* drives and be vulnerable through *8* resilver operations. I don't like either option. - 7x 400 will make good rolling backup media, too, in your spare hotswap bay(s). At some point I'll probably go to some sort of external disk box for multi-drive backup. So far I'm committed to single-drive backup. (Current drives are 1TB, current pool is 800GB.) - I've had mixed results from thumb drives, including corruption. You can always mirror those, too; I consider it mandatory if booting. Beware that moving them to different usb ports can currently cause boot failures. Device selection seems to be important, but there's little way to know beforehand. My backup scripts are a bit at risk from weird USB port issues with disk naming as well. However, the namespace doesn't seem to have any possibility of overlapping the names of the disks in hot-swap SATA enclosures, so it can't overwrite any of them by any mechanism I can find. -- David Dyer-Bennet, d...@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
Well, they'll be in a space designated as a drive bay, so it should have some airflow. I'll certainly check. Yes, it's certainly worth checking. It's an OCZ Core II, I believe. I've got an Intel -M waiting to replace it when I can find time (probably when I install Windows 7). AFAIK the Intel ones should be good as they do serious amounts of testing and have huge RD to develop great drives. To cut it short, another idea is to: 1. build another box to make a new NAS using cheaper higher capacity drives 2. zfs send/recv the pool contents to the new NAS 3. use the old box as a backup machine containing as many old drives as you've got in a RAID-Z1 or RAID-Z2 vdev(s) so that you make efficient use of the capacity available in these 400GB drives. Cheers, Simon http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
On Mon, Jan 25, 2010 at 04:08:04PM -0600, David Dyer-Bennet wrote: - Don't be afraid to dike out the optical drive, either for case space or available ports. [..] [..] Put the drive in an external USB case if you want, or leave it in the case connected via a USB bridge internally. It's for installs and rescues, mostly, which I still find more convenient on DVD. Yeah, me too sometimes - but they're just as good with the DVD connected via USB, while the freed up controller ports (and drive bay, if relevant) may offer additional convenience - like not needing to buy an extra controller yet. I'm nearly certain to start with adding a third 2x400 mirror. The only issue is two more drives spinning (and no way to ever reduce that; until pool shrinking is implemented anyway). Not strictly true, especially if your replacement disks are at least twice the size of your originals (which is easy for 400's :-). You can use partitions or files on the larger disks, if shrinking is still not there yet at that future time. Ugly, sure, but it is a counterexample for no way to ever. :-) I see RAIDZ as a losing proposition for me. In an 8-bay box, the options are 2 4-disk RAIDZ2 sets, which is 50% available space like a mirror but requires me to upgrade in sets of 4 drives, and exposes me to errors during resilver in the 4 drive replacements; or else an 8-drive RAIDZ2, which does give me better available space, but now requires me to replace in sets of *8* drives and be vulnerable through *8* resilver operations. I don't like either option. Fair enough. Note that the vulnerable window is still a vulnerability to two extra failures - the second parity, plus the original data. There's always raidz3 :-) I got over the reluctance to do drive replacements in larger batches quite some time ago (well before there was zfs), though I can certainly sympathise. For me, drives bought incrementally never matched up (vendors change specs too often, especially for consumer units) and the previous matched set is still a useful matched backup set. My backup scripts are a bit at risk from weird USB port issues with disk naming as well. However, the namespace doesn't seem to have any possibility of overlapping the names of the disks in hot-swap SATA enclosures, so it can't overwrite any of them by any mechanism I can find. That's not really the issue I was referring to, though it's another risk. I was referring to the fact that the rpool may not import at boot time, with the usb stick in other than the slot it was originally created. I filed a bug for this ages ago, but can't find it right now. -- Dan. pgpG6GnWiMi2Q.pgp Description: PGP signature ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Going from 6 to 8 disks on ASUS M2N-SLI Deluxe motherboa
I got over the reluctance to do drive replacements in larger batches quite some time ago (well before there was zfs), though I can certainly sympathise. Yep, it's not so much of a big deal. One has to think a moment to see what is needed, check out any possible gotchas in order to carry out the upgrade safely, and then go ahead and do the upgrade. For me, drives bought incrementally never matched up (vendors change specs too often, especially for consumer units) and the previous matched set is still a useful matched backup set. I agree, better to research good drives, as far as is reasonably possible, and then buy a batch of them. Test them out for a period, and always keep your old data. And backups. By mixing randomly purchased drives of unknown quality, people are taking unnecessary chances. But often, they refuse to see that, thinking that all drives are the same and they will all fail one day anyway... Cheers, Simon http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
