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 http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
