Re: Software or hardware RAID1. (gstripe)
On Sat, 28 Aug 2004 20:39:36 +, Thordur I. [EMAIL PROTECTED] wrote: I think I will go for a hardware raid controler (RAID5 sounds good, but my budget doesn´t really allow me to buy 2x new disks ;). Well, I would say... postpond your RAID for a few weeks and gather the money to buy the disks. On a mission critical system, a RAID -5 is really worth in both stability, performance and fault tolerance. Btw. What hardware raid controlers (sata) do you listmembers recommend ? There are very few things which really dont work under FreeBSD. Just some work out of the box and some needs a little attention like a misbehaved kid. The fact is, the more bucks you throw in, the better facilities u get. I have read some positive things about the 3ware 9xxx and 8xxx series (a thread on -stable) Yeh, they work almost out of the box without any requirement for tweaking. -- Subhro Sankha Kar School of Information Technology Block AQ-13/1 Sector V ZIP 700091 India ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Software or hardware RAID1. (gstripe)
Subhro wrote: On Sat, 28 Aug 2004 20:39:36 +, Thordur I. [EMAIL PROTECTED] wrote: I think I will go for a hardware raid controler (RAID5 sounds good, but my budget doesn´t really allow me to buy 2x new disks ;). Well, I would say... postpond your RAID for a few weeks and gather the money to buy the disks. On a mission critical system, a RAID -5 is really worth in both stability, performance and fault tolerance. Btw. What hardware raid controlers (sata) do you listmembers recommend ? There are very few things which really dont work under FreeBSD. Just some work out of the box and some needs a little attention like a misbehaved kid. The fact is, the more bucks you throw in, the better facilities u get. I have read some positive things about the 3ware 9xxx and 8xxx series (a thread on -stable) Yeh, they work almost out of the box without any requirement for tweaking. Actually, my situation is not mission-critcal, still in a way it is. I have decided to go for a RAID5 controler (3ware 9) and simple wait a few weeks until I have gatherd the funds :) When you say almost out of the box what do you mean ? I think I´m right when I say that there are drivers ready for the 3ware cards so I do not see why there are any proplems besides overstepping the learning curve. Anyway I think you and the other listmembers again for there input. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Software or hardware RAID1. (gstripe)
On Sun, 29 Aug 2004 12:45:44 +, Thordur I. [EMAIL PROTECTED] wrote: Subhro wrote: On Sat, 28 Aug 2004 20:39:36 +, Thordur I. [EMAIL PROTECTED] wrote: I think I will go for a hardware raid controler (RAID5 sounds good, but my budget doesn´t really allow me to buy 2x new disks ;). Well, I would say... postpond your RAID for a few weeks and gather the money to buy the disks. On a mission critical system, a RAID -5 is really worth in both stability, performance and fault tolerance. Btw. What hardware raid controlers (sata) do you listmembers recommend ? There are very few things which really dont work under FreeBSD. Just some work out of the box and some needs a little attention like a misbehaved kid. The fact is, the more bucks you throw in, the better facilities u get. I have read some positive things about the 3ware 9xxx and 8xxx series (a thread on -stable) Yeh, they work almost out of the box without any requirement for tweaking. Actually, my situation is not mission-critcal, still in a way it is. I have decided to go for a RAID5 controler (3ware 9) and simple wait a few weeks until I have gatherd the funds :) i have used the 3ware cards in various production environments and have a comments. They seem to work pretty well in a RAID5 config, altho I would not suggest using them in a stripe. The cache on the controller is just too small. You may see some negative impacts of the small cache in a RAID5 config under heavy I/O loads but with RAID5 slower I/O performance is to be expected. I believe the Adaptec IDE cards have a larger cache on the board, altho I'm not %100 on this. On the bright side the 3ware cards are pretty common and the twe driver seems rock solid on 4.x. I have not had a chance to play with the 9 cards so I do not know how stable the driver for that device is. When you say almost out of the box what do you mean ? I think I´m right when I say that there are drivers ready for the 3ware cards so I do not see why there are any proplems besides overstepping the learning curve. In my experience if you have the driver enabled in your kernel (twe for the older 3ware cards) then the disk devices should be recognized. You actually build/configure the RAID's on the cards firmware before you load the OS, so there should not be *too* much to do w/in FreeBSD itself. Anyway I think you and the other listmembers again for there input. have fun! -p ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] -- ~~o0OO0o~~ Pete Wright www.nycbug.org NYC's *BSD User Group ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Software or hardware RAID1. (gstripe)
First to thank for the replys. They have been very helpful. Second, s/gstripe/gmirror I was reading the gstripe man page just minutes before I wrote the email ;) I think I will go for a hardware raid controler (RAID5 sounds good, but my budget doesn´t really allow me to buy 2x new disks ;). Btw. What hardware raid controlers (sata) do you listmembers recommend ? I have read some positive things about the 3ware 9xxx and 8xxx series (a thread on -stable) I think I will go for that one. Any comments on the command-to-stuff thing wich the 3ware card have (what is it called ?) Anyhow, this has been very helpful I wish to thank you again. With kind regards, Thordur I. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Software or hardware RAID1. (gstripe)
I´m currently trying to decide upon a sultion on how to go about keepin my data safe. Now, a RAID1 setup sounds good in this position. But I can´t seem to find an answer to one question. Let´s say that I have 2x 120Gb (ad1 and ad2) disk. I stripe them wich should give something like /dev/stripe/foo (either with gstripe or a hardware raid controler.) Now I fill this striped volume with data, and ad1 dies. What happen´s ? Does gstripe alert my that ad1 has died and will I still be able to access /dev/stripe/foo ? And when I shut the box down, remove ad1 and insert another (identical disk) to restore the stripe, what then ? (assume the same bus ofcourse) I have tryed to google this up but to no avail. Any help is well appriceated. With kind regards, Thordur I. PS: CC my for I´m not on the list. (Btw, do list members consider this a bother for if so I would just subscripe to the list (currently though I´m supscried to what I think are to many lists :)) ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Software or hardware RAID1. (gstripe)
On Fri, 27 Aug 2004 21:40:22 +, Thordur I. [EMAIL PROTECTED] wrote: I´m currently trying to decide upon a sultion on how to go about keepin my data safe. RAID 5 is your best bet. RAID 1 Just ensures mirroring. While RAID 5 can actually rebuild volumes. Let´s say that I have 2x 120Gb (ad1 and ad2) disk. I stripe them wich should give something like /dev/stripe/foo (either with gstripe or a hardware raid controler.) You get that strip device only if you use a softwre RAID. If you ues a RAID controller card, the whole RAID is completely transparent to the OS. Now I fill this striped volume with data, and ad1 dies. What happen´s ? Does gstripe alert my that ad1 has died and will I still be able to access /dev/stripe/foo ? You don't need to care about the striping, as both the Disks are exact clones of each other. So you can simply pull out the healthy disk and start using it as a single drive OR you can push in another healthy disk to replace the dead one and rebuild the volume. However if you are using a RAID controller card, the hardware would do the rebuilding for you. Refer to the Vinum volume manager section of the handbook. PS: CC my for I´m not on the list. (Btw, do list members consider this a bother for if so I would just subscripe to the list (currently though I´m supscried to what I think are to many lists :)) This is an open list so anyone may subscribe. BTW I personally feel its worthwhile to subscribe even if you dont want or not capable to asnwer questions because you can learn from others problems and save hours of troubleshoting later. You can also live with a scalp full of hair :-). Regards S. -- Subhro Sankha Kar School of Information Technology Block AQ-13/1 Sector V ZIP 700091 India ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Software or hardware RAID1. (gstripe)
On Fri, 27 Aug 2004 21:40:22 +, Thordur I. [EMAIL PROTECTED] wrote: I´m currently trying to decide upon a sultion on how to go about keepin my data safe. Now, a RAID1 setup sounds good in this position. But I can´t seem to find an answer to one question. Let´s say that I have 2x 120Gb (ad1 and ad2) disk. I stripe them wich should give something like /dev/stripe/foo (either with gstripe or a hardware raid controler.) Now I fill this striped volume with data, and ad1 dies. What happen´s ? Does gstripe alert my that ad1 has died and will I still be able to access /dev/stripe/foo ? And when I shut the box down, remove ad1 and insert another (identical disk) to restore the stripe, what then ? (assume the same bus ofcourse) I have tryed to google this up but to no avail. Any help is well appriceated. here is a good link regarding raid levels in general http://www.acnc.com/04_01_00.html what it sounds like is you want to create a mirror of disks for maximum data integrity. depending on how much disk i/o you are going to be doing i think using a hardware RAID solution on one level or another is probably the best choice. not only does it free the OS up from having to manage the RAID but you also gain benefits of onboard cache of the disk controllers, and if you are lucky decent management firmware to maintain the array(add new disks, verification, etc). the idea with striping is to be able to survive a failure of one of the disks while being reasonably sure that the data integrity on those disks will be intact. most hardware raid controllers will alert you when a disk fails, as i'm sure gstripe will as well altho i have not used it personally. the next step is rebuilding, this is usually also managed by the hardware controller or via the RAID implementation on the OS level (vinum etc..) and should be automatic when a new working disk is available. If you are lucky to have hot-swapable disks a power cycle is not even neccessary. now if you have the money/space for multiple disks you it may worth looking at RAID 5, which will give you decent i/o and decent fault tolerance. or you can start playing with stripping disks togther in LUN's then mirroring set's of the LUN's together but that is usually an expensive route (for disks, controllers and high-speed interconnects). as always the specific man pages for which ever implementation are the best sources for info. HTH -p -- ~~o0OO0o~~ Pete Wright www.nycbug.org NYC's *BSD User Group ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
