Re: Machine Replication
At 15:20 7/21/2005, Eli K. Breen wrote: All, Does anyone have a good handle on how to replicate (read: image) a freebsd machine from one machine to an ostensibly similar machine? So far I've used countless variations and combinations of the following: dd(Slow, not usefull if the hardware isn't identical?) tar (Doesn't replicate MBR) rsync (No MBR support) Norton Ghost (Doesn't support UFS/UFS2?) G4U (little experience with this) I've found a combination of dd + tar works great, as documented. Stick the new drive in the box to be duplicated, use dd on the first (forget how many) sectors to copy the mbr and partition tables over, then use a tar pipe to copy from one drive to the other, preserving all perms and so forth. Barring that, commercial single-disk duplicators aren't THAT expensive. Hell you could just use a cheap raid card to raid-1 mirror the drive, then yank it out and toss it in another box, which I've done on occasion when pressed. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: dangerous situation with shutdown process
At 15:19 7/14/2005, Wilko Bulte wrote: On Thu, Jul 14, 2005 at 12:14:49PM -0700, Kevin Oberman wrote.. Date: Thu, 14 Jul 2005 20:38:15 +0200 From: Anatoliy Dmytriyev [EMAIL PROTECTED] Sender: [EMAIL PROTECTED] Hello, everybody! I have found unusual and dangerous situation with shutdown process: I did a copy of 200 GB data on the 870 GB partition (softupdates is enabled) by cp command. It took a lot of time when I did umount for this partition exactly after cp, but procedure finished correctly. In case, if I did âshutdown âh(r)â, also exactly after cp, the shutdown procedure waited for âsyncâ (umounting of the file system) but sync process was terminated by timeout, and fsck checked and did correction of the file system after boot. System 5.4-stable, RAM 4GB, processor P-IV 3GHz. How can I fix it on my system? The funny thing about all the replies here.. is that this guy is not saying that sync doesn't work. He's saying that the timeout built into shutdown causes it to *terminate* the sync forcibly before it's done, and then reboot. All finger pointing about IDE, SCSI, softupdates, and journals aside.. I think all he wants/needs is a way to increase that timer. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: atapci VIA 82C596B UDMA66 controller: problem for 5.X ?
At 08:47 2/16/2005, Rob wrote: --- Mars Trading [EMAIL PROTECTED] wrote: This idea may seem useless but what have you got to lose? Have you tried changing bios setting for hard drive mode to auto or something other than LBA? Maybe LARGE or CHS? Is there a risk that I lose all data on my disk, when changing this in the BIOS? I wouldn't exactly call it a risk -- if you change the disk geometry in the bios, you will lose all the data on that drive, guaranteed. Of course, if you don't write anything to it, you can just change it back and it'll still be there. If you don't write anything to it though, it's not going to boot. BTW: During the fresh FreeBSD install, I have never encountered a choice for formatting with or without LBA. In the Fdisk window, I choose 'use entire disk for FreeBSD', and in the partition window I have set 'newfs' for all partitions. LBA is a BIOS thing as was mentioned, not a freebsd install thing. It's an abstraction layer between the drive and the controller. ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: drive failure during rebuild causes page fault
At 18:16 12/15/2004, Gianluca wrote: barracudas and at this point I wonder if it's best to go w/ a small hw raid controller like the 3ware 7506-4LP or use sw raid. I don't really care about speed (I know RAID5 is not the best for that) nor hot swapping, my main concern is data integrity. I tried to look online but I couldn't find anything w/ practical suggestions except for tutorials on how to configure vinum. If you don't care about hot-swapping, then you don't really care about (or need) RAID-5. It doesn't offer any additional data integrity, but no RAID level does. What RAID does for you is allow you to survive an outright drive failure without losing any data. No RAID level can save you from buggy software writing garbage to the disk, transient disk errors, or the myriad other events that are far more common than a single drive just dying on you. Using RAID-5 as an example, during normal operations, a chunk is written to the disk and the controller (or software) calculates the bitwise XOR of all the blocks involved and writes that value into the parity stripe. During read operations, this parity data is not read or verified -- doing so would be pointless because there is no way to tell if it's the parity-stripe or the data-stripe that's lying if the two don't jive. So, during normal operations (all drives up and functioning) RAID-5 functions readwise as a RAID-0 with one less disk than you really have, and as a somewhat slower array during writes. If a drive completely fails, then the parity stripe is always read up, and the missing data stripe is reconstructed from the parity data -- unless the parity stripe happens to fall on the missing drive for the stripe set you're currently accessing, in which case it is ignored and for that single access the array functions just as it would if a drive hadnot failed. If you're thinking of using RAID instead of good timely backups, you need to go back to the drawing board, because that is not what RAID is intended to replace -- and is something it cannot replace. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: drive failure during rebuild causes page fault
At 18:57 12/15/2004, Gianluca wrote: actually all the data I plan to keep on that server is gonna be backed up, either to cdr/dvdr or in the original audio cds that I still have. what I meant by integrity is trying to avoid having to go back to the backups to restore 120G (or more in this case) that were on a dead drive. I've done that before, and even if it's no mission-critical data, it remains a huge PITA :) That's true. Restoring is always a pain in the ass, no matter the media you use. thanks for the detailed explanation of how RAID5 works, somehow I didn't really catch the distinction between the normal and degraded operations on the array. what would be your recommendations for this particular (and very limited) application? Honestly I'd probably go for a RAID1+0 setup. It wastes half the space in total for mirroring, but it has none of the performance penalties of RAID-5, and upto half the drives in the array can fail without anything but speed being degraded. You can sort of think of this as having a second dedicated array for 'backups' if you want, with the normal caveats -- namely that destroyed data cannot be recovered, such as things purposely deleted. RAID5 sacrifices write speed and redundancy for the sake of space. Since you're using IDE and the drives are pretty cheap, I don't see the need for such a sacrifice. Just make sure the controller can do real 1+0. Several vendoers are confused about what the differences are between 1+0, 0+1, and 10 -- they mistakenly call their raid 0+1 support RAID-10. The difference is pretty important though. If you have say 8 drives, in RAID 1+0 (aka 10) you would first create 4 RAID-1 mirrors with 2 disks each, and then use these 4 virtual disks in a RAID-0 stripe setup. This would be optimal, as any 4 drives could fail provided they all came from different RAID-1 pairs. In 0+1, you first create two 4-disk RAID-0 arrays and then use one as a mirror of the other to create one large RAID-1 disk. In this setup, which has *no* benefits over 1+0, if any drive fails the entire 4-disk RAID-0 stripe set that the disk is in goes offline and you are left with no redundancy -- the entire array is degraded running off the remaining 4-disk RAID-0 array, and if any of the drives in that array fail, you're smoked. If you want redundancy to avoid having to possibly restore data, and you can afford more disks, go 1+0. If you can't afford more disks, then one of the striped+parity solutions (-3, -4, -5) are all you can do.. but be ready to see write performance anywhere from ok on a $1500 controller, to annoying on a sub $500 controller, to downright retardedly slow on anything down in the cheap end -- including most IDE controllers -- Look up the controller, find out what I/O chip it's using (most are intel based, either StrongARM or i960) and see if the chip supports hardware XOR. If it doesn't, you'll really wish it did. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to [EMAIL PROTECTED]
