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RE: [CentOS] Tape drive recommendations
by Mark Schoonover 29 Mar '07

29 Mar '07

Les Mikesell wrote: > Mark Schoonover wrote: >> Les Mikesell wrote: >>> Mark Schoonover wrote: >>>> John R Pierce wrote: >>>>> Aron.Darling(a)Emulex.Com wrote: >>>>>> Loader are totally a love/hate relationship. They do make life a >>>>>> lot easier as they do the tape movements for you which can be a >>>>>> tedious thing at times. With a loader or library you can script >>>>>> the entire operation with tar, MTX and MT and let cron do all the >>>>>> work for you. Always look for the OEM rather than buying the name >>>>>> brand equipment, they are most always the same HW and FW with a >>>>>> different model number in it. >>>>> otoh, its hard to beat a 3 year warranty and on location support >>>>> from the same vendor as your server hardware, assuming your a >>>>> brand name shop in the first place.... hugely reduces finger >>>>> pointing when there's a complex issue to resolve. with OEM >>>>> hardware bought on the whitebox market, you're often faced with >>>>> replace or self-repair option at cost. >>>>> >>>> Having used a 20 tape library, and suffering through restores with >>>> AIT2 tapes taking 10-12 hours per tape, I gave up on them. I went >>>> with good old rsync, and built up a 4 TB system to handle backups. >>>> Once configured, it's nearly a 100% hands off solution. You can >>>> read about what I've done here: >>>> http://marks-tech-pages.blogspot.com Works great especially for >>>> TBs of data that needs to be backed up every day. >>> If you want something that stores the backups much more efficiently >>> (with a price in processing to do it), look at backuppc: >>> http://backuppc.sourceforge.net/ >>> >>> It compresses everything and hardlinks all duplicates so you can >>> keep about 10x what you'd expect online, and it has a nice web >>> interface for browsing the backups and doing restores. >> >> Thanks Lee. I did look at backuppc before, and I didn't want >> anything that compresses files, or used a web interface. Using >> rsync, it's a matter of scp to restore, and that's it. I do use >> hardlinks to duplicate data, so my storage requirements are kept as >> small as possible. Just about any CentOS system can be configured to >> run backups in the manner I've written up, nothing extra to install >> or learn. So, like most things, it boils down to individual needs >> and expertise. I know for myself, tape backups just weren't working >> well at all. >> > > Backuppc can be configured to not compress, although I think the > filenames are still somewhat mangled and don't have their real > attributes so you can't access them directly. The web interface is > also optional and there are command line tools for everything you > need. It is handy to be able to download a single file or tar/zip > archive directly through a browser, though - and in the latest > version you can edit the configuration through the web interface. I've thought about adding a web restore so users can restore their own files to their own home directories. Most of my problems come from my graphics dept, where it's not uncommon for them to 'accidently' delete 500GB of data. It would be nice to offload those kinds of requests to the users, but only to a point, and on an employee by employee basis. Mark

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RE: [CentOS] Tape drive recommendations
by Mark Schoonover 29 Mar '07

29 Mar '07

John R Pierce wrote: > Mark Schoonover wrote: >> Cost is another factor. An Exabyte LTO3 1x7 loader is MSRP $6500, >> with 20 tapes $1130 in a pack. My 4TB backup server cost just under >> $5000 at the time, cheaper today. Then, you have the daily admin of >> flipping tapes. Disks run without intervention once configured, and >> it's nice to have especially if you have employees working over the >> weekends, or on holidays. >> > > > HP's version of that same LTO3 1/8 autoloader is around $5000 street > price (sometimes under $4500). The Quantum OEM version > ("Superloader") is about the same. > > of course, 20 LTO3 tapes is 16 terabytes. and you can have another > 16 terabytes in archive for another $1100 or whatever. That 1/8 > autoloader holds 8 of them, which is 6.4 terabytes online with no > operator intervention required until it comes time to ship a box of > tapes to the offsite vault. > Assuming 2:1 compression will you get 16TB, but with my data, 1.3:1 is more realistic. Now that you mention it, a similar disk backup system is located 100 miles away in a colo site. Every night I do offsite backups, automatically. No shipping tapes, or other user intervention. Tape backups require user intervention everyday. There's no way around it, especially if you're testing your backups for reliability. Mark

2 1

Complex sendmail alias handling
by Steve Campbell 29 Mar '07

29 Mar '07

Getting in late on this one, but if I didn't need to spend money, couldn't spend money, or what ever the reason may be, and the aliasing was something that needed changing on a schedule, then why not just set up multiple alias files, run cron to replace them when needed, and "newaliases", all in cron scripts? You would need to maintain as many versions as required, but sounds like it might work with minimal effort and expense. Complex is a relative term, and this may be oversimplifying, but it would work. Steve Campbell campbell(a)cnpapers.com Charleston Newspapers

5 18

NPTL degraded?
by Lonny Selinger 29 Mar '07

29 Mar '07

I'm not sure what has happened but for some reason my CentOS 4 system is showing me using default threads?? # getconf GNU_LIBPTHREAD_VERSION linuxthreads-0.10 # uname -rimpv 2.6.9-42.0.10.EL #1 Tue Feb 27 09:24:42 EST 2007 i686 athlon i386 I could have sworn it used to show: NPTL 2.3.4 Like a couple other machines. Any ideas what might have changed this or how I get it back??? the devel package for NPTL is installed but from my understanding that has little to do with why getconf is showing this. I'm feeling new here :-) TIA -- Lonny -- "To mess up a Linux box, you need to work at it; to mess up your Windows box, you just need to work ON it."

3 7

pagecache corruption on Tyan S3870
by Dan Halbert 29 Mar '07

29 Mar '07

A couple of months ago I reported some problems with a batch of Tyan K8SSA (S3870) based machines. We are continuing to have an odd problem with these boxes, and if anyone has seen something similar elsewhere, I'd appreciate hearing about it. These boxes are running Centos 4.4 x86_64 with kernel 2.6.9-42.0.3.ELsmp. They are dual Opteron 265's (dual core) with 4x2GB DIMM's. The DIMMs used to be mixed sizes, but Tyan recommended making them all the same, and the vendor made the substitutions. We have also clocked the memory down from 400 MHz to 266 MHz, also on the advice of Tyan. The symptom is that some large (700MB to >1GB) files opened for read and then closed show corruption in the pagecache. One or more 4k blocks in a file will be completely trashed. It's as if a random page of other data is substituted. A reboot or a flush of the pagecache fixes the problem, so it's only in the pagecache, not on disk. We are doing regular MD5 checksums of the files, which shows up the problem, in addition to having our application crash from time to time. We have some older Tyan motherboards that don't show this problem. At this point it seems it is either a hardware problem or a kernel motherboard-support problem, but it's pretty baffling. Thanks, Dan

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RE: [CentOS] Tape drive recommendations
by Mark Schoonover 29 Mar '07

29 Mar '07

John R Pierce wrote: > Aron.Darling(a)Emulex.Com wrote: >> Loader are totally a love/hate relationship. They do make life a lot >> easier as they do the tape movements for you which can be a tedious >> thing at times. With a loader or library you can script the entire >> operation with tar, MTX and MT and let cron do all the work for you. >> Always look for the OEM rather than buying the name brand equipment, >> they are most always the same HW and FW with a different model >> number in it. > > > otoh, its hard to beat a 3 year warranty and on location support from > the same vendor as your server hardware, assuming your a brand name > shop in the first place.... hugely reduces finger pointing when > there's a complex issue to resolve. with OEM hardware bought on the > whitebox market, you're often faced with replace or self-repair > option at cost. > Having used a 20 tape library, and suffering through restores with AIT2 tapes taking 10-12 hours per tape, I gave up on them. I went with good old rsync, and built up a 4 TB system to handle backups. Once configured, it's nearly a 100% hands off solution. You can read about what I've done here: http://marks-tech-pages.blogspot.com Works great especially for TBs of data that needs to be backed up every day. HTH Mark Schoonover IS Manager American Geotechnical - California, Nevada and Arizona V-> 858.450.4040 F-> 714.685.3909 C-> 858.472.3816 "Eternity is a very long time, especially towards the end." -- Stephen Hawking

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RE: [CentOS] Tape drive recommendations
by Mark Schoonover 29 Mar '07

29 Mar '07

Joshua Baker-LePain wrote: > On Wed, 28 Mar 2007 at 10:07pm, Mark Schoonover wrote > >> Having used a 20 tape library, and suffering through restores with >> AIT2 tapes taking 10-12 hours per tape, I gave up on them. I went >> with good old > > One of the lovely bits about LTO3 -- 400GB native, 80MB/s => restore a > whole tape in under 2 hours. Joshua, 200 gigs an hour is pretty good for a tape, but what happens if the tape you've backed up to is bad, or has a bad spot? You've lost your backup. 400GB in drives is a fraction of the cost of tapes these days. I do agree, my max throughput over a quiet gigbit network is going to be around half the speed of the LTO, I look at the fact that I'm only backing up the daily changes, not an entire server like you'd do to tape. With rsync doing compression over SSH, it looks like I'm backing up an entire 1.3TB system in 90 mins. Sure, you can do differental backups to try to keep your number of tapes to a minimum. Backing up straight to disk ends up being faster all around, plus it's on a RAID5 system so loosing a drive isn't all that big a deal. Going to disk is also fast enough, I can run hourly backups during business hours. Where LTO tapes will outrun is during a total server failure where I have to restore all data back to a server. Then my network becomes the bottleneck, but you still won't have to gamble spanning across multiple tapes to fit >400GB of data. My past problems have never been with backing up, it's been with restoring the data. Either too slow to restore, or since I needed 10 tapes to backup, I'd end up with one of them having a bad spot that would abort the restore. The only way to know for sure if your tapes are 100% is to try to do an entire restoration. Simply running a tape verify isn't enough. Cost is another factor. An Exabyte LTO3 1x7 loader is MSRP $6500, with 20 tapes $1130 in a pack. My 4TB backup server cost just under $5000 at the time, cheaper today. Then, you have the daily admin of flipping tapes. Disks run without intervention once configured, and it's nice to have especially if you have employees working over the weekends, or on holidays. These were just my requirements, and my thought processes that lead me away from tapes all together. YMMV, your specifics are probably different. Mark

2 1

RE: [CentOS] Tape drive recommendations
by Mark Schoonover 29 Mar '07

29 Mar '07

Les Mikesell wrote: > Mark Schoonover wrote: >> John R Pierce wrote: >>> Aron.Darling(a)Emulex.Com wrote: >>>> Loader are totally a love/hate relationship. They do make life a >>>> lot easier as they do the tape movements for you which can be a >>>> tedious thing at times. With a loader or library you can script >>>> the entire operation with tar, MTX and MT and let cron do all the >>>> work for you. Always look for the OEM rather than buying the name >>>> brand equipment, they are most always the same HW and FW with a >>>> different model number in it. >>> >>> otoh, its hard to beat a 3 year warranty and on location support >>> from the same vendor as your server hardware, assuming your a brand >>> name shop in the first place.... hugely reduces finger pointing >>> when there's a complex issue to resolve. with OEM hardware bought >>> on the whitebox market, you're often faced with replace or >>> self-repair option at cost. >>> >> >> Having used a 20 tape library, and suffering through restores with >> AIT2 tapes taking 10-12 hours per tape, I gave up on them. I went >> with good old rsync, and built up a 4 TB system to handle backups. >> Once configured, it's nearly a 100% hands off solution. You can read >> about what I've done here: http://marks-tech-pages.blogspot.com >> Works great especially for TBs of data that needs to be backed up >> every day. > > If you want something that stores the backups much more efficiently > (with a price in processing to do it), look at backuppc: > http://backuppc.sourceforge.net/ > > It compresses everything and hardlinks all duplicates so you can keep > about 10x what you'd expect online, and it has a nice web interface > for browsing the backups and doing restores. Thanks Lee. I did look at backuppc before, and I didn't want anything that compresses files, or used a web interface. Using rsync, it's a matter of scp to restore, and that's it. I do use hardlinks to duplicate data, so my storage requirements are kept as small as possible. Just about any CentOS system can be configured to run backups in the manner I've written up, nothing extra to install or learn. So, like most things, it boils down to individual needs and expertise. I know for myself, tape backups just weren't working well at all. Thanks! Mark

2 1

cad - 3d in linux
by devel 28 Mar '07

28 Mar '07

Hello, Anyone know program capable of import 3ds files of Autodesk, similar to 3ds studio for linux? -- -- Publicidad http://www.pas-world.com

3 2

Re: [CentOS] removed centos from dual boot laptop (now having trouble booting)
by Pitshou Asingalembi 28 Mar '07

28 Mar '07

i think that you can also use software that permit you to put xp's partition to be bootable: 1.DOS fdisk 2. Debian(only put xp's partition to be bootable and you can stop your installation). --------------------------------- Découvrez une nouvelle façon d'obtenir des réponses à toutes vos questions ! Profitez des connaissances, des opinions et des expériences des internautes sur Yahoo! Questions/Réponses.

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