Koozali.org: home of the SME Server
Legacy Forums => General Discussion (Legacy) => Topic started by: Andrew on June 10, 2003, 05:07:12 AM
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Hi, I'm designing a new SME 5.6 server system for a client of mine, They require a tape backup, the drive I was looking at using is "Certance TapeStor Travan 40 ATAPI, Server Model" the model number is STT3401A-RY according to the information from the website this drive is compatiable with linux, but can anyone tell me if it will work with SME? Here is the website link to the drive
http://www.certance.com/products/srssDrives/STT3401A-RY.HTML
thanks in advance for your help.
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I've used one of these in a system with a 3ware7000-2 IDE RAID card and it works perfectly.
You can't use this and software RAID as the tape must be an IDE master to work, and both hard drives must be masters for RAID to work correctly.
Unlike the Highpoint RAID carrds, the 3ware is easy to use.
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> Unlike the Highpoint RAID carrds, the 3ware is easy to use
There's nothing hard about the Highpoint RAID cards. They are just not properly supported (some, if at all) by SME. Big difference.
Andrew, if you truly value your data, I generally advise against the use of Travans. I know there are lots of them out there and there have been people who have used them successfully for years. But, after seeing time after time, sites that have relied on them get into strife when they needed their backups most only to find they are not working or cannot be restored for whatever reason, I steer well clear of them. And these are sites which run them through Windows with "supported" software that does "verify after backup" operations as well. Yet, inspite of the tapes verifying OK, they will not restore. If you must use one, make sure you do regular test restores and compare the restored files, since SME's backups are not verified.
Kelvin
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This is for a customer who's data is VERY important--tax preperation business. It tape drive is not the way to go, how should i go about backing up the data, preferably it needs to be automated so the user has to do nothing at all.
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Hi Andrew,
Don't misunderstand - I did not mean that tape drives are not reliable, I just don't trust Travan based tape drives, not all tape drives.
Up until yesterday, I used 2 main types of tape drives - the OnStream DI-30 and the Sony AIT tape drives (depending on capacity). I just got word yesterday that the OnStream Data company in Netherlands filed for bankcruptcy, so I will hold off on recommending OnStreams until I know what's happening. The Sony AITs have been fine. Also, avoid using the in built backup if you are using SME 5.6. See here :-
http://forums.contribs.org/index.php?topic=17612.msg68690#msg68690
Additionally, I would also put in a hardware based RAID / Mirroring system if your data is crucial. Like you, I have one accounting firm as a client who cannot afford to either lose data or have down time especially now, their busiest time of the year. When they had a hdd failure a couple of weeks back, I was thankful that I pushed them into the self contained Mirroring subsystem because aside from the warning alarm that came on when the drive died, the system continued working without missing a beat. When I turned up with a replacement HDD, I just pulled out the tray with the faulty drive, replaced the HDD and plug it back in, all while the system continued to work and people were accessing the system, and the system automatically started rebuilding the mirror. Zero downtime. You and your client will thank your lucky stars you put it in. Otherwise, in my case, I would have more than 20 accountants, staff members and company directors sitting around while I fiddled with their server hdds. In this type of situations, don't try and save the client money by putting in software RAID. No need to remember commands to type to do RAID recovery, etc.
Kelvin
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Thanks for you comments. I will look into getting a Sony AIT tape drive, I actually ran across that post earlier on my searches, but what should i use inplace of the flexbackup-dump method should i get "Arkeia." Also what would you reccomend for a raid card that has good support for SME. I would like to implament both raid and tape backup.
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Hi Andrew,
Arkeia is a good choice for replacement backup program. You just need to get used to the java interface for restoring files. Arkeia can also take advantage of the MIC module in the AIT tapes (more details about the MIC at the Sony Web Site).
I sell an OS independent RAID-1 subsystem by Accusys. It takes up 2 half-height drive bays but is a self contained mirroring system with hotswap capability and automatic rebuild facilities. No drivers required for the unit at all as long as the IDE controller you are connecting it to (whether on board or on a separate card) is *fully* supported by SME.
If you want RAID 5 capabilities, then you will need to find a supported card (like the 3ware ones or possibly the Adaptec ones).
** fully supported **
See another thread on the forums about VIA southbridge support
Kelvin
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Are you talking about the "IDE RAID Solution ACS-7500 RAID Kit" at http://www.accusys.com.tw/prod.htm?
This looks like the perfect solution. Would you have a seperate OS drive and then the raid array for data or just put it all together? You mentioned you sell this raid system. Where can I get info to purchase it? What kind of cost am I looking at.--I am still looking into the tape backup drives and software.
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Hi Andrew,
>ACS-7500
Yep, that's the critter !
>Where can I get info to purchase it?
Depends on what your location is. I'm sure there are local resellers. The unit itself sells for AUD $ 550.00 here.
Kelvin
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Hi Kelvin,
After reading about your use of IDE RAID, I wanted to get an opinion ...
I've always read that IDE is primarily consumer grade hardware, that they can run forever under very light load situations but once they begin to see a real load - like under multiple user situations - performance goes in the toilet and they start to fail. Is this true? Obviously you're seeing good performance and reliability from IDE drives or you wouldn't trust it in the environment you describe here.
Have you had much experience with SCSI arrays? Do you have any opinions on performance and reliability with SCSI compared to IDE? My ideas about IDE and SCSI may no longer be valid, info from someone with some real world experience on comparable systems would be appreciated.
BTW: I work as a programmer for a living and am a geek as a hobby - If there's any concern, I won't be making any money off your knowledge or anything like that...
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G'Day Dave,
>I wanted to get an opinion ...
No worries. Opinions are free. Whether anyone else agrees with them or not is another matter :) !
> I've always read that IDE is primarily consumer grade hardware
That assumption continues to live on to this day. However, even mission critical workstations these days run IDE drives (yes, I still have one or two people who starts off by asking for SCSI but as past experience have shown, this does not make their drive any LESS likely to fail).
SCSI drives still technically handle multiple requests better - it's got command queueing while IDE Drives don't. How significant this is in real like is hard to say - in a single drive machine, probably noticable. In a large RAID array, harder to say because requests are divided amongst multiple drives. As for IDE drives failing under load, that's probably more a reflection of the quality of the individual drive or brand than the IDE technology. Performance is not an easy thing to judge because you can only truly "feel" any differences if you have the same thing software and load conditions running on the two different RAID technologies side by side in a real world environment. I always take simulated benchmarkings with a grain of salt (about peppermill sized grain!). Your choice of a RAID level to employ also makes a difference to the performance gain / loss. With hardware RAID-1, there is usually no performance loss / gain over a single drive setup. A quick search on google will lead to to more than you might possibly want to know about the different RAID levels. The controller in use will probably make or break your RAID array and its performance.
>Have you had much experience with SCSI arrays?
Mostly with Mylex based cards and the Compaq SmartArray controllers. And yes, in each system, they have had drives die as well. With Compaq, because of the extra warranty purchased with the servers, they ship out replacement drives overnight. However, in large networks like the ones where these servers are running, I've always included a spare unit in the costings, so they always have a spare on the shelf to replace any failed units on the spot.
I find these days that cost and availability is the real factor in choosing between the technologies. SCSI Based solutions are still very much more expensive than IDE based ones. Since I only ever deal with new products, no second hand hardware pricing considered (as you can sometimes pick up previously owned and loved (or loathed) ones quite cheaply). Also, most companies and shops don't stock as wide a range of SCSI drives (if ANY at all). So in a pinch, you cannot count on rocking up to any old shop to pick up a replacement drive. This actually counts more in the eyes of the client when you need to replace any failed drives.
>I won't be making any money off your knowledge or anything like that...
That's OK. I wouldn't mind sharing anyway. "Knowledge" ... Hmmm... These days, I wouldn't call it that... Most things people know are not absolute anyway, even when they think it is !... :)
Cheers !
Kelvin
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I have decided to use your RAID solution Kelvin--Thanks. Anothe question I have is what SCSI cards does SME support? I can only find the sony tape drives you told me about in a SCSI model, so i will need to add SCSI support to the machine. Thanks
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Hi Andrew,
I have used various Adaptec, Tekram and Initio-based PCI SCSI cards with no problems. The best place to check will be RedHat's HCL.
I usually use the IDE version of the AIT-1 (due to costs) but have not had any problems with the SCSI ones either.
Kelvin
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I'm almost done gathering all the information for this system build. I just have one more question concerning the raid. Should i use the raid system for both the system and data, or should i set the system up on a seperate drive?
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Hi Andrew,
If you believe in keeping things simple, then keep the OS and data on the same RAID system.
Under Windows Servers, there is a performance advantage in separating the two. I don't know enough about linux (as you can probably tell, my background is Windows !) to tell you with any certainty if it is the same. However, because of the use of the swap partition, it probably is the same. How much of a performance gain, I could not tell you. If you have enough RAM in your system, you will probably negate the reliance on the swap partition anyway.
Kelvin
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Thanks for you help, i will do this and hopefully won't have too many problems with the server setup.