Tape Drives vs Blu Ray

[scracha]

Just spent an hour or so getting a stuck tape out of a Sony AIX tape drive (hey, I've never done it before). Hopefully it's not farked.

Anyways......excuse my ignorance but why are companies still deploying magnetic tape? Are conventional hard drives or blu-ray disks the way to go or do tape drives still have a useful role?

Pro's/cons please...............

[PirateJafa]

Tape drives.

Cassette lives in my car's radio.

It's a lot easier to get a stuck cassette out than a stuck disc.

On a more serious note though, even a Blu-ray disc doesn't hold a fraction of what is needed for a full backup.

[xwhatsit]

Best medium to back up onto is punched card. Then you can hire 1000 Chinese kids to decode it by hand if your reader blows up too.

[RantyDave]

why are companies still deploying magnetic tape?
There's something to be said for a backup that can be restored if the site which it was backing up was totally nuked in, for instance, an earthquake. I also think the "air gap" security of a tape kinda appeals in a world where actual faults are one thing, "getting hacked" is another and operator SNAFU's are more common than the previous two added together.

No doubt some SAN nazi's will quite happily sell you a versioned filesystem with an offsite backup using IP over SCSI and zzzzzzZZZzZzzZZzzzzzzzz. Sorry, narcolepsy don't you know.

Anyway, why would I give a shit. I just got one of these (http://www.apple.com/nz/timecapsule/) and if it won't fit on there it's someone else's problem. Yours, by the sounds of things.

Dave

[pete376403]

If you're referring to computer backup - DVDs (even Blu ray) don't have enough capacity for medium to large systems. Current LTO Ultrium tape drives are 400/800Gb (native/compressed) or better. In a 90x90x20mm package. The only thing that comes close is a hard drive in a removable caddy, but are you going to trust a courier to handle that (ie offsite storage) in a manner that will allow it to be re-used?

[pete376403]

No doubt some SAN nazi's will quite happily sell you a versioned filesystem with an offsite backup using IP over SCSI .Dave
Too slow (unless you want to pay Telecom megabucks for a decent fast link)
Backing up 50 odd gig from our Auckland site takes about 21 hours (because we don't have a fast link, but becuase its telecom it's still damned expensive)

[riffer]

Slow? Don't talk to me about slow.

Due to the tight-arsed-ness of the director of our company when it comes to IT infrastructure I'm still trying to do differential backups of our main File server, Document server, CMS Server and Mail server, while also doing a Full backup of the 2nd work server. All of that onto one LTO jukebox (12 tapes/10TB compressed).

I'd love to have the option of a SAN halfway inbetween and syncing on the hour to that with diffs to LTO each night but its about 30 large for a decent 10TB SAN.

Maybe next year. :blink:

[pete376403]

Slow? Don't talk to me about slow.

Due to the tight-arsed-ness of the director of our company when it comes to IT infrastructure I'm still trying to do differential backups of our main File server, Document server, CMS Server and Mail server, while also doing a Full backup of the 2nd work server. All of that onto one LTO jukebox (12 tapes/10TB compressed).

I'd love to have the option of a SAN halfway inbetween and syncing on the hour to that with diffs to LTO each night but its about 30 large for a decent 10TB SAN.

Maybe next year. :blink:
Not that much - how about an Intel "McKay Creek" -we've got one, iSCSI attached, running Open-E, and it's got 5 x 300g SAS drives and space for 7 more. IIRC it was about 10 -12K about 6 months ago. Or do you want fibre channel, etc?

[riffer]

Not that much - how about an Intel "McKay Creek" -we've got one, iSCSI attached, running Open-E, and it's got 5 x 300g SAS drives and space for 7 more. IIRC it was about 10 -12K about 6 months ago. Or do you want fibre channel, etc?

5 x 300GB = enough to back up the email maybe Pete. :(

[avgas]

we have a newish HP tape backup at work and it is absolute rubbish. Blue ray is good - but the tech hasnt reached good pricepoint yet.
I had a good solid state backup on my last laptop - and at $200 it was cheap enough to fit in a server. However the true solid state drives are $$$$
I still believe the future is solid state - from everything like hard drives to engines.
But then we will all get fat i suppose - just like on Wall-E

[-JT-]

It's already been said but ... we're backing up 700GB a night to a 400/800GB tape ... it takes around 5 hours. Blu-Ray could be an option for home but not for most businesses.

[riffer]

If you need to back up 5-7 TB a night you're stuffed unless you go the LTO jukebox unfortunately.

[pete376403]

5 x 300GB = enough to back up the email maybe Pete. :(

Yeah ok but I did say "and space for 7 more drives" and they dont have to be 300s - terabyte SATAs are pretty cheap now (although quite a bit slower than SAS)

[riffer]

Yeah, you're probably right.

About $10K for a 20 pack of Caviar SE Green Powers is the cheapest I can find (have to allow for some units in the RAID dying - we're hard on drives).

Plus the $10-12K for the SAN you're suggesting.

means you pay over $20K for the hardware.

And how much for a rock-solid SLA? Probably about $10K for a three-year contract.

$30K. I rest my case.

[rottiguy]

I believe if you have lots to move you can use a burst transmitter via satellite but it used to cost around $500/month for the gear. Not sure what the cost and options are these days

[pete376403]

Yeah, you're probably right.

About $10K for a 20 pack of Caviar SE Green Powers is the cheapest I can find (have to allow for some units in the RAID dying - we're hard on drives).

Plus the $10-12K for the SAN you're suggesting.

means you pay over $20K for the hardware.

And how much for a rock-solid SLA? Probably about $10K for a three-year contract.

$30K. I rest my case.
The Intel box without any drives retails for $5K5.
The SLA, well I don't know, it has a three year warranty and if anything fails, I change the parts myself (as in the case of one drive that carked) Hot plug etc. quite a nice unit. Our one is probably way over specced, dual quad-core Xeons, 8 gig ram, could have been cheaper.

[Gremlin]

The only thing that comes close is a hard drive in a removable caddy, but are you going to trust a courier to handle that (ie offsite storage) in a manner that will allow it to be re-used?
I wouldn't trust a courier with anything really... handle backups myself normally (for those that pay for it :lol:)

the issue with a hdd in a caddy is the speed... quite limiting compared to a normal sata/whatever interface, when you are dealing with 100's of gb.

riffer: as a general rule, best not to buy all your hdd in one pack, because if there is an issue with a batch... well... suffice to say I have heard (but thankfully not had the personal pleasure) of raids being lost when multiple drives failed at once. Space the buying out, to hopefully buy from different batches.

[scracha]

I wouldn't trust a courier with anything really... handle backups myself normally (for those that pay for it :lol:)

the issue with a hdd in a caddy is the speed... quite limiting compared to a normal sata/whatever interface, when you are dealing with 100's of gb.


Does anyone actually know anybody who's lost two drives in a RAID array at once or is this another of these IT urban myths?

Backing up the ReadyNAS, yep...USB takes ages and I've only got 3x320gb drives shoved in the thing. eSATA on a Synology aint too bad though....seemed about 3x quicker.

So in response to my original question. Tape is still useful for offsite backups using a courier that are over 50GB in size? How long does tape last and what are the limits on the number of times it can be read/written to. Is it standard practice to verify data on a tape drive after writing. Dunno much about tape at all so again, apologies.

[Gremlin]

Does anyone actually know anybody who's lost two drives in a RAID array at once or is this another of these IT urban myths?
I believe I do... a mate and I were talking about single drive failure a while ago, but iirc, he brought up multiple drives failing...

Its also dependent on what drives you spec, what kind of abuse you give them, and how they subsequently cope. Some applications are terrible on drives, and if the drive is vulnerable... it doesn't help.

[Ixion]

I've experienced a dead server when three disks failed in a RAID 5 array (two totally dead one flakey as).

But, I must say , it was at a client site , and a cooling fan had gone. I don't know how long elapsed between the first disk going out and the total collapse (not long, but could have been several days). We just got called when "The computer's stopped working "

[Sanx]

the issue with a hdd in a caddy is the speed... quite limiting compared to a normal sata/whatever interface, when you are dealing with 100's of gb.

Erm, this might be the case if you're dealing with an external USB / Firewire attached drive, but HDDs in caddies are the absolute norm for any decent-sized server; all hot-plug drives live in caddies of some description.

And as eSata enclosures are available for peanuts these days (I bought one for $45 the other week, and it had USB2 and Firewire on it as well), there's not even an excuse for not using one, unless you don't happen to have any spare SATA ports on a motherboard.

[pete376403]

The Intel box I referred to supports hot spare(s) among other things. Gives you one more chance to organise replacement disk, ie even after one disk died the hot spare took over, so it was still R5, business as usual. If another disk had failed in that time then it would have been in degraded model but still working. If a third disk had died then it would have stopped

[scracha]

Yeah, even the cheap(ish) NAS' units have hot swappable drives.

[Gremlin]

Erm, this might be the case if you're dealing with an external USB / Firewire attached drive, but HDDs in caddies are the absolute norm for any decent-sized server; all hot-plug drives live in caddies of some description
woops... true I guess... was sorta meaning the usb ones, not hot swappable/esata etc

technically... the ones for hot swappable are called drive bays or whatnot :bleh:

[RantyDave]

Does anyone actually know anybody who's lost two drives in a RAID array at once or is this another of these IT urban myths?
I believe it. The drives were made by the same manufacturer, to the same design, were part of the same batch, were treated the same in transit, were powered up at the same time and had identical workloads until one of them failed. It's not surprising the second is not far behind.

I worked on a big (for the time) ISP rig once and we had two big (for the time) LDAP servers shared on a load balancer. One day the LDAP went down and there was much waving of arms and shouting about load balancers being a piece of shit. Upon picking through the wreckage it became apparent that one of the servers had lost the plot a number of days prior, the balancer had failed over to the other one and the thing that had failed was the script that told the admin when it was time to go press the white button. I think a similar thing happens with RAID's pretty frequently.

Dave

[Gremlin]

I think a similar thing happens with RAID's pretty frequently.
Depends on the raid, the features of the controller, what kind of capabilities re notifying there is (if its been set up :eek:) etc. There is also the old fashioned, check on it, see if its popping anything up (if it can't email or something).

From experience, you generally have some weird issues pop up just before the drive finally dies (sometimes it may even struggle on for a couple of days), but the issues depend on how good the machine is with surviving drives dropping out. Some will crash, and you restart and they are fine... some, the users don't even notice a performance hit.

You sure as hell move fast when that drive dies tho... tis a lot easier sticking another in, and the raid manager going... ooh, is that my new drive, cheers, let me rebuild for you... as opposed to... sitting there rebuilding the raid from backups... :niceone:

[Matt]

LTO 4 is 800GB native / 1.6TB compressed - or disk to disk backup is a good option - even "named" brands (e.g. IBM) would sell you a iSCSI/SAS/SAN array for ~$5k, with $700 ish for each 1TB SATA HDD.

RAID 6 (DP) would protect against 2 disk failure, but at the expense of useable capacity - worth looking at as recovery time is massive on 1TB drives!