Data recovery on server failure

Hi all,
According to Rule-of-thumb: each 1 GB JVM can store 350 MB of actual object data, assume we need to have 8GB data on Coherence, according to above rule:
8192/350 = ~24 JMVs required => 24*1.2 = ~29 GB
Then at least we need 2 servers of 16G RAM.
we plan to have 4 JVMs as cache servers on each of the two 16GB servers as it recommends not to have more than 4GB heap for each cluster node.
I wonder if one of the servers crashes, the 4 cluster nodes residing on it go down. If primary and backup of some data are both distributed inside those 4 cluster nodes that go down, then data is lost even the other server has enough capacity to have full redundancy.
Is this correct? If yes, how to solve it? Is Coherence smart enough to put primary and backup in different boxes, not just different node whenever possible?

922963 wrote:
Hi JK,
Thanks for response. Yes, I am worried that it may not be enough. How about if I increase memory to 32GB, ie. I have two servers, both with 32GB? Will it be sufficient in case of one physical server fail for 8GB data?
What is the point in having the 3rd physical box if two boxes have enough memory/capacity? You know, we need to pay licence according to no of CPU.
thanks,
HenryHi Henry,
actually the recommended minimum number of physical boxes is 4 so that the witness protocol participants can all be on separate machines.
But a minimum of 3 is highly recommended for a number of reasons related to partitioning:
1. If you have only 2, then you are much more vulnerable to split brain scenarios (should for some reason the two servers not be able to communicate with each other, it is harder to decide which half should be the winner). In short how do you decide which box is unable to communicate with the rest of the cluster if there are only 2 boxes?
2. You can't ensure a balanced and also machine safe partition distribution if you have a mismatching number of nodes on only 2 boxes. It would either be balanced or machine safe, but you can't get both at the same time. And you will either have mismatching number of nodes at startup or have mismatching number of nodes after one node failure.
Best regards,
Robert

Similar Messages

Data Recovery After Hard Drive Failure!

Ok, basically, I've got a 2 1/2 year old iBook G4 with a bombed hard drive, and unfortunately, the last time I backed up was around 3 months ago. Here's what happened right before the crash: some applications like Widgets and Safari were acting fluky, and it wouldn't let me open Word documents, so I restarted, because I thought it might have something to do with the fact that i had downloaded the new version of itunes not that long ago and hadn't restarted since. well, when i restarted, the gray screen with the wheel and the apple symbol went on for a really long time, and then the blue screen came up with the cursor, but nothing else happened, and the blue screen just stayed there. as far as i know, the hard drive wasn't making any unusual noises, just the usual occasional soft sounds that my hard drive has always made (there are usual sounds, right?) a piece of information that might be useful is that the hard drive was almost full (it only had about 5 GB left, which i understand is how much you should leave) could this have caused the failure maybe? anyway, i tried using the hard drive as a target and tried getting another computer to recognize it and pull the files off, but that didn't work. so, i brought it into the apple store, and they got it to boot up but using some external hard drive, i think. they tried disk utility, but that didn't see my hard drive. then the tried disk warrior, and that saw it and repaired it or something, but then it couldn't get the drive to mount. so, i'm assuming that because disk warrior didn't work and couldn't get it to mount, then other software like data rescue, etc... won't either. like all computer users, i've got some REALLY REALLY important data on there, and all the data recovery places i've gotten quotes from are pretty pricey. if the drive doesn't require physical data recovery, only non-physical, as i hope, the cheapest is still $350. even so, the person on the phone there didn't seem to know nearly as much as the people at the more pricier places. so, are there any other options besides expensive data recovery? i read something about using dd - a unix thing, but i don't know the first thing about it (http://www.macosxhints.com/article.php?story=20050302225659382) so i'm not sure i want to risk messing it up even more. and, if worse comes to worst, then i'll use a data recovery place... but can anyone tell me if they've used any of the data recovery companies below, and which ones are good?
(first three do evaluation for free, and then you decide if you want to continue based on more accurate price idea)
MacintoshDataRecovery.com
$500 non physical
$1100-1600 physical
Heroic Efforts
http://www.heroicdata.com/data_recovery
$350 non physical
ships to another (very expensive) place if physical
ACS Data Recovery
http://www.acsdata.com/index.htm
$600-700 non physical
DriveSavers.com
(recommended by Apple, probably the best, but the most steep, too)
could cost anywhere from $500-$2700 and $200 evaluation fee even if data is unrecoverable
Since this is our fourth hard drive failure in four different iBooks in 2 1/2 years, i am starting to become seriously disillusioned about the quality of the hardware Apple uses...not that i would ever get a dell or anything, but still....
THANK YOU in advance for any tips you might be able to offer, and also for reading this extremely long post!
katie
iBook G4 Mac OS X (10.4.3)
iBook G4 Mac OS X (10.4.3)

I have read good reports concerning Data Rescue although I have not used it myself.
Once you get your data back, focus on a regular (even daily) backup routine, because as you know only so well, the question is not if a drive will fail, it's when.
My condolences, by the way.

General question about data recovery from raid on windows server !

hi,
I like to buy data recovery software for windows server to recover data with any raid( or whitout raid
so the company tells me you should be sure the Raid can be recognized correctly as local disk drive first, otherwise, our product wil not help you. so if I want to recover data of my customers which has windows server with any raid form ,how
I can make this server harddisks(which is raid 1,5,6 ect)recognized coorectly as local disk drive.
thanks
johan
h.david

I have myself NAS which is connected to my computer through router.
I am started smal bussines ,and I want to use also data recovery service for deleted documents,photo's,formatted drives ect.for my customers .things that accidantally errased from raid or non raid
so I found some data recovery softwares
1-stellarphoenix data recover,which has remote acces and netwerk acces.
2--ease use data recovery software. I liked this second software,but they telling me like this,
you should be sure the Raid can be recognized correctly as local disk drive first, otherwise, our product wil not help you.
I understand the both situations you telling me.thanks
but my question is can I not run data recovery software from bootable usb stick on the smal servers like essential with raid to recover data in case of any problems that caused data loose.
I know if I install data recovery software on the server to scan it ,it wil rewrite some places on harddisk and that is not wise.
h.david

Hard Drive Failure on HP DV 6000 Pavilion laptop Windows-XPsp3 OS - Need Data Recovery Help

Hard Drive Failure on HP DV 6000 Pavilion laptop - Need Data Recovery Help
HP Pavilion DV 6108 NR, RG365UA, purchased in late 2006 at Best Buy, with Windows XP, upgraded to Service Pack 3. It has a Fujitsu hard disk, 60 gigabyte, partitioned into C: and a Recovery D:.
Windows tries to boot up, but goes to blue screen with the message: "Unmountable Boot Volume" for one second, then just keeps recycling until I force a shutdown.
BIOS Phoenix, hard drive test result: " #1-08 Fail "
I ran a disk analysis/recovery program on the Cdrive and it seemed to show the directory structure intact, and it was able to recover some files. I was using the free one from Seagate (which only recovers small files). The second pass didn't run so well, and during the third run the program said I should not proceed further, and I should contact a professional disk recovery company.
However, the D drive seems to be intact, so, I wonder if the disk is corrupted or just some aspect of the logical C drive is bad.
How can I get the D: to run the recovery software on it? The recovery disks, made by Best Buy, only proceed to the R / F / Q option screen, and when I press R, I get a blue screen every time.
Tapping the F10 key during startup gets me nowhere. Ditto the F11 key.
I dont care about the hard disk; it is the data (files, docs, images, etc) that I want.
I contacted HP to order recovery disks but they are no longer available for my computer.
Any suggestions would be greatly appreciated!
Jon
This question was solved.
View Solution.

Update...
I found a website that offers the following:
http://www.computersurgeons.com/p-13442-recovery-kit-435422-001-for-hp-model-number-dv6108nr.aspx
Recovery Kit 435422-001 For HP Model Number dv6108nr
Price: $27.00
Recovery Kit Set (An Entire Image of the Computer hard drive when the computer was new)
But I wonder how useful it would be. Early XP , no doubt. And if my hard disk problem is a mechanical fault, would any recovery disk even work? The disks made by Best Buy when I bought mine new in 2006 don't do anything more than go to the R /F/ Q screen and then goes to a blue screen when I press R (to recover the OS and apps and data files). And, as I wrote, it is the data that I want, not the disk drive.

MacBook Pro hard drive failure- data recovery possible?

Hi everyone, I have a June 2009 MBP that stopped turning on the other day and it just sits on a gray screen when trying to boot up. I had it taken in to a small little authorized Apple repair shop since I am living out in BFE and they said it has a hard drive failure which is causing the problems. They said there is no way to recover the data. Is that right? I'd imagine there has to be someway to recover it. Is there somewhere I can send it in or something? At this point even if it were to cost a lot I'd like to get the data off of it if there is the possibility.
Inb4: should've backed it up!

You may be able to boot from an external hard drive and repair the disk enough to copy the data from it, even if it will no longer boot. There are a number of hard drive recovery services. Apple even lists a couple of them (http://support.apple.com/kb/HT3974) that are authorized to recover data from hard drives without voiding the warranty. The warranty is not an issue with a machine from 2009, but those are high quality, reputable companies.
Most such companies have you send them the hard drive and they will give you an estimate of how much it will cost to recover the data, if possible. Some people have reported that Data Rescue 3 comes with a coupon for free diagnostics and $100 off data recovery from The Data Rescue Center. That was a couple of years ago. I don't know if the same deals are in place now.

Hard drive failure - options for data recovery and AppleCare coverage

I have been handed a relative's 12 month old MacBook Pro with a factory-installed 500GB hard drive which appears to have failed. When attempting to boot the MacBook I am met with the classic clicking and grating noise which I know is a tell-tale sign of hard drive failure. The drive will not boot and I am shown the question mark folder icon, indicating that the operating system cannot be found. Have booted into internet recovery mode, Disk Utility appears to have found no sign of the hard drive's existence and shows none of its partitions. I have attempted putting the MacBook into FW target-mode and mounting the disk from another laptop, but to no avail; while it will go into target mode the drive simply isn't visible. The SATA connection to the drive is definitely OK - I have tested with another 2.5 inch hard drive which showed up fine in Disk Utility and was bootable. Have run Apple Hardware Test/Diagnostics but this returned no errors. It seems like a pretty clear cut case of drive failure.
I put this all to the relative whose laptop this is and asked them whether the MacBook had been dropped recently, explaining to them that this is one of the likeliest causes for such sudden failure. Sheepishly they admitted that they had indeed dropped it, although not from too great a distance and onto a carpeted floor. Apparently in the days immediately after the shock the hard drive continued to boot but the system was very slow and beset by spinning beech ball hangups. It is only in the last few days that the hard drive has become completely unbootable, and seemingly unreachable.
I have two questions that I would be grateful for some help with.
Firstly, is there any possibility of recovering data from this drive without going to a data recovery specialist? The user did have backups of most important data, but some recently imported photos were not backed up. Is it any use me trying any third-party data recovery software utilities, bearing in mind that I can't even mount the drive in target mode?
Second, the MacBook is still covered by the extended AppleCare warranty for the next two years. Is it worth my relative's while making a Genius Bar appointment to see whether Apple would replace this drive for free, given that the damage was most likely user-inflicted? Is there any chance that this sudden failure could be unrelated to the drop the MacBook suffered the other day - perhaps just a result of the 'normal' failure rate? I am more than happy to exchange the drive for a new one myself and my relative is happy to pay for the new part (I was amazed at how cheap hard drives are now), but would we be better off trying an Apple Store? My prediction would be that while we might get lucky and have an obliging genius who agrees to swap the drive without asking too many questions, we could also have one who concludes the damage is not covered by the warranty and insists on charging for the new hard drive (at a mark-up I assume) and labour.
Any thoughts about these two issues or the hard drive failure more generally are very welcome. Thanks.

1, Data recovery software is your only alternative if there is no backup. It may or may not be able to revoker anything from that hard drive. If it does then the only other choice is to go to a data recovery service. If have to go that route expect to pay for it, like $$$$.
2, Yes. They will at least tell him what the problem is and the cost if any to fix. There is a good chance they will fix it for nothing and only charge for data recovery if they can do it.

System failure/Logic - data recovery ideas?

I recently had a system failure of Mac os 10.4. A black box appeared on my MacBook instructing me to shut down via hard boot. When I fired the system back up an icon appeared, file with question mark, and computer was unresponsive.
I brought the MacBook in to Apple store and they attempted the disk utility and to re-install os to no avail. The files all seemed to be in place, and my personal files seemed to have volume, although not accessible In the end, the hard drive was replaced. The hard drive physically is ok, they described it as a logic failure. I brought the hard drive to Digital Medix to have my personal files recovered - when they performed a raw data recovery, only the system files were recovered - not my personal files.
The only thing I can think of is that I did enable data encryption via FileVault. Any ideas?

You could try the free demo of DataRescuell .
If the demo "sees" your stuff, you can purchase the full version to rescue the bigger files.
 Cheers! DALE

Enterprise server data recovery

A database server took a pretty rough hit oct 31 and we have been trying to recover the files that were stored there for three weeks. The trn logs and database only date back to December of 2013, we haven't been able to find anything from January
2014 till now.
I have search all drives and back ups but to no avail. Is there anyway to recover data lost from this year.

Hi Jemell,
Are you talking about SQL Server database or Windows Server (Any editions)? Regardless of your situation, there are only few things you can do to restore your valuable data yourself, either perform recovery through recovery software or send it across for professional
data recovery services.
See if any data recovery software can do the needful. As it seems that stored server data is crucial for you, I can recommend few most popular recovery software and want you to have a look:
Acronis Backup Advanced suite and
Stellar Data Recovery.
If you are still facing issues in looking for your desired data, consider sending it for professional data recovery services.
P.S. Stop using the drive immediately (saving any more data to the problem drive/server) and seek for professional help.
Do let us know about your progress.

IMAC Fusion Hard Drive failure, help with data recovery

I've got a Late 2012 iMAC 27 Inches 3.4GHZ with a Fusion 3.1TB HDD. My machine has booting issue the past few weeks and when contacted through Apple Care UK, after a few over the phone diagnostics they wanted me to take the machine over to get the Hard Drive checked. I had transferred some of my vital data from another HDD a few days before that and did not have an up to date backup. When booked in they said the HDD will have to be replaced and they will migrate the data over. But when I collected the machine, they said they couldn't transfer data as 'it didn't mount' and therefore unable to transfer. I was gutted as I have 2 wedding on their which were WIP and had to be delivered to the client in a few days. I have got my old HDD from the apple store...but unable to read data..can you help? Guess as a final resort I'd have to obtain the expensive data recovery services.

Ouch...
But before going for an expensive data recovery service, you have some other options.
At first you have to get that harddrive connected to your iMac. There are several solutions to that. One is to buy a SATA USB Docking Bay (see picture). You can put the harddisk in it and connect it via USB to your iMac.
Next you'll need recovery software. Disk Utility will probably not help you, but it is worth the try (because it is free and comes with OSX).
A great piece of software to look at is DiskWarrior. It once helped me accessing a dying External Harddisk and got most of the data off it before it really died. There are more applications, just google 'Data Recovery OSX', and you will find a lot more.
Oh, and make sure to start a good back-up plan for the future. Time Machine is great, or Carbon Copy Cloner, and maybe invest in a decent NAS to copy your data on.
Good luck!

Help! hard drive failure and data recovery

I am a happy PC-traitor who has been using my Macbook successfully for over a year now. I love the Mac.
Until now.
Last night, while downloading torrents onto my computer, it froze. I restarted. A blinking folder with a question mark was displayed. I tried resetting the PRAM. Disk Utility does not see my hard drive, so I cannot attempt to repair it.
In short, I think it's dead.
Disk recovery is so incredibly expensive! Can I stick the hard drive into an external housing and access the data via Firewire? Can I freeze it overnight? I'm desperate! I can't afford a data recovery service. Help!

If she's dead, she's dead. Could be a loose cable. If you boot from a DVD and DU can;t see the HD, that's usually a really bad sign.
If you are comfortable removing it, you can try something like
http://eshop.macsales.com/item/Newer%20Technology/U2NV2SPATA/
which will allow you to mount just about any HD via USB.
You can try stuff like
http://www.macintosh-data-recovery.com/download-mac-data-recovery.php
http://subrosasoft.com/OSXSoftware/index.php?mainpage=product_info&productsid=1
http://prosofteng.com/products/data_rescue.php
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Some of these may see HD's that won't mount and allow you to recover data.
Others may chime in with more detailed experiences.
hth
Jeff

ORA-01242: data file suffered media failure: database in NOARCHIVELOG mode

Hi All,
Need help from the gurus.
Currently we are in state unable to do anything.
Was using a database and all of a sudden it crashed. Tried to mount the database, open it, it failed. Also tried the recover and alter database open, even that failed. Errors are as follows.
Errors in file e:\oracle\product\10.2.0 \admin\devrevdb\bdump\devrevdb_p000_2620.trc:
ORA-00603: ORACLE server session terminated by fatal error
ORA-01242: data file suffered media failure: database in NOARCHIVELOG mode
ORA-00449: background process 'DBW0' unexpectedly terminated with error 1242
ORA-01242: data file suffered media failure: database in NOARCHIVELOG mode
In my spfile, the administrator has set only two control files and there is no mirroring and hence do not have another control file that will help me boot the db.
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Hemant,
thanks for the reply.
I tried the way you suggested and it threw an error.
ORA-01145: offline immediate disallowed unless media recovery enabled
I searched and found that an additional tag of drop needs to be added to the command which you suggested.
ALTER DATABASE DATAFILE '<filename>' OFFLINE DROP.
i don't know what will the drop command have an effect ?
i have copied the data file to another location. Since i don't know much, i just want to be sure of what im doing.
if the above command is successfull, will it drop the datafile or the tablespace and i can no more use it. How can i use the copied datafile.
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Sachin
I

Data Recovery Expert Needed

Do you know any experts on data recovery on a MacBook Pro?
Two catastrophic things happened:
- A user's FileVault encrypted .spareimage completely went away. I believe that there is some kind of major drive failure corruption that occurred.
- The user's Mobile Account was manually sync'd every day before she would go home. But unfortunately everything except for her /Library folder was getting sync'd with the Snow Leopard Server (also a bizarre misfortune).
Thus, she has lost all of her Sent mail and other local email folders that only resided on her laptop.
I can't even boot into the laptop anymore. We tried Firewire initially which showed an empty user folder...no .sparseimage to speak of in the /Users/username folder.
So I'm looking for a data recovery specialist that may be able to locate and resurrect the missing .sparseimage FileVault file. It's a longshot but would be worth it if successful.
Thanks!

http://support.apple.com/kb/HT2631

Using Bitlocker Data Recovery Agent (DRA) on Surface Pro 3

We currently have the Data Recovery Agent (DRA) configured in our Bitlocker Policy for our Windows 7 Systems, and it works fine. In situations where the Recovery Key for the computer object was not backed up to AD correctly for whatever reason or the computer
object was deleted, our HelpDesk can connect the encrypted drive to another system, and then use the certificate for the DRA to unlock the drive.
I'm wondering if the BitLocker DRA Certificate unlock method will work for Surface Pro 3 devices, in the case that that their computer object and normal BitLocker recovery key is deleted or missing in AD for whatever reason. Seeing as how our helpdesk can't
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noctlos wrote:
Using linux-3.18 and -3.19 kernels, with wayland/weston v. 1.7. In its own tty, i try to run weston, and I get the following stderr:
Could anyone help me to figure this out? Thanks.
Seems that the problem lies in libinput. Maybe you can report that upstream. I suggest you recompile libinput with debug info and do not strip the binaries to obtain better backtraces.
Edit:
I have also tried running `swc-launch -- velox`, and get the following error:
Running on /dev/tty2
velox: error while loading shared libraries: libinput.so.5: cannot open shared object file: No such file or directory
Server exited with status 127
Restoring VT to original state
So, perhaps I am having some libinput trouble. Does this seem correct?
Well, that's a different problem. libinput has several soname bumps because of API and ABI incompatibility. You have to rebuild swc against the newest libinput. (Although I'm not sure if swc developer updated the code to new API)
Edit 2:
Just to tack this on here for `gnome-session --session=gnome-wayland --debug`
I'm not expert on this, it may be related to libinput problem. If you don't include GDK_BACKEND=wayland environment variable when launching gnome-wayland.
Last edited by jdbrown (2015-03-01 08:04:39)

Data Recovery On an iBook G3

I had an iBook G3 in college (2002, exact model @ http://bit.ly/VGVpSh), and when it died I purchased a new Mac and shoved the iBook in a box (About 7 years ago). It died from the logic board/display issues that all those dual-USB iBooks had. I actually had one, or maybe even two, logic board(s) replaced under warranty, but it eventually went out again, and I just bought a whole new laptop. I know I have a ton of photos from college on there, and that's really the data I'm now after! I can get the screen to work most of the time by placing a clamp under the 'Option' key on the left half of the keyboard. New problem though, as fired it up to take a stab at finding my data; I'm getting a flashing question mark when it boots up, which a little research shows is indicative of hard drive failure... My photos!!! So I've messed around with the computer for an hour or so, and haven't had any luck.
First and foremost, does the flashing question mark mean that data's dead and gone for good, period? Or could the drive itself be fine, but the controller/cables be bad? Sadly, ten years later I don't have the install CD, so that's not an option. I used a random OS9 disc I found online, but it wouldn't boot off that either; I'm guessing because it's not the original OS CD for this model... I also can't get the 'Firewire target' to work. The oldest computer I have in the house is an Intel 2ghz core duo 2 (exact machine @ http://bit.ly/LqDkzw) running 10.6. I'm guessing the new machine/OS won't do the Firewire target mode, as I've been unsuccessful when I've tried. I just read there are different Firewire 400 vs Firewire 800 cables, so I guess I could just be using the wrong cable as well..? I found an old Firewire cable to even try this in the first place, but I have no idea if it's 400 vs 800. Or would a bad hard drive preclude the Firewire target mode anyway?
I've also tried random things like Ethernet connections, but no luck. I'm guessing the probably-wide OS gap won't allow them to communicate anyway.
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I use the external caddy as edex67 has suggested you try. This is probably the cheapest and easiest way to recover the pics providing that the hard drive is working. The only catch is you must remove the drive in order to attach to the adapter. Since you are not trying to resurect the iBook, the drive removal would be easier as disassembly would not have to be as cautious. Below links to disassembly and a source for an adapter.
http://www.ifixit.com/Device/iBook_G3_12%22
http://eshop.macsales.com/item/NewerTech/U3NVSPATA/

DATA RECOVERY for a hard drive that isn't recognized.

Hi,
I just found today that my hard drive is bad. I had one of those geek squad people come look at it and he was able to get it to boot from the Mac OS X Leopard CD, but my hard drive was no where to be seen.
I'm taking the hard drive to one of those places that specializes in data recovery. But, I was wondering...can they retrieve files that were on the desktop? Or are those files gone forever?

Hello Again! Now that there is serious soul searching going on now would be a good time to think about your backup plans for when you get everything up and running again. If the drive is going off to the recovery center worrying further won't help so I suggest coming up with a good recovery plan for times like these. Hard drives are going to fail and they always seem to fail at the most inopertune times but with a good backup plan this could have only been a restart. A second hard drive is a must if there is anything at all important on the computer. It can be an external or internal. I have 4 320 gig SATA drives in my G4 (and I really don't have anything very important on there) I usually keep two secondary bootable clones and rotate between them in case of a backup failure. Then I try to keep another clone on an external and finally I keep a partition with only a fresh install and my utilities for drive repair. I tinker a lot and I've screwed things up a few times but it really wasn't even a minor irritation. Good luck. Tom

Data recovery on server failure

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