Re: [Discuss] Backing up LVM partitions using snapshots
On 12/13/2011 11:11 PM, ma...@mohawksoft.com wrote: On 12/12/2011 10:39 PM, ma...@mohawksoft.com wrote: Why would that happen? That's what I don't understand. If you have a mission critical failure of this sort, then you fall back to a previous backup as your beginning and do a full backup at this point. You don't ignore the failure and proceed business as usual. Follow closely: * Create file #1 * Do full dump. Contains file #1 data and directory metadata. * Create file #2. * Do incremental dump #1. Contains file #1 directory metadata, file #2 data and directory metadata. * Create file #3. * Make incremental dump #2. Contains file #1 and #2 directory metadata, file #3 data and metadata. * Disaster strikes! The server explodes in a ball of flame, or gets eaten by Gojira or something. You replace the hardware and prepare for recovery. OK. * Restore full dump to new server. You now have file #1 complete. * Attempt to restore incremental dump #1 and find that it is unusable. Using a block level store, an incremental backup is no different than a full backup. It appears that you are thinking of using tape or something. tape is dead. The backup medium is a combination of RAID and/or cloud. With block level differential backup, you can effectively replicate a volume with a minute amount of data. There are many levels of disaster, if just the data volume is lost, then it can be restored in full from any of the successful backups. if it is a site level disaster, then you get your backup data from offsite or cloud. I worked at a tape backup company years ago working with the QIC and DAT formats. OMG what a disaster. Disk sectors are cheaper and more reliable. I've also had my issues with tape. (1) back on mainframe systems in the early 70s, I had the tape drive burn a hole in a tape. (2) At home years ago, I needed to restore my file system, and the tape system was simply dead. I think I might have had write-only tapes :-). At that time, I also had a Jaz drive with a recent backup. A few weeks ago, I got email from the IT guy in New York looking for $1000 worth of tapes he ordered. For some reason they were sent to me. I work in a Regus Office (eg. HQ company)., I never saw the tapes but they were signed for by the center manager. 6 weeks later I got a call from the receptionist that one of the clients had a box addressed to me. It was the tapes. The bottom line is that there is no backup medium that is safe.. All media degrade over time. A local RAID is good, but one lightning strike of other glitch can render the drives dead. A cloud is probably the best solution since it is actively managed, but you have to trust the cloud provider, (1) to maintain the integrity of your data, and (2) the security of your data. -- Jerry Feldman g...@blu.org Boston Linux and Unix PGP key id:3BC1EB90 PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66 C0AF 7CEA 30FC 3BC1 EB90 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Backing up LVM partitions using snapshots
The bottom line is that there is no backup medium that is safe.. All media degrade over time. A local RAID is good, but one lightning strike of other glitch can render the drives dead. A cloud is probably the best solution since it is actively managed, but you have to trust the cloud provider, (1) to maintain the integrity of your data, and (2) the security of your data. The two backups rule address issue #1, yea, I know, even double redundancy will fail eventually. Life is risk. http://www.mohawksoft.org/?q=node/83 As for item #2, I actually take care of that. By compressing and encrypting PRIOR to uploading to the cloud, there's no way any interested party can see your data without your password in a reasonable amount of time given the current level of computing power. -- Jerry Feldman g...@blu.org Boston Linux and Unix PGP key id:3BC1EB90 PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66 C0AF 7CEA 30FC 3BC1 EB90 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Backing up LVM partitions using snapshots
On 12/14/2011 08:14 AM, ma...@mohawksoft.com wrote: The bottom line is that there is no backup medium that is safe.. All media degrade over time. A local RAID is good, but one lightning strike of other glitch can render the drives dead. A cloud is probably the best solution since it is actively managed, but you have to trust the cloud provider, (1) to maintain the integrity of your data, and (2) the security of your data. The two backups rule address issue #1, yea, I know, even double redundancy will fail eventually. Life is risk. http://www.mohawksoft.org/?q=node/83 As for item #2, I actually take care of that. By compressing and encrypting PRIOR to uploading to the cloud, there's no way any interested party can see your data without your password in a reasonable amount of time given the current level of computing power. You are quite right. Chevron had a pretty decent disaster recovery system, but during Katrina they lost their primary and secondary data centers. -- Jerry Feldman g...@blu.org Boston Linux and Unix PGP key id:3BC1EB90 PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66 C0AF 7CEA 30FC 3BC1 EB90 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
[Discuss] [OT] Asset Management
As I know many of you manage a lot of the equipment and things that go through your office I was wondering if anyone could assist. Currently at my company we do an awful job of managing everything from software to machines we hand out to users. I suggested to one of my managers that we should really review our Asset management, well they decided to play a sick joke and put me in charge of it. Does anyone know of any resources that I could leverage to at least get started on this. Books or anything at all would be useful. I know the first problem always starts with getting the people to do the right thing but we are a small team and I am sure bad habits can be changed. As an example of a bad process (I think), we currently name our end-user machines after the person receiving it. Ie. BOS-KLESLIE, we run in to trouble with this in many areas but its just something I think is not a good way of doing things, for various reasons. 1 Major one is If we have to deploy a new machine to them (many/most remotely) we have to name the second machine BOS-KLESLIE2 then retrieve the old machine remove it from the domain and rename the newly deployed. Well, when I came to this company we have machine names like BOS-KLESLIE5. Quite frustrating when you don't know if 1-5 have returned. Any suggestions at all would be useful. We currently have software to do this (Track-IT) but if people have good suggestions I am open to those as well. TIA. Kyle ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] [OT] Asset Management
On 12/14/2011 9:04 AM, Kyle Leslie wrote: As I know many of you manage a lot of the equipment and things that go through your office I was wondering if anyone could assist. Currently at my company we do an awful job of managing everything from software to machines we hand out to users. I suggested to one of my managers that we should really review our Asset management, well they decided to play a sick joke and put me in charge of it. Does anyone know of any resources that I could leverage to at least get started on this. Books or anything at all would be useful. I feel your pain. A few years ago, when I was a programmer at NYNEX, I made the mistake of opening the boxes that arrived with our new computers inside them, and I was instantly appointed as the computer guy and forced to carry them on a cord around my neck forever. I know the first problem always starts with getting the people to do the right thing but we are a small team and I am sure bad habits can be changed. Oh, you innocent child. You are about to get a rude lesson in human nature. They won't change. They won't tell you that they won't change, but they still won't change. As an example of a bad process (I think), we currently name our end-user machines after the person receiving it. Ie. BOS-KLESLIE, we run in to trouble with this in many areas but its just something I think is not a good way of doing things, for various reasons. 1 Major one is If we have to deploy a new machine to them (many/most remotely) we have to name the second machine BOS-KLESLIE2 then retrieve the old machine remove it from the domain and rename the newly deployed. Well, when I came to this company we have machine names like BOS-KLESLIE5. Quite frustrating when you don't know if 1-5 have returned. That's not going to work. There is a reason that /people/ have social-security numbers: /people/ have very redundant and confusing names. /Computers/ need unique identifiers too, which must not be associated with any one person. It's sometimes handy to have location-specific names, but if your company has a central maintenance facility or other swap shop, the id codes should be generic: when you put someone's name on a device, you award them ownership and make that device a part of their status. A random number won't be associated with anything but what it /is/, and that's a tool that anyone can use, no different than the copy machine or the fax machine or the phone that looks like every other phone. Any suggestions at all would be useful. We currently have software to do this (Track-IT) but if people have good suggestions I am open to those as well. In no particular order, my suggestions: 1. Keep your sense of humor. You'll find that laptops, printers, cell phones, etc., will wander across the corporate culture according to social and professional affiliations that you can only guess at: the does everything expensive laptop will wind up in the hands of a low-level staffer, who traded her limited-function workstation to the boss, because the boss wanted something lighter to carry on the plane. The multi-color laser that was spozed to be in use in the graphics department will mysteriously wind up next to the Vice-President's secretary, and the graphics department will be putting in requisitions for more and more ink cartridges no matter how much you think they should get the laser back. Employees will trade cell phones at dizzying speed, every time they want to ditch a boyfriend or lose their spouse for a day. 2. Simplify everything you can, as much as you can. If you have a single brand for all computers, e.g., Dell, then you can use Dell's software to keep track of the machines. Even if not, most computer BIOS chips allow you to add asset tags that can be locked out from changes, so that you can keep track of them either locally or remotely, depending on which inventory package you have available. 3. Be very careful how much data you gather. If you keep, as I once did, the records of logins by machine and location, you will find some amazing and disturbing coincidences that can start you wondering how the middle-managers in your company manage to stay either married or out of jail. Trust me: sometimes, ignorance /is/ bliss: so long as you're reasonably sure that a given machine is still in the hands of a corporate employee, you've done your job. 4. Remember that you're fulfilling a corporate need, and that is that managers want someone to be accountable. Be sure that portable devices have good spill/drop/theft insurance, that source CD's are always accounted for (I always burned copies and gave them out instead of the originals), and that you have a no big deal speech on hand when someone arrives in a panic because their laptop is on it's way to Jamaica-the-country instead of Jamaica-in-Queens. Your most important asset is your attitude, and you must project a takes-it-in-stride sensibility
Re: [Discuss] Backing up LVM partitions using snapshots
On Dec 13, 2011, at 11:11 PM, ma...@mohawksoft.com wrote: Using a block level store, an incremental backup is no different than a full backup. You're not following me. You have a full dump. You have a first differential against that dump. You have a second differential made against the first differential. If you lose the first differential then you are screwed. A way to work around this is to make your second differential against the full dump rather than against the first differential. In this case, loss of the first differential is not a disaster. On the other hand, a file system with a high churn rate, like a mail spool or data collection volume, is eventually going to have differentials nearly as large as the data itself, at which point it will be no better than a file system dump as far as efficiency is concerned. It will, however, be worse in terms of recovery since it can't be used to restore arbitrary files. The whole dump chain needs to be unwound -- and that's a lot of time for a 16TB volume. It appears that you are thinking of using tape or something. tape is dead. The backup medium is a combination of RAID and/or cloud. [expletive deleted]. Cloud storage is unreliable. If your provider is down then your backups are unavailable. If your provider goes out of business then your backups are *gone*. A RAID cage in your or your cloud storage's data center isn't proof against a flood or fire. Tape is slow and cumbersome and costly but it still beats everything else for archival storage. If it were otherwise then we'd have long since abandoned magtape for any of the plethora of other tape killer technologies that have come done the 'pike. Remember when CD-R was going to make tape obsolete? Remember when MO media like DVD-RAM was going to make tape obsolete? Remember when DVD-R was going to make tape obsolete? None of these are widely used for large scale (enterprise) backups. What do we use? Magnetic tape. We use disk-based archives for quick recovery, but our long-term archives are on magnetic tape -- at least, they are in the real world. ObTechnialPoint: /dev/st0 is a block device. It's a sequential access block device rather than a random access block device, but it's still a block device. --Rich P. ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
[Discuss] [OT] Google+
I keep getting a Google+ message on my phone name mentioned you in a post I can find no way either on my phone or online via the web interface. The issue is that it is the same post from 2 days ago. On the Android I have a Mute or abuse, and it is not abuse, and I'll slug the guy next Wednesday. I have not removed him from my circle yet. Anyone have an idea how to keep this from popping up every few hours (or less). -- Jerry Feldman g...@blu.org Boston Linux and Unix PGP key id:3BC1EB90 PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66 C0AF 7CEA 30FC 3BC1 EB90 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Backing up LVM partitions using snapshots
On Wed, Dec 14, 2011 at 10:53 AM, Richard Pieri richard.pi...@gmail.com wrote: On Dec 13, 2011, at 11:11 PM, ma...@mohawksoft.com wrote: Using a block level store, an incremental backup is no different than a full backup. You're not following me. You have a full dump. You have a first differential against that dump. You have a second differential made against the first differential. If you lose the first differential then you are screwed. I've been watching the (second?) incarnation of this thread for a while now and I think that I see your point. I wonder if the TRIM functionality that is being added to filesystems in order to handle SSDs could help with this. Filesystems with high churn rates are likely to see lots of data blocks (but probably not meta-data blocks) get TRIMmed. If snapshots kept track of this in some fashion it might become cheap enough to just do differentials against the original full dump rather then against earlier differentials. This would seem to substantially reduce your concerns about data loss. This wouldn't help with single file restore although file level backup systems that do incremental backups can require you to go through a pile of tapes unless they keep a database of filenames/versions/tapes. Does anybody know if LVM pays attention to TRIMs at all? At this point, this is idle speculation on my part. I haven't researched or thought it through. Bill Bogstad ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Backing up LVM partitions using snapshots
On Wed, December 14, 2011 2:00 pm, Richard Pieri wrote: On 12/14/2011 12:34 PM, Bill Bogstad wrote: I've been watching the (second?) incarnation of this thread for a while now and I think that I see your point. I wonder if the TRIM functionality that is being added to filesystems in order to handle SSDs could help with this. I don't think so. The problem I describe is that once a dump goes missing then any differentials against it will have inconsistencies between the file data and the file metadata structures. TRIMming freed blocks won't make this go away. It might make things worse what with dangling inode lists pointing to de-allocated SSD blocks. As an aside, enterprise backup systems like Amanda and Bacula and TSM do, indeed, maintain databases of backed up files and what media they are on. This is also the reasoning why you should perform regular full dumps, because it resets the history necessary to perform a backup. For example, you could perform monthly full backups, then weekly incrementals, and then daily incrementals off the weekly incrementals. So worst case you need 11 restores to get to any point in time (full, 4xweekly incremental, 6 daily incrementals off the weekly). There are many other strategies that you can use, but yes, if you lose an intermediary incremental then yes, you've effectively lost everything that happened after that, until your next higher-level (or lower-level, depending which way you look at it) dump. E.g., if in the above scenario you lose a daily incremental then you lose all data for the rest of the week, whereas if you lose a weekly incremental then you lose all data for the rest of the month. -derek -- Derek Atkins 617-623-3745 de...@ihtfp.com www.ihtfp.com Computer and Internet Security Consultant ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Backing up LVM partitions using snapshots
On Wed, Dec 14, 2011 at 2:00 PM, Richard Pieri richard.pi...@gmail.comwrote: On 12/14/2011 12:34 PM, Bill Bogstad wrote: I've been watching the (second?) incarnation of this thread for a while now and I think that I see your point. I wonder if the TRIM functionality that is being added to filesystems in order to handle SSDs could help with this. I don't think so. The problem I describe is that once a dump goes missing then any differentials against it will have inconsistencies between the file data and the file metadata structures. TRIMming freed blocks won't make this go away. It might make things worse what with dangling inode lists pointing to de-allocated SSD blocks. As an aside, enterprise backup systems like Amanda and Bacula and TSM do, indeed, maintain databases of backed up files and what media they are on. __**_ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/**listinfo/discusshttp://lists.blu.org/mailman/listinfo/discuss Correct me if I'm wrong, but I thought differentials are a backup of all things that have changed since the last full. Incrementals are changes since the last incremental, differential or full, whichever happened last. For example one my SQL Servers has a schedule that is a full once per week (wednesday's), a differential every night (except wednesday), then incrementals every 10 minutes. If I want to restore up to this past Monday at 9AM I would take the full from last wednesday, then the differential from Sunday night/Monday morning, then I would apply all incrementals from the time of the differential up to 9AM on Monday. What I don't have to do is apply every differential (Thursday, Friday, Saturday Sunday). Also, I believe I mentioned this in the last LVM discussion. When you snapshot LVM it does not make a copy of the original content. It marks all blocks in that original volume as read-only until the snapshot is released. Any new writes to either the original volume or the newly created snapshot happen in the scratch space. You can take as many snapshots as long as you monitor your scratch space to make sure it's not filled up. During a snapshot whether you access the original volume (+ changes) or the snapshot (+changes) it is on the fly deciding to pull blocks from the original volume and the scratch space to recreate what you're asking for. One thing to keep in mind when using snapshots is if your scratch space goes to 100%, then all snapshots are released and all changes to the original volume (which up to this point are being held in scratch space) are written back to the original volume. Allocating scratch space is done by not assigning to any logical volumes, and deciding how much to allocate is hugely dependent on amount of changes to your data over the amount of time that you keep your snapshots online and the number of snapshots and whether or not you also modify your snapshots. I've always told people if you don't have time to build, test, rebuild until you get it right, then just overallocate. Now, some cool tricks you can do with LVM are adding more drives to your volume and growing your volume on the fly. If you decide that you want to go from a 500GB volume to a 1TB volume, you can do an add and migrate of your data. All new data will be written to the new drive and during idle time blocks on your old drive will be migrated to the new volume. Once data is off your old volume it can be removed from the group and removed. Matthew Shields Owner BeanTown Host - Web Hosting, Domain Names, Dedicated Servers, Colocation, Managed Services www.beantownhost.com www.sysadminvalley.com www.jeeprally.com Like us on Facebook http://www.facebook.com/beantownhost Follow us on Twitter https://twitter.com/#!/beantownhost ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] [OT] Google+
In Google+, click on the gear icon in the upper right corner and select Google+ Settings. There's a big section for setting what kinds of notifications you want to receive. You should be able to shut off the ones that are bothering you. On Wed, Dec 14, 2011 at 12:34 PM, Jerry Feldman g...@blu.org wrote: I keep getting a Google+ message on my phone name mentioned you in a post I can find no way either on my phone or online via the web interface. The issue is that it is the same post from 2 days ago. On the Android I have a Mute or abuse, and it is not abuse, and I'll slug the guy next Wednesday. I have not removed him from my circle yet. Anyone have an idea how to keep this from popping up every few hours (or less). -- Jerry Feldman g...@blu.org Boston Linux and Unix PGP key id:3BC1EB90 PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66 C0AF 7CEA 30FC 3BC1 EB90 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss -- John Abreau / Executive Director, Boston Linux Unix OLD GnuPG KeyID: D5C7B5D9 / Email: abre...@gmail.com OLD GnuPG FP: 72 FB 39 4F 3C 3B D6 5B E0 C8 5A 6E F1 2C BE 99 2011 PGP KeyID: 32A492D8 / Email: abre...@gmail.com 2011 PGP FP: 7834 AEC2 EFA3 565C A4B6 9BA4 0ACB AD85 32A4 92D8 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Backing up LVM partitions using snapshots
On 12/14/2011 2:21 PM, Matt Shields wrote: Correct me if I'm wrong, but I thought differentials are a backup of all things that have changed since the last full. Incrementals are changes since the last incremental, differential or full, whichever happened last. This is correct. Keep in mind that Mark's method includes directory metadata blocks. If I create a file then the directory blocks for all of the files in that directory will be marked changed along with the file data blocks. This is what complicates things. LVM doesn't know the difference between file data blocks and file metadata blocks. It's just blocks to LVM. ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Off-Topic [IP] BufferBloat: What's Wrong with the Internet?
Rich Braun wrote: Bill Horne: At some point, the Internet will need a major overhaul. Will it? I think we have a very long history of incremental tweaks ahead of us... For what common carriers are trying to do...TCP/IP can't be made to fit. I'd buy that TCP may not be part of the future for real-time communications - heck, it hardly is now, given that Skype, SIP, RTP are all UDP - but I think what you intended is that the packet-switched infrastructure used by IP isn't workable. On that I disagree, as the desire to provide super cheap communications is too great. Unless a cheaper alternative comes along for the OSI layer 2 and 3 infrastructure[1] we currently have, we'll see creative solutions at layer 4 (TCP, UDP, SCTP[2]), or just faster pipes, as Rich suggests - whatever ends up being cheaper to implement. 1. http://en.wikipedia.org/wiki/OSI_model#Layer_3:_network_layer 2. http://en.wikipedia.org/wiki/Stream_Control_Transmission_Protocol Providers are currently racing at breakneck speed towards zero cost telecommunications. Consider Google Voice, or Republic Wireless (whose parent, Bandwidth.com, provides the infrastructure for Google Voice, Skype, etc.), which obtained its own country code so your friends and family in other countries can call your Republic Wireless phone for free[3]. 3. http://techcrunch.com/2011/12/13/republic-wireless-is-launching-free-international-calling-powered-by-their-own-country-code/ As phone service becomes like a disposable commodity, people will be more tolerant of reliability problems, and likely will have a variety of alternate channels to choose from if one doesn't work to their liking at the moment. Also consider that many of us are increasingly using less and less real-time communications. Replacing phone calls with text messages and IMs. This fight will be about which mega-corporations carve out virtual slices of Internet bandwidth so that they can avoid paying for their own. There will likely emerge premium services that give you guaranteed latency, using things like RSVP[4] or NSIS[5], but I think the vast majority of users will find the commodity service to be good enough. 4. http://en.wikipedia.org/wiki/Resource_reservation_protocol 5. http://en.wikipedia.org/wiki/Next_Steps_in_Signaling The gearheads who recognize BufferBloat will ultimately do the obvious: crank down the buffering and adjust the retry parameters. And flatten out the number of hops from source to destination. Right. [Thanks to Stephen Ronan for sharing the article. I'd heard about this buffer bloat issue before, but hadn't read the details.] -Tom -- Tom Metro Venture Logic, Newton, MA, USA Enterprise solutions through open source. Professional Profile: http://tmetro.venturelogic.com/ ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] [OT] Google+
I have no problem turning off notifications, or notifications when I am mentioned. But I don't see how I can turn off once I receive the notification. What I am getting is a notification of the same event over and over again. On 12/14/2011 02:35 PM, John Abreau wrote: In Google+, click on the gear icon in the upper right corner and select Google+ Settings. There's a big section for setting what kinds of notifications you want to receive. You should be able to shut off the ones that are bothering you. On Wed, Dec 14, 2011 at 12:34 PM, Jerry Feldman g...@blu.org wrote: I keep getting a Google+ message on my phone name mentioned you in a post I can find no way either on my phone or online via the web interface. The issue is that it is the same post from 2 days ago. On the Android I have a Mute or abuse, and it is not abuse, and I'll slug the guy next Wednesday. I have not removed him from my circle yet. Anyone have an idea how to keep this from popping up every few hours (or less). -- Jerry Feldman g...@blu.org Boston Linux and Unix PGP key id:3BC1EB90 PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66 C0AF 7CEA 30FC 3BC1 EB90 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Backing up LVM partitions using snapshots
From: discuss-bounces+blu=nedharvey@blu.org [mailto:discuss- bounces+blu=nedharvey@blu.org] On Behalf Of Bill Bogstad On Wed, Dec 14, 2011 at 10:53 AM, Richard Pieri richard.pi...@gmail.com wrote: On Dec 13, 2011, at 11:11 PM, ma...@mohawksoft.com wrote: Using a block level store, an incremental backup is no different than a full backup. You're not following me. You have a full dump. You have a first differential against that dump. You have a second differential made against the first differential. If you lose the first differential then you are screwed. I've been watching the (second?) incarnation of this thread for a while now and I think that I see your point. That's not how incremental snapshots work. Well sure, if you leave these datastreams laying around as files, then the argument is true, lose the first incremental and you lose everything after it. But that's not what you do. I can't speak on behalf of Mark's stuff, but there is only one sane way to behave: You receive your first complete image. In and of itself, it represents a filesystem. On the receiving end, you snapshot the receiving filesystem. You send an incremental datastream, and write it directly on top of the recipient filesystem. After this receive is completed, it represents a whole filesystem. Optionally delete the previous snapshot on the recipient system. You send another incremental datastream, and so on. At all times, you have a complete filesystem. You never have any incrementals laying around, waiting for corruption to silently occur. You're not writing them to tape and sending them to the vault. Every time you receive an incremental image, it's written directly on top of the previously received image. ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] [OT] Google+
Apparently this is a phone setting, not a googleplus setting. Here are the instructions for an iPhone; maybe it will help you find the equivalent instructions for Android. https://plus.google.com/109932063492318931033/posts/J8um5cjSxPA On Wed, Dec 14, 2011 at 4:28 PM, Jerry Feldman g...@blu.org wrote: I have no problem turning off notifications, or notifications when I am mentioned. But I don't see how I can turn off once I receive the notification. What I am getting is a notification of the same event over and over again. On 12/14/2011 02:35 PM, John Abreau wrote: In Google+, click on the gear icon in the upper right corner and select Google+ Settings. There's a big section for setting what kinds of notifications you want to receive. You should be able to shut off the ones that are bothering you. On Wed, Dec 14, 2011 at 12:34 PM, Jerry Feldman g...@blu.org wrote: I keep getting a Google+ message on my phone name mentioned you in a post I can find no way either on my phone or online via the web interface. The issue is that it is the same post from 2 days ago. On the Android I have a Mute or abuse, and it is not abuse, and I'll slug the guy next Wednesday. I have not removed him from my circle yet. Anyone have an idea how to keep this from popping up every few hours (or less). -- Jerry Feldman g...@blu.org Boston Linux and Unix PGP key id:3BC1EB90 PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66 C0AF 7CEA 30FC 3BC1 EB90 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss -- John Abreau / Executive Director, Boston Linux Unix OLD GnuPG KeyID: D5C7B5D9 / Email: abre...@gmail.com OLD GnuPG FP: 72 FB 39 4F 3C 3B D6 5B E0 C8 5A 6E F1 2C BE 99 2011 PGP KeyID: 32A492D8 / Email: abre...@gmail.com 2011 PGP FP: 7834 AEC2 EFA3 565C A4B6 9BA4 0ACB AD85 32A4 92D8 ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
[Discuss] forward of a gadget idea
Don't know the guy/gal who posted this to another list I'm on, just thought perhaps someone here might appreciate it. Sorry for bandwidth consumption. --- Forwarded Message Date: Wed, 14 Dec 2011 00:47:02 -0800 From: A.Lizard aliz...@ecis.com Subject: a trivial device, but I think, a useful one I filed a patent application for an electronic gadget a few months ago. Those of you who do your own computer maintenance and upgrades know how much crap builds up inside a computer sucked in by the fans. While one can get computer air filters at larger electronics retail stores, forgetting to clean the filter turn a recurring annoyance into a much bigger problem when the CPU can't get any cool exterior air. I also discovered in the course of working on this that just because an open-cell foam filter looks clean doesn't necessarily mean that it is. The fix is a computer filter monitoring device, you can see it at http://www.computerfiltermonitor.com . I wash out the filter when the software alarm tells me to and don't think about it otherwise. My computer stays both internally clean and cool. At the moment, the only available form is a bare PCB with user guide and assembly instructions, I'm looking for an OEM. I figure that some of you might find this useful (I designed it because I wanted one and nobody sells anything like it that actually works) and because I figure that anyone who reads this list is up to PCB assembly. It took me a while to get around to mentioning this largely because there was a design error in the first PCB and I wanted to make sure the bug was stomped out before announcing it. I figure the people who can really use this are ones who spend a lot of time working on their computers and the ones whose computers *must* work *all* the time. While this won't guarantee that since AFAIK, there is no way to guarantee 100% computer uptime, it's one variable that can be put under one's control. A.Lizard -- member The Internet Society (ISOC), The HTML Writers Guild. All that is, is information Personal Website http://www.ecis.com/~alizard business Website http://www.reptilelabs.com backup address (if ALL else fails) aliz...@gmail.com PGP 8.0 key available by request or keyserver. Download PGP from: http://www.pgpi.org for e-mail privacy. Disaster prep info: http://www.ecis.com/~alizard/y2k.html ***Looking for INTELLIGENT new technology public policy alternatives?*** http://www.ecis.com/~alizard/technology.html --- End of Forwarded Message ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
Re: [Discuss] Backing up LVM partitions using snapshots
On Dec 14, 2011, at 4:56 PM, Bill Bogstad wrote: Let me try again. 1. Do away with differentials against differentials. 2. Optimize differential against full by keeping track of TRIMs so that writes that are later TRIMed are dropped from the list of differences from full. Since any restore would be simply full + one differential there shouldn't be any inconsistencies. I now see that #1 is a given -- and something that needs to be well-documented, with eight-by-ten colour glossy photographs with circles and arrows and a paragraph on the back of each one explaining what each one was. While incremental against incremental is perfectly fine for file-level backups, it looks to be a disastrous mistake for block-level dumps. So... what happens if you lose a full dump? Suppose a 7 day cycle. Do a full dump (f1), then six differential dumps (d1.1-d1.6). Then do a second full dump (f2), and start doing six more differentials, but disaster hits on day 4 so you have only 3 days of differential dumps (d2.1-d2.3). You go to restore f2 and discover that it is corrupted, unusable, maybe LVM reaped it. Okay, go back to f1 and restore, then restore d1.6. That gets the volume to the state it was a day before the f2 dump was made. What now? #2 should work, but I don't know enough about various TRIM implementations to say with certainty either way. I still see the potential security issue with reused blocks. TRIMed blocks aren't zeroed and they will be reallocated for use. This could be exploited. Been there, done that. Of course, when that database gets corrupted recovering even a single file from a file oriented backup system means you start scanning a bunch of tapes. Some systems like to backup the database every time any kind of backup occurs. Been there, done that, hate Legato Networker for it because back in the day it *didn't* back up it's own database. This can get expensive if you have lots of small files or you keep your history for a long time. Now... this statement bothers me on a fundamental level. It's the negative perception that backup systems are expensive. Your data has value. Will losing that data cost you more than what it would cost you to have a reliable backup? If the answer to that question is yes then the backup system isn't expensive in relation to the value of the data it stores. It may have a high monetary cost (FSVO high), but if it lets you recover from a disaster then it saves you more money than it costs. Thus, it is not expensive. --Rich P. ___ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss
