Confused about Disk Media Sets/Members

[kmpeterson]

I may not be the only one here... but...

 

I'm using Disk Media Sets, with a CIFS share on a Linux server as the destination. Backups seem to run fine.

 

In the v6 days, I used ftp backup support to the same server. I generally wanted to keep my "time to restore" down to a minimum, and some history, by using "New Media Backups".

 

I thought I could do the same with v8, but I guess I'm confused about the options available. I had created a new "media set" but had assumed that a "member" was effectively the same as a backup set with respect to rotation.

 

So, I'm in a situation where I asked for a backup (after a period of time) to "skip to a new member". I had noticed that the destination for the media set (mounted as /volumes/Backup) was (on the server) /Backup/Retrospect/SETNAME/1-SETNAME - which looked like how v6 named backup sets. So, I expected that when I asked for "skip to a new member", that Retrospect v8 would create /Backup/Retrospect/SETNAME/2-SETNAME - and happily perform a "full" backup there.

 

Should I be surprised this isn't happening?

 

What does happen is that Retrospect stops, and wants to know what media to use. If I select /Backup, it tells me that this is already part of the backup set. Well, of course. I wanted a new member - in the same backup set.

 

Like I said, I must be confused.

 

What I'm trying to do is to be able to move the previous member(s) offline. My reasoning is that I want to keep some backup copies for a longer period of time, but not online, so let me put them somewhere else.

 

I'm trying to protect against deletions or file corruption that may not have been noticed for some period of time; keeping 90 days of backups online is fine but I don't want exposure to problems not caught before then.

 

I should also point out that I have not yet successfully been able to groom a media set. I'm currently working with about 400GB of data, but haven't actually seen a grooming job complete successfully yet (and 3-4 days is a long time to have Retrospect sitting there chewing over its catalog).

 

So, my questions are:

 

1. If I want to get a new, full backup, automatically, how would I do this? Skip to new member doesn't seem to work how I expect. Start new media set seems like it would require manual intervention ("create a new media set"?) that I'd like to avoid.

 

2. Should I consider a Copy job instead, then recycle the media set? Can I chain these two events somehow?

 

3. Is there some other design goal that I'm missing that would satisfy my needs without jumping through any hoops suggested by answers to 1. or 2.?

 

4. If I say, for a media set, "keep 30 days" worth of backups, for a media set with 400GB, and enable grooming, should it take 3-4 days and have problems completing successfully? If so, can anyone point out what I might be missing?

 

Thanks!

[CallMeDave]

Should I be surprised this isn't happening?

 

No.

 

I ... had assumed that a "member" was effectively the same as a backup set...

 

No, a Member in a Retrospect 8 [color:purple]Media Set[/color] is the same as it was in a Retrospect Classic [color:purple]Backup Set[/color]; the "Set" is the combination of the catalog and the media, same as it ever was.

 

I'm in a situation where I asked for a backup (after a period of time) to "skip to a new member".

 

Remember that if you'd done this in a Retrospect 6 Tape Backup Set you would have needed to supply a new physical tape cartridge; Members are the physical place where the data is stored.

 

I expected that when I asked for "skip to a new member", that Retrospect v8 would create /Backup/Retrospect/SETNAME/2-SETNAME

 

Nope. You need to create (add/supply) new Members for Retrospect to use, just as you'd need to supply a new Tape or a new Removable Disk in this or the previous version.

 

I wanted a new member - in the same backup set.

 

Why? The reason to add a new Member to a Media Set is when the physical storage of the existing member no longer has enough free space to accept new data. The tape is full. Creating multiple Members of a Disk Media Set on the same physical (or logical) hard drive is unnecessary.

 

What I'm trying to do is to be able to move the previous member(s) offline

 

This would be like putting the first tape on the shelf while you continue to writ to the second. It also means that neither the first nor the second tape contain all your data; each is just one Member of the whole Set.

 

If you want to set aside a compete Snapshot (or multiple Snapshots) of your Source(s) for safe keeping you'll need to create a new Media Set, either manually or automatically in a Script's Schedule, just as you would have done in Retrospect Classic

(Backup Sets->YourBackupSet->Configure->Media:Action...->New Media)

[kmpeterson]

Hi Dave,

 

Thanks for taking a swat at this...

 

I'm in a situation where I asked for a backup (after a period of time) to "skip to a new member".

 

Remember that if you'd done this in a Retrospect 6 Tape Backup Set you would have needed to supply a new physical tape cartridge; Members are the physical place where the data is stored.

 

I do remember that. However, using ftp and file backups, this wasn't the case. From the Retrospect User's Guide (v6), "In the case of a new media backup to a file backup set, Retrospect creates a new file in the same folder".

 

I expected that when I asked for "skip to a new member", that Retrospect v8 would create /Backup/Retrospect/SETNAME/2-SETNAME

 

Nope. You need to create (add/supply) new Members for Retrospect to use, just as you'd need to supply a new Tape or a new Removable Disk in this or the previous version.

 

Again, I do understand this - if I were using Tape or removable disk. But I'm not, and what I am confused about is the "Disk Media Set" in v8.

 

I had become very familiar with the ftp backup protocol for v6, where Retrospect would write 16MB files in a way very similar to the 600MB files written to a Disk Media Set. My assumption was because there is a leading "1-" in the file hierarchy written, that a new member would simply be (referencing the files written to the old File media set) a directory with a leading "2-", this being how New Media backups worked in v6.

 

I wanted a new member - in the same backup set.

 

Why? The reason to add a new Member to a Media Set is when the physical storage of the existing member no longer has enough free space to accept new data. The tape is full. Creating multiple Members of a Disk Media Set on the same physical (or logical) hard drive is unnecessary.

 

What I'm trying to do is to be able to move the previous member(s) offline

 

This would be like putting the first tape on the shelf while you continue to writ to the second. It also means that neither the first nor the second tape contain all your data; each is just one Member of the whole Set.

 

You're correct, of course. If we're talking about tapes. But, backup sets using files/disks are different. So different that v8 can recover a file from an in-use Disk Media Set that is also being written to, apparently.

 

If you want to set aside a compete Snapshot (or multiple Snapshots) of your Source(s) for safe keeping you'll need to create a new Media Set, either manually or automatically in a Script's Schedule, just as you would have done in Retrospect Classic

(Backup Sets->YourBackupSet->Configure->Media:Action...->New Media)

 

In Retrospect v6, generating a "New Media" file backup created a new catalog, and a new "set" of files. When using the ftp protocol in v6, this meant a new directory, as well, at the same "level" in the root backup directory, with a serially increasing prefix to the directory name containing the 16MB files. I'd like to be able to do this with a Disk Media Set in v8, except that "Skip to a New Member" doesn't seem to allow adding another member to the same disk. I follow your argument about tapes perfectly, but this is how I used "New Media" backups in v6, and what I'm trying to do now. The backup set written to the Disk Media Set has a "1-" prefix to the directory where the 600MB files are written - why? What's the magic to getting a "2-" prefix directory to appear?

 

I appreciate very much your taking the time to reply to this but it's clear to me what would be the case were I writing tapes - and you're right, here - but my question is about Disk Media Sets.

[CallMeDave]

From the Retrospect User's Guide (v6), "In the case of a new media backup to a file backup set...

 

[color:purple]File Media Sets[/color] in Retrospect 8 behave the same as [color:purple]File Backup Sets[/color] behaved in Classic.

 

what I am confused about is the "Disk Media Set" in v8

 

Fair enough, given the lack of documentation.

 

I'd guess your confusion stems from this:

"backup sets using files/disks are different..."

Yes they are different; [color:red]from each other[/color]. Disk Media Sets are not File Media Sets (which writes a single large file) nor are they Internet Backup Sets (which wrote multiple (undersized) smaller files). Ignore the fact that Retrospect writes multiple files within the member folder, just as you'd ignore the fact that OS X writes multiple file "bands" in a Sparse Bundle disk image.

 

You're correct, of course. If we're talking about tapes...

 

I purposely used the Tape Media Set analogy because it is closer in behavior to the Disk Media Set behavior then what you are used to using.

 

"Skip to a New Member" doesn't seem to allow adding another member to the same disk.

 

Actually it does, if you Add your Member to a subfolder on the Drive. I don't know if it's supported (again due to the lack of documentation) and I've had multiple instances of Retrospect loosing track of Disk Media Set Members (even at the root level of volumes, usually solved by a quick Repair), but on the face of it you can have:

 

/Retrospect/MyFooBackup/1-MyFooBackup/zilllion_AA.rdb

and

/Additional_Retro_Folder/Retrospect/MyFooBackup/2-MyFooBackup/zillion_BB.rdb

 

if that's what you want. But as I noted above, it's not what you want.

 

this is how I used "New Media" backups in v6, and what I'm trying to do now.

 

Yes, Retrospect Classic provided three Media Actions; Normal, Recycle and New Media (which itself was changed from the older trio that had just "New"), but Retrospect 8 has four; [color:purple]No media action[/color] ([color:blue]Normal[/color]), [color:purple]Skip to new member[/color] ([color:blue]a Media Request option, not a Media Action[/color]), [color:purple]Start new media set[/color] ([color:blue]New Media[/color]) and [color:purple]Recycle media set[/color] ([color:blue]Recycle[/color]).

 

The backup set written to the Disk Media Set has a "1-" prefix to the directory where the 600MB files are written - why?

 

Because it's the First Member.

 

What's the magic to getting a "2-" prefix directory to appear?

 

Add an additional Member to the same Media Set in a valid location. Presto.

 

But agin, why do you want a "2-" prefix folder? A New Media backup in Retrospect Classic would name things [0001]MyFooBackup, which although I haven't yet done a Start new media set backup in the current version, I'm gonna assume there will be similar behavior.

 

but my question is about Disk Media Sets.

 

That's never been in doubt. Consider them more as you would consider tapes and things will have an easier time clicking.

 

 

Dave

Edited February 14, 2010 by Guest
Correct the "Skip" option in a Media Request window.

[kmpeterson]

Hi,

 

Okay, thanks for walking through this. I think I am following most of what you've written.

 

It would be really nice if the documentation were more clear about this stuff.

 

Anyway,

 

The backup set written to the Disk Media Set has a "1-" prefix to the directory where the 600MB files are written - why?

 

Because it's the First Member.

 

What's the magic to getting a "2-" prefix directory to appear?

 

Add an additional Member to the same Media Set in a valid location. Presto.

 

And, apparently, a "valid location" can't be on the same "disk" (in this case, share) as the first member - thus, as far as I can tell, making this level of the hierarchy redundant.

 

But agin, why do you want a "2-" prefix folder? A New Media backup in Retrospect Classic would name things [0001]MyFooBackup, which although I haven't yet done a Start new media set backup in the current version, I'm gonna assume there will be similar behavior.

 

It does. Actually, it seems to create a directory at the same level as the original set, with a [001] suffix. I just wish there were a way to do this automatically - the "Start New Media Set" prompts for the location. It does accept the same Disk/share. It doesn't let me automate the process, unfortunately.

 

but my question is about Disk Media Sets.

 

That's never been in doubt. Consider them more as you would consider tapes and things will have an easier time clicking.

 

I appreciate that. Unfortunately, it echoes a complaint I made at some point in the beta process - this stuff is very opaque (not helped by a lack of documentation, either!) and for some of us the ability to easily move stuff around "behind" Retrospect's own management of its backup sets was useful. I see that the description of the 600MB size of the .rdb files cites the ability to "stage the Disk Media set to an Optical Media Set for archival purposes" which is very nice, though a bit more (open) functionality would be appreciated.

 

Again, many thanks for your help. I think I've come to a sufficient understanding of the limitations/features of v8 to do what I need to do now!

 

_KMP

[rhwalker]

It would be really nice if the documentation were more clear about this stuff.

There is no documentation.

 

Russ

[CallMeDave]

apparently, a "valid location" can't be on the same "disk"

 

Up-thread I specifically wrote "[color:purple]Actually it (can), if you Add your Member to a subfolder on the Drive.[/color]" But the point is, if you're storing your files on a single physical or logical volume it doesn't make _any difference_ inside what folder(s) those files reside!

 

the "Start New Media Set" prompts for the location. It does accept the same Disk/share. It doesn't let me automate the process, unfortunately

 

Yeah, this is interesting. A Schedule for a [color:purple]New media backup[/color] does automagically create the Catalog file, but it has to prompt for media the same way it would (and Retrospect Classic would) for a Removable Disk or Tape Media Set; how can the program know where you are storing your backup if you don't tell it?

 

But I do have to join in the wondering how Schedules of this sort are (and were) used? Setting things manually in advance (so there is a properly named Member) would likely work, but then there wouldn't really be the need for the Schedule.

 

Still, best as I can discern, this behavior seems to be the same as was the behavior of the previous version with [color:purple]not_File[/color] and [color:purple]not_Internet[/color] Backup Sets, but since I (as you) primarily used not_Tape I don't have a lot of experience in usability.

 

for some of us the ability to easily move stuff around "behind" Retrospect's own management of its backup sets was useful.

 

If you're going to move things around behind Retrospect's back you have to be sure to re-associate the new location, but you can move Members of a Disk Media Set to different locations/paths and still get things working agin for backup or restore.

 

 

Dave