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There are a lot of articles about SVN vs. Hg in general.
I would like to concentrate only on performance.
Real-live experiences preferred.
Here is my set-up:
(future setup) Windows with IIS fro Hg
(current setup) SVN 1.3.2 on top of apache under windows
I would like to have statistics for most commons operations (commits, stats, local/remote pulls, pushes, etc...). I am not really sure what are the most common operations for Hg.
Performance is NOT the only thing that matters to us but it is highly import and may be the crucial decision point in switching to Hg.
However, I would like to see some statistics. How log did it take to clone repo of 5 gb? or something like that.
First, maybe upgrade your Subversion?
I think the productivity cost of choosing the one that doesn't match the more natural workflow would dwarf any performance differences.
Let's say that Subversion outperforms Mercurial in every way. Great! If the way that you and co-workers use your repository would be better suited to Mercurial, you've become performance-wise and productivity-foolish.
Unless what you're controlling is really huge, you probably won't notice the differences. Choose the one that offers the best capabilities for how you expect to use it.
It depends on so many factors (and no, merging isn't the most common operation - commit is, putting your changes into the thing is the single most important part of it even if DVCS systems do spend all their time merging up and downstream).
So, firstly you need to upgrade your SVN. That's easy, and once you've run 'svnadmin pack' on your repo you'll be able to compare properly. 1.3.2 is ancient! (current version is 1.6.11)
Second, you need to decide whether pushing and pulling large repositories about is important to you. For example, I have a 12 Gig repo to manage. Fortunately, svn allows us to only fetch parts of that, not the whole thing, so management of it is much improved.
Also, there are significant performance improvements coming in v1.7 (ready oh so soon), as performance hasn't been a priority for the SVN guys, they're really been adding features and ensuring rock-solid stability instead. Now, performance is an issue and is being addressed. Take a look on the dev mailing list to see. It might be worth your while to wait a little (or evaluate it using a copy of your repo).
You see, performance may well be the same with your system. It could be bottlenecked on IO which is where svn usually fails (thought the dev mailing list does have some perf figures from a chap with a monster server with raid-0 SSDs, 24 Gb RAM and strangely enough it's bottlenecked on CPU!)
So all in all, you have to figure out your workflow and processes. If Mercurial (which is a good choice) provides that for you, then great, go for it. But if it doesn't, then migrating isn't going to help you no matter how much faster it might be.
(Not exactly an answer, but still it can provide a useful context to your question:)
As mentioned in DVCS tools, the most common operation in a VCS, especially a distributed one, is: merge.
And that, whatever your setup is, will always be easier and quicker to do with Mercurial than SVN. See:
"What makes merging in DVCS easy?"
"SVN merges and DVCS"
"Why is branching and merging easier in Mercurial than in Subversion?"
"What makes some version control systems better at merging?"
"Merging: hg/git vs. svn"
iirc svn is generally quicker for initially getting a remote repo as it doesn't need to pull the history. after that hg is generally quicker as it will use local data much more and has a more compact DB so like for like remote operations are quicker.
at the moment I can only find this as any sort of direct comparison. it is somewhat flawed in that filling any of those VCS with image files is not really what they are for.
if you really want good stats then why not test yourself with your own repo?
Assuming that I'm starting a new web project at home using Visual Studio, which version control system, viz. Git or Subversion will be better to use? Which one will have the least setup complexity?
Since this is for your own personal playing around, my question is simple: Do you know Subversion or Git already?
If you know SVN - use Git.
If you know Git - use SVN.
If you don't know either - use SVN. It's a better introduction.
I'd go with Git. It's not that bad getting up to speed on the basics (there are now a ton of good resources, including learn.github.com) and it'll pay off in spades. And I've been using it on Vista with no probs.
Subversion is far more Windows-friendly in my experience and also more immediately useful for the solo developer.
Another possibility is Perforce, which is slightly less Windows-friendly, but full featured and fairly easy to use, not to mention free for up to two users.
Git is a distributed source control setup and as you are the only user I can't imagine that you would benefit much from its features. Subversion is (in my opinion) easier to set up so I would recommend you go with it.
If you are working alone and want some kind of version control easy to use, then use Subversion.It works great on Windows, setting up the repository is one right click in an empty with Tortoise SVN. Ankh SVN provides a very good integration with Visual Studio - almost on par with TFS provided you use VS 2005 or more recent.
On the other hand, Git is much more promising than SVN. I'll check it during this year, but third party tools are not on par yet.
I'd go with Mercurial instead. It's supposed to be similar to Git (which I never could get running because of the Windows issue) and is really easy to setup in Windows & very nice for "personal" version control systems.
Which one you decide to use depends a lot on what your needs are now and going forward. Git has a very nice community built a round it with GitHub which is great for sharing code and projects. SVN is pretty simple to setup and get going, but in large teams Git has it beat hands down with it's branching and merging. This is ideal in cases where you have multiple people working on the same project, either in an office setting or an OSS sense where the team is spread out.
If all you need is something quick and simple to setup and get going so you can start your project, SVN should be fine. SVN is also integrated into many editors and IDE's as well as many bug tracking and continuous integration systems.
If you plan on having a team, or already do, Git is worth looking at for its branching and merging setup. Git however, due largely to still being kind of young, doesn't have nearly as much support available
If you want Visual Studio integration there is no question. Only Subversion has Visual Studio integrations (AnkhSVN, VisualSVN and several scripts that allow access to TortoiseSVN).
One of the most important reasons that Subversion has such a large amount of tools written for it is that it was designed as a stable library for use by multiple clients.
It's unlikely that Git gets the same level of integration in Visual Studio before git support is available as some kind of reusable library. (There are plans for a libgit2 that could make this a reality).
Let's my ride-in on your question and ask:
Does Git work on Windows?
Does it have something that's equivalent to Tortoise? (otherwise I don't see how it could compete with SVN in terms of ease-of-use)
On a side note: If it's really a one man home project, you don't really need any source control tool. Just put your project in a DropBox folder and you're done (auto-commits, infinite revisions, undelete).
Unless you really think you're going to need tags and branches and stuff. But for personal home projects... do ya?
You can make your own opinion after reading this : http://whygitisbetterthanx.com
Git................................(these dots are there because SO wont accept a 3 lettered answered).
A great answer to this question was recenting written about by Jack Repenning here:
If you have compelling requirements for a single, certain, master copy of your work, use Subversion. You can do this with Git, so long as there are no slip-ups. But you can’t do anything else with Subversion (slip-ups or no), and “compelling requirements” like Sarbanes-Oxley are happier with guarantees than possibilities.
If you plan to maintain parallel, largely shared but permanently somewhat different lines of the same product, use Git. One common example: perhaps you have a large product that you customize for each customer. The customizations are permanent, and generally not shared among code lines, but most of the code is common to all. Git was designed for just this case (in Git terms, local customizations to the common core, and occasional feature or bug-fix contributions back up-tree)
Neither of those? Take your pick, you should be fine with either tool.*
Full Blog Post here: http://blog.codesion.com/post/15692788883/subversion-or-git-decisions-decisions
With SVN you will have to set up a server, create a repository there, check out the (empty) repository, add your files, and then commit.
With Git, all you need is git init in your project's root directory. Then you can add and commit files as you see fit.
There's not really any idea in setting up a Subversion server, since you're the only one working on the source. Contrary to what many people think, solo projects is a perfect match for distributed version control tools. It's also very easy to grow your project later on.
In my experience, Subversion is easier to "grok", but Git is faster and easier to engage in software development best practices. As a former CVS user, Subversion made immediate sense to me when I started using it. Git took some study and I still have to refer to the manual from time to time, but I love how easy it is to branch and merge code when I've got to maintain a release process.
If you are already familiar with CVS and just need something to keep your history and diffs, Subversion will be easier to get started with. If you are new to version control, the tide is shifting toward DVCS in general and Git in particular, so you may get more mileage out of that in general.
I do recommend you look at a hosted provider so you don't have to worry about setting up a Subversion server or so you can have a backup location for your Git data. You can Google for "subversion hosting" or "git hosting" to see the premier providers in the space.
If you plan to take your project along on an USB stick, use Subversion. Windows XP it really, really, really bad at caching lots of small files on an USB stick. Git writes many small files for commit operations and that takes ages on Windows.
[EDIT] The problem with Windows XP and files on an USB stick is caching (or the lack thereof). To prevent data loss, XP will always write files synchonously on an USB stick (so any write will come back only after the FS has reported that all blocks have been written to the stick). Add that to the fact that USB sticks are slow when handling small files (they have a lot of overhead initializing their wear level management) which leads to very poor performance for any kind of application which writes lots of small files.
[EDIT2] If you put a SVN checkout on the USB stick, you will also have a lot of small files (especially in the .svn directories). So the solution in this case is to put the Subversion repository (the "server") on the USB drive. The repository uses only a bunch of big files (if you use the database option instead of the file based one: svnadmin create --fs-type bdb). This avoids the "many little files problem". There is no way to achieve the same thing with current versions of Git.
My project is currently using a svn repository which gains several hundred new revisions per day.
The repository resides on a Win2k3-server and is served through Apache/mod_dav_svn.
I now fear that over time the performance will degrade due to too many revisions.
Is this fear reasonable?
We are already planning to upgrade to 1.5, so having thousands of files in one directory will not be a problem in the long term.
Subversion on stores the delta (differences), between 2 revisions, so this helps saving a LOT of space, specially if you only commit code (text) and no binaries (images and docs).
Does that mean that in order to check out the revision 10 of the file foo.baz, svn will take revision 1 and then apply the deltas 2-10?
What type of repo do you have? FSFS or BDB?
(Let's assume FSFS for now, since that's the default.)
In the case of FSFS, each revision is stored as a diff against the previous. So, you would think that yes, after many revisions, it would be very slow.
However, this isn't the case. FSFS uses what are called "skip deltas" to avoid having to do too many lookups on previous revs.
(So, if you are using an FSFS repo, Brad Wilson's answer is wrong.)
In the case of a BDB repo, the HEAD (latest) revision is full-text, but the earlier revisions are built as a series of diffs against the head. This means the previous revs have to be re-calculated after each commit.
For more info: http://svn.apache.org/repos/asf/subversion/trunk/notes/skip-deltas
P.S. Our repo is about 20GB, with about 35,000 revisions, and we have not noticed any performance degradation.
Subversion stores the most current version as full text, with backward-looking diffs. This means that updates to head are always fast, and what you incrementally pay for is looking farther and farther back in history.
I personally haven't dealt with Subversion repositories with codebases bigger than 80K LOC for the actual project. The biggest repository I've actually had was about 1.2 gigs, but this included all of the libraries and utilities that the project uses.
I don't think the day to day usage will be affected that much, but anything that needs to look through the different revisions might slow down a tad. It may not even be noticeable.
Now, from a sys admin point of view, there are a few things that can help you minimize performance bottlenecks. Since Subversion is mostly a file-based system, you can do this:
Put the actual repositories in a different drive
Make sure that no file locking apps, other than svn, are working on the drive above
Make the drives at least 7,500 RPM. You could try getting 10,000 RPM, but it may be overkill
Update the LAN to gigabit, if everybody is in the same office.
This may be overkill for your situation, but that's what I've usually done for other file-intensive applications.
If you ever "outgrow" Subversion, then Perforce will be your next step up. It's hands down the fastest source control app for very large projects.
We're running a subversion server with gigabytes worth of code and binaries, and it's up to over twenty thousand revisions. No slowdowns yet.
Subversion only stores the delta (differences), between 2 revisions, so this helps saving a LOT of space, specially if you only commit code (text) and no binaries (images and docs).
Additionally I´ve seen a lot of very big projects using svn and never complained about performance.
Maybe you are worried about checkout times? then I guess this would really be a networking problem.
Oh, and I´ve worked on CVS repositories with 2Gb+ of stuff (code, imgs, docs) and never had an performance problem. Since svn is a great improvement on cvs I don´t think you should worry about.
Hope it helps easy your mind a little ;)
I do not think that our subversion slowed down by aging. We have currently several TeraBytes of data, mostly binary. We checkout/commit daily up to 50 GigaByte of data. In total we have currently 50000 revisions. We are using FSFS as storage type and are interfacing either directly SVN: (Windows server) or via Apache mod_dav_svn (Gentoo Linux Server).
I cannot confirm that this gets svn to slowdown over time, as we set up a clean server for performance comparison which we could compare to. We could NOT measure a significant degration.
However I have to say that our subversion is uncommonly slow by default and obviously it is subversion itself as we tried with another computer system.
For some unknown reasons subversion seems to be completly server CPU limited. Our checkout/commit rates are limited to in between 15-30 MegaBytes/s per client because then one server CPU core is completly used up. This is the same for an almost empty repository (1 GigaByte, 5 revisions) as for our full server (~5 TeraByte, 50000 revisions). Tuning like setting compression to 0 = off did not improve this.
Our High Bandwith (delivers ~1 GigaByte/s) FC-Array idles, the other cores idle and network (currently 1 GigaBit/s for clients, 10 GigaBits/s for server) idles as well. Okay not really idling but if only 2-3% of available capacity is used I call it idling.
It is no real fun to see all components idling and we need to wait for our working copies to get checked out or comitted. Basically I have no idea what the server process is doing by fully consuming one CPU core all the time during checkout/commit.
However I am just trying to find a way to tune subversion. If this is not possible we might need to switch to another system.
Therefore: Answer: No SVN does not degrade in performance it is initially slow.
Of course if you do not need (high) performance you won't have a problem.
Btw. all the above applies to subversioon 1.7 latest stable version
The only operations which are likely to slow down are things which read information from multiple revisions (e.g. SVN Blame).
I am not sure..... I am using SVN with apache on Centos 5.2. Works ok. Revision number was 8230 something like that... And on all client machines Commit was so slow that we had to wait at least 2min for a file that is 1kb. I am talking about 1 file that has no big filesize.
Then I made a new repository. Started from rev. 1. Now works ok. Fast.
used svnadmin create xxxxxx.
did not check if it is FSFS or BDB.....
Maybe you should consider improving your workflow.
I don't know if a repos will have perf issues in these conditions, but you ability to go back to a sane revision will.
In your case, you may want to include a validation process, so a team commit in a team leader repo, and each of them commit to the team manager repo who commit to the read-only clean company repos. You have make a clean selection at it stage of what commit must go to the top.
This way, anybody can go back to a clean copy, with an easy to browse history. Merge are much easier, and dev can still commit their mess as much as they want.
I am currently working in a project with developers working on three sites. One of the sites is in Delhi, India while the other two are in Europe. The communication between the European offices and the office in Delhi has poor bandwidth and quite bad latency, and a CVS update from there often takes 5-10 minutes even though only a few files have changed.
Is there any good CVS proxies out there, or any neat way of keeping separate CVS servers in sync? Do you have any other tips on how the performance can be improved in this scenario?
Unfortunately, we will be stuck with CVS during the scope of this project, so switching to something completely different is not an option in the short-term.
Why isn't switching an option?
I would highly recommend to switch to SVN or git instead. And that you do this conversion as soon as possible... like today :)
There are even svn tools/guides and git tools/guides out there that will do this CVS conversion for you.
I personally use and love SVN for my work, but based on your above description, it sounds like git might be the better option for you.
Here is what I have done a long time ago in similar circumstances when bandwidth and unreliable networks were an issue:
Make a copy of the repository and install it in the remote location. You know have CVS1 and CVS2.
Lock one of the two copies (CVS1) by preventing commits. This is achieved by modifying 'commitinfo' in the CVSROOT module.
CVS1 can be used for updates only
CVS2 can be used for updates and commit
When you want to give access in commit to copy 1, proceed as follows:
Lock CVS2
Copy CVS2 to CVS1
Unlock CVS1
This sounds cumbersome, and it is if you do it manually, but it works. It requires a bit of discipline if you do it manually. May be timezones are on your side for once.
I wrote a tool to keep track of who had the commit token and to transfer repositories from one site to another automatically via rsync and SSH. It worked nicely for a couple of years. We never lost any data and it took about 5 minutes to transfer the token from one location to another.
The transfer tool was written in perl and it took me about two weeks to develop it, working on it full time.
I know that a long time ago FreeBSD developers used CVSup but I never used that tool myself.
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My development team uses source safe at a very basic level. We're moving into some more advanced and extended development cycles and I can't help but think that not using branching and merging in order to manage changes is going to be biting us very soon.
What arguments did you find most useful in order to convince your team to move to a better solution like SVN?
What programs did you use to bridge the functionality gap so that the team wouldn't miss the ide sourcesafe integration?
Or should I just accept sourcesafe and attempt to shoehorn better practices into it?
Reliability
SVN is a lot more reliable with large databases
SVN is still actively supported
Atomic commit - in VSS when you get latest version while another user is performing checkin, you can get an inconsistent state, forcing you to repeat the "Get latest version" in better case, but sometimes when unlucky you may be left with a codebase which compiles but does not work. This cannot happen in SVN thanks to atomic commits.
Features
SVN branch/merge is a lot better
SVN has builtin support for remote access
SVN is more configurable (integration of external Diff/Merge tools)
SVN is more extensible (hooks)
Better productivity
SVN "Update" is a lot faster compared to SS "Get latest version"
SVN command line is a lot easier and cleaner - this is useful for automated build or testing tools
Same level of IDE Integration
VSS had a lot better VS integration until recently, but with AnkhSVN 2.0 this is no longer true.
Open
SVN is open and there is plenty of various tools using SVN or cooperating with it. Some examples include:
integration with many bug tracker or product cycle management products
shell integration
integration into various products
various management and analysis tools
source is available, you can adjust it to your need, fix the problems (or hire someone to do it for you) should the need arise
Cost
You do not have to pay any license or maintenance fees
First, teach them how to use SourceSafe in an efficient way.
If they are smart enough, they will begin to love the advantages of using a version-control system, and if so, they will soon reach the limits of SourceSafe. That's where they will be the more able to listen to your arguments for switching to a better VCS, could it be a CVCS or a DVCS, depending on what's the team is ready to achieve.
If you try to force them to use another VCS when they use SourceSafe in a wrong way, like saving zip file of source code (don't laugh, that's how they were acting in my company two years ago), they will be completly reluctant to any argumentation, as good as it could be.
Find some excuse to start using non-ASCII characters in your C# code (Chinese and Japanese are excellent for this).
SourceSafe doesn't like Unicode (even though Visual Studio does), so if you choose the right Unicode text and check a file in and back out, your entire file will appear as corrupted gibberish. The beauty of this is that because SS uses a "diff" versioning system, this actually corrupts the file all the way back to the original check-in version, and can't be fixed automatically.
When this happens just one time (as it did to me when working on an application that had to support Japanese), you will probably find it to be a decisive argument in favor of dropping SourceSafe.
There were two features that we used to sell management and the team on SVN over VSS.
1) The ability to branch. When using VSS, when a release was scheduled to go out, the entire repository was locked until the release actually went out. This included the test and fix cycle. So, developers were unable to commit anything other than fixes for the release to the VSS repository. This resulted in long integration sessions immediately following each release. With the use of release branches in SVN, there is no longer any need to lock the entire repository.
2) The ability to rollback an entire change at once. Because SVN records all files changed in a single, atomic commit, it is trivial to revert a problematic change. In VSS, a developer had to go through the entire repository and find every file changed at about the same time and revert each change to each file individually. With SVN, this is as trivial as finding the relevant commit and hitting the "Revert Changes from this Commit" button in TortoiseSVN.
As a side note, we use TortoiseSVN and everyone loves the file overlay icons for seeing what has and has not changed.
Whatever you do, move slowly! Don't start talking to them about branching on Day 1 -- it will just put them off. I'm stereotyping VSS users with that comment, but that's what I see out there.
For the developers: sell it as a replacement for VSS that works better and faster. Use VisualSVN on Day 1 so they have a super-shallow learning curve. Sell them on it being the same except faster, more stable, and 2 people can edit the same file and they won't have problems with some guy being off sick with locks on a bunch of files.
For the admins: sell them on it being more stable and easier to administer than VSS. Show them VisualSVN server.
Good luck!
First, document all the problems you are having that can be traced to root causes within the source control system. Keep track of them for a month or so. Add on top of that missed opportunities resulting from not using it. (if you say "opportunity costs of not using subversion" you may impress an MBA-type manager). These numbers are actually an understimate of the opportunity cost because presumably you could have been doing work that provides more than your hourly bill rate of value if you weren't messing around with VSS.
For example, do you have problems where files are locked that need to be accessed by more than one person?
Have you had problems with partial (non-atomic) check-ins?
Do you have problems where it is difficult for you to keep track of releases of the software and recreate the repository as it was in the past?
Do you have problems getting a copy of the code onto a server that doesn't have a sourcesafe client?
Do you have problems automating your build and testing process because continuous integration tools can't monitor your version control systems for updates?
I am sure you can think of many others.
If you can figure out the approximate time/money costs of problems caused by sourcesafe and benefits of things that subversion provides (using a generic number like $100/hr for labor costs or just hours) and any costs of late delivery of projects, do so. If you have collected data for a month or so, you can show the benefit using subversion per month.
Then present the approximate time/cost of moving to subversion. (About 8 hours to setup and migrate code, and 2 hours per developer to connect, checkout and move projects, something like that) The risk is low, since sourcesafe is still there to rollback to.
If the cost is more than the monthly benefit, you can divide the cost by the benefit to figure out the recovery period. You should also total it up over 3 years or so to show the long term benefit. Again, emphasize that the real opportunity cost is not directly calculable because you could have been adding value during the time you were trying to manage non-branched releases in sourcesafe.
Nobody recommends using SourceSafe any more, not even Microsoft. They will now offer you an (expensive) TFS licence instead. SourceSafe is just not reliable.
I wrote about it here: Visual SourceSafe on E2. It's a bit of a rant, but that's because I had to use SourceSafe for quite a while, and the memory makes me froth at the mouth a bit.
Reliablity is the big one that will bite you. But also there are features that you may appreciate in SVN or TFS:
TFS and SVN both have atomic commits of multiple files, but Sourcesafe does not - if you check in two files "at once", it's not one operation, it's the same as checking in one of the files, then checking in the other. You can get at the state in between, where one file has been checked in, but not the other.
SourceSafe does not keep history of deleted files, file moves or renames.
Contrary to initial impressions, SourceSafe does support multiple simultaneous checkouts of the same file, if you set the right options. But TFS and especially SVN are better designed for this way of working
Unlike SourceSafe, TFS and SVN both work fine against servers on the internet (TFS just OK, SVN excellently) and SVN works well offline - e.g. if you have a laptop on a plane or train and no 'net, you can still work and compare to previous revisions or even revert, since the data to do that is held locally.
As someone else pointed out, SourceSafe, like CVS, is a "dead" product. It is not being actively developed. TFS and SVN will have next versions out some time in the future.
First search google for the sheer quantity of pages describing how bad VSS is and share that with your coworkers.
Second, skip subversion and go straight to a proper distributed SCM like git or mercurial. Because merging is such an inherent part of distributed SCMs, they have to handle merges much better than centralized systems like svn. Subversion is still trying to retrofit itself to handle branching better, where the distributed systems were built correctly to begin with.
The AnkhSVN plugin for VS is pretty good. It's got a few oddities but on the whole works well.
Convincing the team to move is hard work - I never managed it :-( Probably one of the more practical arguments though is speed - VSS is s-l-o-w when you've got a 1GB source database and several users.
edit It's been so long since I used VSS I forgot it was locking! Yes, as mentioned here the ability to move to a non-exclusive/merge changes model should help if you've got more than a handful of developers. It saves yelling "Can somebody check in the common includes" across the office!
You say "What arguments did you find most useful in order to convince your team to move to a better solution like SVN?"
If you don't know that it's a better solution, then why are you making the arguments? If your mind is made up enough to go argue for a solution, you should know what those reasons are already.
What convinced you that you should move to something better? Those are your arguments right there. Anything short of those arguments will sound like it's just an issue of personal preference.
TortoiseSvn (free) is really nice for explorer integration, giving you all the features of svn from a context menu.
VisualSvn (commercial) makes it just as easy to integrate svn into Visual Studio, with the same status indication in the solution browser as well as context menus to use all the subversion features.
Both these tools go a long way to making version control seamless. It's been a coupe of years since I dealt with VSS, but these tools are a way nicer way to use source control.
Ditto for what every one has said about VSS being poop
Subversion has good support for branching and doing merges... I don't remember VSS having any capabilities in this department at all. I do remember teams going through pain of week long merges when needing to release from VSS, pain which just doesn't exist anymore with Subversion.
Build some automation that mirrors the VSS repository into a SVN repository
It takes time to build a consensus. If your SVN mirror of the VSS repository is available at all times, it will be easier to accumulate converts. The mirror doesn't have to be perfect- it just has to be usable. There are existing tools for this purpose.
Tell them to treat the source code as if it was money and point them to the numerous examples of SourceSafe coming down in flames taking the source with it. Things like that are just not supposed to happen in a proper source control system.
The best argument against SourceSafe is that it is just isn't Safe, everything else can potentially be called "features we don't need".
The clincher for us was the speed (i.e., the lack thereof) of VSS over VPN and low bandwidth hotel networks on the road and the problems of trying to tunnel through firewalls so that two teams at two different sites could quickly, securely, and reliably work from the same code repository. We were running two VSS repositories and packaging up "deliveries" that had to be merged into the other site's repository to keep them in sync.
The team grumbled for a while, but quickly got over it. TortoiseSVN is fantastic by itself and the AnkhSVN plug-in for Visual Studio really eased everyone into the changeover.
Looking back, I can't believe how many "Can you check in file SoAndSo?" e-mails we sent around, not to mention the "SourceSafe is down. We've got to restore the repository" e-mails.
Sheesh. After reading this comments and writing this response, I can't believe we put up with VSS for as long as we did.
Web page summarising problems with VSS - just point people to that URL
If you use VisualSVN the team won't miss VSS as much. 2 people being able to work on one file at the same time is a big selling point too.
The unreliability of source safe ("please fix the repository...") was enough of a sell for us. Andecdotally (I've never measured it) SVN also always seems faster. Good concurrent checkouts / merging.
I'd always figured that to a developer it was almost too obvious. SourceSafe just seems to break and die all too often to not want to replace it...
Tell them to read this http://www.highprogrammer.com/alan/windev/sourcesafe.html
I would recommend that you go ahead and start introducing best practices to your sourcesafe usage with a view to changing to subversion further down the line. Hopefully this will make your actual subversion migration easier and give you time to sort plan out your development cycles, branching strategies et al. properly.
The other thing to consider is your development process in general. A source control management system is only ever part of the solution, to get the most out of subversion or any other product you will probably want to look at how it's usage interacts with your code review, qa and build processes.
I don't remember any SourceSafe user ever liking the product. Do your colleagues actually like it?
I've got a similar issue with CVS at my current customer's usage. Since "it works" and they are mostly pleased with it, I cannot push them to change. But daily I sure wish they would!
When I was at the launch for VS2005 I managed to corner a Microsofty and ask why SourceSafe was so awful to use. The reply I got was rather shocking, not just because of what he said but because he was so up front about what he'd said.
He told me that it was only really meant for one person to use and even then it wasn't very good at doing that.
My colleagues and I were a bit shocked we couldn't think of much else to do other than laugh out loud, as did the Microsofty! He then told us that it wasn't used internally.
So, we switched to subversion shortly after that. We'd pretty much decided to go for it before the launch event, but that just confirmed we'd made the right decision.
We used to use SourceSafe. Then, when I joined the team I was in a different location and even though we have a fairly good LAN when I tried to check out the latest version it took 40 minutes. I persuaded them to convert to CVS (we now use SVN) and the checkout time dropped to a couple of minutes. SourceSafe was just too slow to be usable at a remote location.
We moved from SourceSafe to Source Gear Vault. This source control engine is very comfortable for some one used to SourceSafe. We finally decided to make the change after a couple SourceSafe corruption incidents, that came at critical times. So my advice would be to focus your sales presentation on SourceSafes unreliability.
Surely using source safe is enough reason to want to migrate to another source control system?
I used SVN and CVS at my old job and have moved to a company that uses Source safe (we are going to migrate to SVN) and just using VSS has been enough for me to take a serious dislike to it. I went in with an open mind, despite many of my colleagues from my previous job telling me horror stories about VSS I assumed that it would have gotten better since they used it.
Not being able to edit a file because somone else is/was editing it is ridiculous. I've tried to move to more distributed versioning systems like Bazzar which is made by cannonical however it's not mature enough in terms of the tools available.
Source safe gets in the way of development where SVN helps you almost every step of the way.
Plus Using tortoise Svn made code reviews a lot easier.
Only to the extend as you are able to herd a bunch of cats. I've been there twice and in both cases it took some serious problems in Source Safe before people saw the light. As a manager on the other hand I simply directed the team to use SVN and our productivity increased by 300% ( this was working with a group in India and in the US. We had code exchanges that used to take a long time before svn )
Also Trac mounts on top of Subversion. It's free and a great way to view the repository (timeline, wiki, etc)
As you're making these arguments, consider whether you need to address any policy your company may have about using open source tools. See this answer to a prior question: Switching source control
Make them use it and they will switch to something else :)
Now, being serious, tell them its not that hard to use it, many developers that I've known refused to switch because they related subversion to unix and wierd commands, show them interfaces like ToirtoiseSVN or VisualSVN, tell them that Subversion allows them to edit the same file withouth a forced locking like VSS does.
And last but not least, it is Open Source. It has lower cost than buying Team Foundation Server and if you look around you will see that small teams of developers work quite well with SVN.
I used SourceSafe on a small development team and was responsible for keeping it running.
I found the database gets corrupted pretty easily, and there isn't much recourse when that happens. The "repair" feature (as with most any Microsoft repair feature) just doesn't work 98% of the time.
Naturally, when our database became corrupt, we tried to restore from our backup archive. That was when we discovered the other bad thing about SourceSafe: its 2GB archive limit. We were making backups at our office for months before we ever realized that they couldn't be restored and were useless.
SourceSafe is just a disaster waiting to happen.
I'm planning on ditching SourceSafe in the next few weeks, after over a decade of putting up with it. Mostly I've been using it within the context of a small (< 5 person) team, and not had to do a lot of branching because there's been no call to do it.
However, the #1 problem for me, and always has been, is that the damn thing is so prone to corruption - if you have your SS database (lol, database; collection of randomly named files more accurately describes it) on a network drive, and something happens to your LAN connection partway through an add/checkin operation - 9 times out of ten you get "invalid handle" and the damn thing is corrupted in some way, and then you get to play Russian Roulette with the Analyzer tool.
I realised, a couple of months back, that for the past decade I had been making local zipped up copies of the source at every release of the software I was working on, because I didn't trust the source control system. What a waste of time.
So, it's going. I'll probably use Subversion and TortoiseSVN, because I think the team will need a UI to ease the transition.