EEK. I'm sure this is not the answer, because if I rename the
filesystem everyday, then I have to do a full backup of the filesystem
every day. I don't think there are enough hours in the day to do a full
backup, export it, and delete the filespace. Thanks for the suggestion
though.
Ben Bullock
UNIX Systems Manager
(208) 368-4287
> -----Original Message-----
> From: Lambelet,Rene,VEVEY,FC-SIL/INF.
> [mailto:Rene.Lambelet AT NESTLE DOT COM]
> Sent: Monday, February 26, 2001 1:13 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Performance Large Files vs. Small Files
>
>
> Hello,
>
>
> you might think of renaming the node every day, then doing an export
> followed by a delete of the filespace (this will free the DB).
>
> In case of restore, import the needed node
>
> René Lambelet
> Nestec S.A. / Informatique du Centre
> 55, av. Nestlé CH-1800 Vevey (Switzerland)
> *+41'21'924'35'43 7+41'21'924'28'88 * K4-117
> email rene.lambelet AT nestle DOT com
> Visit our site: http://www.nestle.com
>
> This message is intended only for the use of the
> addressee and
> may contain information that is privileged and confidential.
>
>
> > -----Original Message-----
> > From: bbullock [SMTP:bbullock AT MICRON DOT COM]
> > Sent: Tuesday, February 20, 2001 11:22 PM
> > To: ADSM-L AT VM.MARIST DOT EDU
> > Subject: Re: Performance Large Files vs. Small Files
> >
> > Jeff,
> > You hit the nail on the head of what is the biggest
> problem I face
> > with TSM today. Excuse me for being long winded, but let me
> explain the
> > boat
> > I'm in, and how it relates to many small files.
> >
> > We have been using TSM for about 5 years at our
> company and have
> > finally got everyone on our band wagon and away from the variety of
> > backup
> > solutions and media we had in the past. We now have 8 TSM
> servers running
> > on
> > AIX hosts (S80s) attached to 4 libraries with a total of 44
> 3590E tape
> > drives. A nice beefy environment.
> >
> > The problem that keeps me awake at night now is
> that we now have
> > manufacturing machines wanting to use TSM for their
> backups. In the past
> > they have used small DLT libraries locally attached to the host, but
> > that's
> > labor intensive and they want to take advantage of our
> "enterprise backup
> > solution". A great coup for my job security and TSM, as
> they now see the
> > benefit of TSM.
> >
> > The problem with these hosts is that they generate
> many, many
> > small
> > files every day. Without going into any detail, each file
> is a test on a
> > part that they may need to look at if the part ever fails.
> Each part gets
> > many tests done to it through the manufacturing process, so
> many files are
> > generated for each part.
> >
> > How many files? Well, I have one Solaris-based host
> that generates
> > 500,000 new files a day in a deeply nested directory
> structure (about 10
> > levels deep with only about 5 files per directory). Before
> I am asked,
> > "no,
> > they are not able to change the directory of file structure
> on the host.
> > It
> > runs proprietary applications that can't be altered". They
> are currently
> > keeping these files on the host for about 30 days and then
> deleting them.
> >
> > I have no problem moving the files to TSM on a
> nightly basis, we
> > have a nice big network pipe and the files are small. The
> problem is with
> > the TSM database growth, and the number of files per
> filesystem (stored in
> > TSM). Unfortunately, the directories are not shown when you
> do a 'q occ'
> > on
> > a node, so there is actually a "hidden" number of database
> entries that
> > are
> > taking up space in my TSM database that are not readily
> apparent when
> > looking at the output of "q node".
> >
> > One of my TSM databases is growing by about 1.5 GB
> a week, with no
> > end in sight. We currently are keeping those files for 180
> days, but they
> > are now requesting that them be kept for 5 years (in case a
> part gets
> > returned by a customer).
> >
> > This one nightmare host now has over 20 million
> files (and an
> > unknown number of directories) across 10 filesystems. We
> have found from
> > experience, that any more than about 500,000 files in any
> filesystem means
> > a
> > full filesystem restore would take many hours. Just to restore the
> > directory
> > structure seems to take a few hours at least. I have told
> the admins of
> > this
> > host that it is very much unrecoverable in it's current
> state, and would
> > take on the order of days to restore the whole box.
> >
> > They are disappointed that an "enterprise backup
> solution" can't
> > handle this number of files any better. They are willing to
> work with us
> > to
> > get a solution that will both cover the daily "disaster
> recovery" backup
> > need for the host and the long term retentions they desire.
> >
> > I am pushing back and telling them that their
> desire to keep it
> > all
> > for 5 years is unreasonable, but thought I'd bounce it off
> you folks to
> > see
> > if there was some TSM solution that I was overlooking.
> >
> > There are 2 ways to control database growth: reduce
> the number of
> > database entries, or reduce the retention time.
> >
> > Here is what I've looked into so far.
> >
> > 1. Cut the incremental backup retention down to 30 days and
> then generate
> > a
> > backup set every 30 days for long term retention.
> > On paper it looks good. you don't have to move the
> data over the
> > net
> > again and there is only 1 database entry. Well, I'm not
> sure how many of
> > you
> > have tried this on a filesystem with many files, but I
> tried it twice on a
> > filesystem with only 20,000 files and it took over 1 hour
> to complete.
> > Doing
> > the math it would take over 100 hours to do each of these 2
> million-file
> > filesystems. Doesn't seem really feasible.
> >
> > 2. Cut the incremental backup retention down to 30 days and run and
> > archive
> > every 30 days to the 5 year management class.
> > This would cut down the number of files we are
> tracking with the
> > incrementals, so a full filesystem restore from the latest
> backup would
> > have
> > less garbage to sort through and hopefully run quicker. Yet with the
> > archives, we would have to move the 600 GB over the net
> every 30 days and
> > would still end up tracking the millions of individual
> files for the next
> > 5
> > years.
> >
> > 3. Use TSM as a disaster recovery solution with a short 30
> day retention,
> > and use some other solution (like a local CD/DVD burner) to
> get the 5 year
> > retention they desire. Still looking into this one, but
> they don't like it
> > because it once again becomes a manual process to swap out CDs.
> >
> > 4. Use TSM as a disaster recovery solution (with a short 30
> day retention)
> > and have a process tar up all the 30-day old files into one
> large file,
> > then
> > have TSM do an archive and delete .tar file. This would
> mean we only track
> > 1
> > large tar file for every day for the 5 year time (about
> 1800 files). This
> > is
> > the option we are currently pursuing.
> >
> > Any other options or suggestions from the group?
> Any other backup
> > solutions you have in place for tracking many files over
> longer periods of
> > time?
> >
> > If you made it this far through this long e-mail, thanks for
> > letting
> > me drone on.
> >
> > Thanks,
> > Ben Bullock
> > UNIX Systems Manager
> > Micron Technology
> >
> >
> > > -----Original Message-----
> > > From: Jeff Connor [mailto:connorj AT NIAGARAMOHAWK DOT COM]
> > > Sent: Thursday, February 15, 2001 12:01 PM
> > > To: ADSM-L AT VM.MARIST DOT EDU
> > > Subject: Re: Performance Large Files vs. Small Files
> > >
> > >
> > > Diana,
> > >
> > > Sorry to chime in late on this but you've hit a subject I've been
> > > struggling with for quite some time.
> > >
> > > We have some pretty large Windows NT file and print servers
> > > using MSCS.
> > > Each server has lots of small files(1.5 to 2.5 million)
> and total disk
> > > space(the D: drive) between 150GB and 200GB, Compaq server,
> > > two 400mhz xeon
> > > with 400MB ram. We have been running TSM on the
> mainframe since ADSM
> > > version 1 and are currently at 3.7 of the TSM server with
> 3.7.2.01 and
> > > 4.1.2 on the NT clients.
> > >
> > > Our Windows NT admins have had a concern for quite some time
> > > regarding TSM
> > > restore performance and how long it would take to restore
> > > that big old D:
> > > drive. They don't see the value in TSM as a whole as
> compared to the
> > > competition they just want to know how fast can you recover
> > > my entire D:
> > > drive. They decided they wanted to perform weekly full
> > > backups to direct
> > > attached DLT drives using Arcserve and would use the TSM
> > > incrementals to
> > > forward recover during full volume restore. We had to
> > > finally recover one
> > > of those big D: drives this past September. The Arcserve
> > > portion of the
> > > recovery took about 10 hours if I recall correctly. The
> TSM forward
> > > recovery ran for 36 hours and only restored about 8.5GB.
> > > They were not
> > > pleased. It seems all that comparing took quite some time.
> > > I've been
> > > trying to get to the root of the bottleneck since then. I've
> > > worked with
> > > support on and off over the last few months performing
> > > various traces and
> > > the like. At this point we are looking in the area of
> > > mainframe TCPIP and
> > > delay's in acknowledgments coming out of the mainframe during test
> > > restores.
> > >
> > > If you've worked with TSM for a number of years and
> through sources in
> > > IBM/Tivoli and the valuable information from this listserv,
> > > over time you
> > > learn about all the TSM client and server "knobs" to turn to
> > > try and get
> > > maximum performance. Things like Bufpoolsize, database
> cache hits,
> > > housekeeping processes running at the same time as
> > > backups/restores slowing
> > > things down, network issues like auto-negotiate on NIC's, MTU
> > > sizes, TSM
> > > server database and log disk placement, tape drive
> load/seek times and
> > > speeds and feeds. Basically, I think we are pretty well set
> > > with all those
> > > important things to consider. This problem we are having may be a
> > > mainframe TCPIP issue in the end, but I am not sure that
> will be the
> > > complete picture.
> > >
> > > We have recently installed an AIX TSM server, H80 two-way,
> > > 2GB memory,
> > > 380GB EMC 3430 disk, 6 Fibre Channel 3590-E1A drives in a
> > > 3494, TSM server
> > > at 4.1.2. We plan to move most of the larger clients from
> > > the TSM OS/390
> > > server to the AIX TSM server. A good move to realize a
> performance
> > > improvement according to many posts on this Listserv over the
> > > years. I am
> > > in the process of testing my NT "problem children" as quickly
> > > as I can to
> > > prove this configuration will address the concerns our NT
> > > Admins have about
> > > restores of large NT servers. I'm trying to prevent them
> > > from installing a
> > > Veritas SAN solution and asking them to stick with our
> > > Enterprise Backup
> > > Strategic direction which is to utilize TSM. As you probably
> > > know, the SAN
> > > enabled TSM backup/archive client for NT is not here and may
> > > never be from
> > > what I've heard. My only option at this point is SAN tape
> > > library sharing
> > > with the TSM client and server on the same machine for each
> > > of our MSCS
> > > servers.
> > >
> > > Now I'm sure many of you reading this may be thinking of
> > > things like, "why
> > > not break the D: drive into smaller partitions so you can
> collocate by
> > > filespace and restore all the data concurrently". No go
> > > guys, they don't
> > > want to change the way they configure their servers just to
> > > accommodate TSM
> > > when the feel they would not have to with other products.
> > > They feel that
> > > with 144GB single drives around the corner who is to say what
> > > a "big" NT
> > > partition is? NT seems to support these large drives
> without issues.
> > > (Their words not mine).
> > >
> > > Back to the issue. Our initial backup tests using our new
> > > AIX TSM server
> > > have produced significant improvements in performance. I am
> > > just getting
> > > the pieces in place to perform restore tests. My first test
> > > a couple days
> > > ago was to restore part of the data from that server we had
> > > the issue with
> > > in September. It took about one hour to lay down just
> the directories
> > > before restoring any files. Probably still better than the
> > > mainframe but
> > > not great. My plan for future tests is to perform backups
> > > and restores of
> > > the same data to and from both of my TSM servers to compare
> > > performance. I
> > > will share the results with you and the rest of the listserv
> > > as I progress.
> > >
> > > In general I have always, like many other TSM users, achieved
> > > much better
> > > restore/backup rates with larger files versus lots of
> smaller files.
> > > Assuming you've done all the right tuning, the question that
> > > comes to my
> > > mind is, does it really come down to the architecture? The
> > > TSM database
> > > makes things very easy for day to day smaller recoveries
> > > which is the type
> > > we perform most. But does the architecture that makes day to day
> > > operations easier not lend itself well to backup/recovery of
> > > large amounts
> > > of data made up of small files? I have very little
> experience with
> > > competing products. Do they struggle with lots of small
> files as well?
> > > Veritas, Arserve anyone? If the issue is, as some on the
> > > Listserv have
> > > suggested, frequent interaction with the client file system
> > > the bottleneck,
> > > then I suppose the answer would be yes the other products
> > > have the same
> > > problem. Or is the issue more on the TSM database side due
> > > to it's design,
> > > and other products using different architectures may not have
> > > this problem?
> > > Maybe the competitions architecture is less bulletproof but
> > > if you're one
> > > of our NT Admins you don't seem to care when the client
> keeps calling
> > > asking how much longer the restore will be running. I know TSM
> > > development is aware of the issues with lots of small files
> > > and I would be
> > > curious what they plan to do about the problems Diana and I have
> > > experienced.
> > >
> > > The newer client option, Resourceutilization, has helped with
> > > backing up
> > > clients with lots of small files more quickly. I would love
> > > to see the
> > > same type of automated multi-tasking on restores. I
> don't know the
> > > specifics of how this actually works but it seems to me that
> > > when I ask to
> > > restore an entire NT drive, for example, the TSM
> > > client/server must sort
> > > the file list in some fashion to intelligently request
> tape volumes to
> > > minimize the mounts required. If that's the case could they
> > > take things
> > > one step further and add an option to the restore specifying
> > > the number of
> > > concurrent sessions/mountpoints to be used to perform the
> > > restore? For
> > > example, if I have a node who's collocated data is spread
> > > across twenty
> > > tapes and I have 6 tape drives available for the recovery,
> > > how about an
> > > option for the restore command like:
> > >
> > > RES -subd=y -nummp=6 d:\*
> > >
> > > where the -nummp option would be the number of mount
> > > points/tape drives to
> > > be used for the restore. TSM could sort the file list coming
> > > up with the
> > > list of tapes to be used for the restore and perhaps
> spread the mounts
> > > across 6 sessions/mount points. I'm sure I've probably made
> > > a complex task
> > > sound simple but this type of option would be very useful. I
> > > think many of
> > > us have seen the benefits of running multiple sessions to
> > > reduce recovery
> > > elapsed time. I find my current choices for doing so difficult to
> > > implement or politically undesirable.
> > >
> > > If others have the same issues with lots of small files in
> > > particular with
> > > Windows NT clients lets hear from you. Maybe we can come
> up with some
> > > enhancement requests. I'll pass on the results of my
> tests as stated
> > > above. I'd be interested in hearing from those of you that
> > > have worked
> > > with other products and can tell me if they have the same
> performance
> > > problems with lots of small files. If the performance of
> > > other products is
> > > impacted in the same was as TSM performance then that
> would be good to
> > > know. If it's more about the Windows NT NTFS file system
> then I'd be
> > > satisfied with that explanation as well. If it's about lots
> > > of interaction
> > > with the TSM database leads to slower performance, even
> when optimally
> > > configured, then I'd like to know what Tivoli has in the
> > > works to address
> > > the issue. Because if it's the TSM database, I could
> > > probably install the
> > > fattest Fibre Channel/network pipe with the fastest
> > > peripherals and server
> > > hardware around and it might not change a thing.
> > >
> > > Thanks
> > > Jeff Connor
> > > Niagara Mohawk Power Corp.
> > >
> > >
> > >
> > >
> > >
> > >
> > > "Diana J.Cline" <Diana.Cline AT ROSSNUTRITION DOT COM>@VM.MARIST.EDU> on
> > > 02/14/2001 10:04:52 AM
> > >
> > > Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
> > >
> > > Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
> > >
> > >
> > > To: ADSM-L AT VM.MARIST DOT EDU
> > > cc:
> > >
> > > Subject: Performance Large Files vs. Small Files
> > >
> > >
> > > Using an NT Client and an AIX Server
> > >
> > > Does anyone have a TECHNICAL reason why I can backup 30GB of
> > > 2GB files that
> > > are
> > > stored in one directory so much faster than 30GB of 2kb
> files that are
> > > stored
> > > in a bunch of directories?
> > >
> > > I know that this is the case, I just would like to find out
> > > why. If the
> > > amount
> > > of data is the same and the Network Data Transfer Rate is the
> > > same between
> > > the
> > > two backups, why does it take the TSM server so much longer
> > > to process the
> > > files being sent by the larger amount of files in multiple
> > > directories?
> > >
> > > I sure would like to have the answer to this. We are trying
> > > to complete an
> > > incremental backup an NT Server with about 3 million small objects
> > > (according
> > > to TSM) in many, many folders and it can't even get done in
> > > 12 hours. The
> > > actual amount of data transferred is only about 7GB per
> > > night. We have
> > > other
> > > backups that can complete 50GB in 5 hours but they are in one
> > > directory and
> > > the
> > > # of files is smaller.
> > >
> > > Thanks
> > >
> > >
> > >
> > >
> > >
> > > Network data transfer rate
> > > --------------------------
> > > The average rate at which the network transfers data between
> > > the TSM client and the TSM server, calculated by dividing the
> > > total number of bytes transferred by the time to transfer the
> > > data over the network. The time it takes for TSM to process
> > > objects is not included in the network transfer rate. Therefore,
> > > the network transfer rate is higher than the aggregate transfer
> > > rate.
> > > .
> > > Aggregate data transfer rate
> > > ----------------------------
> > > The average rate at which TSM and the network transfer data
> > > between the TSM client and the TSM server, calculated by
> > > dividing the total number of bytes transferred by the time
> > > that elapses from the beginning to the end of the process.
> > > Both TSM processing and network time are included in the
> > > aggregate transfer rate. Therefore, the aggregate transfer
> > > rate is lower than the network transfer rate.
> > >
>
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