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Backup Times RRS feed

  • Question

  • When you install the connector software on your machines and ask that whs wakes them up from sleep or hibernation the default time when the connector software pops up is set to 'wake my pc up 12a-6a'

    If then you change the backup time in the whs console to 12a-3a could this explain why my laptop no longer is woken up and backed up?

    I'm running the lightsout add-in and have not installed the lightsout client install on this machine although I can't see whay that would inpact?

    Another question, if I have say 3-5 pcs on my network all to be backed up overnight by whs and I reduce the backup window time back from 6 hours to 3 hours will whs try to start the pc backups sooner to fit into the window ?

    I look at the start times of my backups and it does not make any sence as to when they are run

    1 pc at 12.17am for 2 mins 31 secs, the next machine not until 1.17am for 5 mins 16 secs

    I have installed and uninstalled the whs connector software several times on each machine, could this be adding problems to each machines registry?
    Are there any steps I could take if this is a problem to clean each machines reg settings up and then do a fresh connector install?

    Just trying to suss out how several things work with whs

    Any info appreciated.

    Thanks

    Paul
    Dunedin, New Zealand
    Wednesday, October 22, 2008 3:51 AM

Answers

  • Changes to the backup window will filter down to the clients the next time they run a backup, if not sooner.

    Regarding the times you quote, you did see that I said the clients randomly choose a time to start their backups, right?

    The length of time a backup takes delends on the amount of data to be transferred. If the client PC has been backed up previously, and little has changed, then it will normally only take a few minutes to back that client up even over a 100 Mbit link (or even wireless). If it's the first backup for a particular client, it will take much longer, possibly an hour or more. If it's the first backup ever for the server (this also applies after you reset the backup database), it will have to transfer every byte on the client PC to the server, so it will take a very long time. A client PC with a large amount of media could easily take multiple hours.

    There's no need to flag any particular backup of a PC as "a key one to keep". When Windows Home Server does it's cleanup (sunday mornings) it reorganizes the backup database, removing backups that don't meet the retention policy guidelines. But there will always be a full backup of every client in the database.

    I'm not on the WHS team, I just post a lot. :)
    • Marked as answer by Paul151 Friday, October 24, 2008 7:03 AM
    Thursday, October 23, 2008 4:46 PM
    Moderator

All replies

  • Paul,

    Firstly, if you have installed part of 'LightsOut', then you should do the remainder, just so the Clients can wake the server when necessary.

    The Backup period is a matter of negotiation between the Client software, and the server. The time window is set by the user, which is then communicated to each Client. each Client will then wake at the start of this window and call the server to negotiate a backup time. This particular time window however, isn't a sequence of times, ( computer A, 00:00 to 00:15, computer B 00:15 to 00:30) etc., because the server has no way of knowing how much data there may be to backup on computer A before moving on to computer B. Also, the server has other scheduled jobs to do itself during this window, disk checking, file integrity, space calculations etc.

    What you are seeing is the way that WHS handles this 'problem', it will leave more than enough time between computer A, (which was probably the first one to contact it after waking), before moving on to computer B.

    There is nothing you can do to change this, as this version of WHS just cannot predict in advance how much time to allocate to each Client for it's backup time. Maybe in future versions, there could be some 'intelligence' applied, ie, the one with the most data to backup will be No.1 and then so on down the line.

    What will happen if you just keep reducing the backup window, is that some Clients will not be backed up at all, as their negotiated time could be outside this window.

    HTH,

    Colin






    If anyone answers your query successfully, please mark it as 'Helpful', to guide other users.
    Wednesday, October 22, 2008 1:38 PM
    Moderator
  • Colin Hodgson said:

    The Backup period is a matter of negotiation between the Client software, and the server. The time window is set by the user, which is then communicated to each Client. each Client will then wake at the start of this window and call the server to negotiate a backup time. This particular time window however, isn't a sequence of times, ( computer A, 00:00 to 00:15, computer B 00:15 to 00:30) etc., because the server has no way of knowing how much data there may be to backup on computer A before moving on to computer B. Also, the server has other scheduled jobs to do itself during this window, disk checking, file integrity, space calculations etc.

    Not quite. The client is informed by the server of the backup window during backup configuration and when the client contacts the server to begin a backup. (Maybe other times too, but those are times I'm pretty confident of.) The client then randomly chooses a backup time within the backup window for it's next backup. (With an apparent preference for an early start time; my PCs normally back up between midnight and 2:00 AM, though I did once see one still running at a couple of minutes after 6:00.) This is an important point, because of this scenario:
    • Backup window on the server is configured for e.g. noon to 6:00 PM.
    • Client backup is configured.
    • Backup window on the server is configured for e.g. midnight to 6:00 AM, before the client fires off a backup.
    In this scenario, the client will perform one backup between noon and 6:00 PM, and another 6 to 18 hours later. (I've tested this scenario, BTW, though not for nearly a year now.) It performs the backup between noon and 6:00 PM because that's what it was originally configured to do, and it will perform this backup even though the backup window has changed. The client drives the backup; as long as the server is set for the client to back up regularly you could in theory have the client back up every 15 minutes (there is an undocumented and unsupported way to force a normal backup at an arbitrary time).

    If one client tries to start a backup while another is currently backing up, it will queue up and wait it's turn.

    I'm not on the WHS team, I just post a lot. :)
    Wednesday, October 22, 2008 4:11 PM
    Moderator
  • Colin Hodgson said:

    The Backup period is a matter of negotiation between the Client software, and the server. The time window is set by the user, which is then communicated to each Client. each Client will then wake at the start of this window and call the server to negotiate a backup time.

    Ken Warren said:
    Not quite. The client is informed by the server of the backup window during backup configuration and when the client contacts the server to begin a backup. (Maybe other times too, but those are times I'm pretty confident of.) The client then randomly chooses a backup time within the backup window for it's next backup. (With an apparent preference for an early start time; my PCs normally back up between midnight and 2:00 AM, though I did once see one still running at a couple of minutes after 6:00.) This is an important point, because of this scenario:
    • Backup window on the server is configured for e.g. noon to 6:00 PM.
    • Client backup is configured.
    • Backup window on the server is configured for e.g. midnight to 6:00 AM, before the client fires off a backup.
    In this scenario, the client will perform one backup between noon and 6:00 PM, and another 6 to 18 hours later. (I've tested this scenario, BTW, though not for nearly a year now.) It performs the backup between noon and 6:00 PM because that's what it was originally configured to do, and it will perform this backup even though the backup window has changed. The client drives the backup; as long as the server is set for the client to back up regularly you could in theory have the client back up every 15 minutes (there is an undocumented and unsupported way to force a normal backup at an arbitrary time).

    If one client tries to start a backup while another is currently backing up, it will queue up and wait it's turn.

    I'm not on the WHS team, I just post a lot. :)



    Hi Colin & Ken,

    Firstly thanks for the replys and your info - appreciated.

    Re my laptop - I did plug it into a wired connection to my network last night and lo and behold it did back up for the first time in many days so I point my lack of backup problem at the wireless card / driver / config

    Ken - so by changing the backup window on the server this change will (if I understand you correctly) filter through to the client within 1-2 days and then from there on the client will play by the new rules? Can you confirm this please as if this is the case it would ease my mind about having to uninstall / re-install the connector on each pc when I make a change to the server window.

    Some further info..

    I had three pc's on the lan last night all with clients installed with the server set backup window of 12a-6a.

    I had also changed the window on the server to 12a-3a as I figure 3 hours was enough time to run these backups on all the 3 pcs. After all they are only picking up the incremental changes are they not?? so when you look at the info below you will see the longest times for last nights run was just over 5 mins.

    All backed up but the times were

    PC1 - start 12.16a dur 3 mins 20 secs
    PC2 - start 2.13a dur 5 mins 47 secs
    PC3 - start 2.19a dur 1 min 5 secs

    I still find it strange that the server can sit for so long idle between 12.19a and then tackle 2 pcs almost one after another from 2.13a

    Do you know if the backups are more 'comprehensive' ie: take longer when a full month or week comes along? I'm just wondering if the whs tackles these weekly, monthly backups with a little more gusto or are they all incremental after the first initial pc backup?

    If the answer to the above question is yes I guess it makes any first backup of a pc on whs a key one to keep.

    Thanks guys,

    Paul
    Dunedin, New Zealand

    Thursday, October 23, 2008 7:44 AM
  • Hi Paul,
    the very first backup you perform will usually be the longest.
    Subsequential PCs will already take less time (since the clusters for duplicate files do not need to be transferred,  and subsequent backups of the same PC do also not take that long, unless a lot of data or some big files have been changed.
    From time to time such changes may not even be real changes like adding files are - lets assume some scenarios: a virus scanner touches each file more than it should and leaves so a changed version, you defragmented the disk (according to some experiences of other people this increases the amount of transfered data and therefore the length of the backup time) and so on.

    Regarding the startup difference:
    The clock on all machines runs identical?
    Could it be, that a former backup of PC 1 took longer and the client does not start it's next backup earlier because of the delayed last start? (only speculating here)

    Clean up happens each week on Sunday during the backup window. But this will only remove data from older backups, which does not exist in subsequent backups.

    Best greetings from Germany
    Olaf
    Thursday, October 23, 2008 10:48 AM
    Moderator
  • Paul,

    There isn't continuous communication between the server and clients, so once they 'know' the window time, it's up to the client to start the backup at a time in that window.

    I guess the ideal would be that the server communicates continuously with all the clients, and start No.2 as soon as No.1 has finished. However, that isn't the case, which is why you see the gaps. I guess this could be because of the unknown amount of data that could be due to be backed up.

    In essence, they are all incremental, the server then keeps the backups as you decide in the schedule.
    Because of the single instance file storage, the ideal would be that the first ever backup, is done on the Client which has the most data stored on it, as there will then be less for subsequent client backup data to be transferred.
    Because of the way the database is, if for example, you pick 'last nights' backup to be the restore, then the server doesn't just restore that incremental backup, it knows that there are other files within the database that belong to that particular client, all the way back to the beginning of the stored backups, so will restore a complete set of files.
    Don't forget that this is initially designed as a disaster recovery mechanism, so isn't a method of 'rolling back' a client system to an intermediate state. To do that, it becomes a manual operation, by opening a backup, and copying files back to the client manually.

    Colin






    If anyone answers your query successfully, please mark it as 'Helpful', to guide other users.
    Thursday, October 23, 2008 11:00 AM
    Moderator
  • Changes to the backup window will filter down to the clients the next time they run a backup, if not sooner.

    Regarding the times you quote, you did see that I said the clients randomly choose a time to start their backups, right?

    The length of time a backup takes delends on the amount of data to be transferred. If the client PC has been backed up previously, and little has changed, then it will normally only take a few minutes to back that client up even over a 100 Mbit link (or even wireless). If it's the first backup for a particular client, it will take much longer, possibly an hour or more. If it's the first backup ever for the server (this also applies after you reset the backup database), it will have to transfer every byte on the client PC to the server, so it will take a very long time. A client PC with a large amount of media could easily take multiple hours.

    There's no need to flag any particular backup of a PC as "a key one to keep". When Windows Home Server does it's cleanup (sunday mornings) it reorganizes the backup database, removing backups that don't meet the retention policy guidelines. But there will always be a full backup of every client in the database.

    I'm not on the WHS team, I just post a lot. :)
    • Marked as answer by Paul151 Friday, October 24, 2008 7:03 AM
    Thursday, October 23, 2008 4:46 PM
    Moderator
  • All good, thanks guys for the helpful info I will continue to watch this os and learn along the way with the rest of the whs team :-)

    Now I just need to get my laptop / wireless card sorted.. although whs backed up my wired laptop 2 nights ago for some strange reason it did not back it up this morning.
    Friday, October 24, 2008 7:05 AM