Archiving in XProtect Enterprise, Professional and Basis+ Explained

Transcription

1 Archiving in XProtect Enterprise, Professional and Basis+ Explained Introduction The architecture of the Milestone XProtect Enterprise platform is uniquely designed to maximize the potential of your server(s). However, it can be quite difficult to understand exactly how to configure the software to meet your needs and avoid common issues like disk performance, or low disk space. This article describes exactly what happens during the archive process in XProtect Enterprise, Professional, and Basis+ which are all based on the same XProtect Enterprise platform. Database Capacity 40GB or 600,000 records The first thing you should know is that there is a maximum capacity for any given database. If you have archiving enabled though, this is usually not something you need to be worried about. Let me explain Each camera on your server has its own database. Even for multi-channel video encoders! You may have already noticed the folder structure of these databases. If you are recording do the default path, you might notice folders like C:\Program Files\Milestone\Milestone Surveillance\00408C01A12F_1 C:\Program Files\Milestone\Milestone Surveillance\00408C01A12F_2 C:\Program Files\Milestone\Milestone Surveillance\00408C01A12F_3 C:\Program Files\Milestone\Milestone Surveillance\00408C01A12F_4 C:\Program Files\Milestone\Milestone Surveillance\001A070036F6_1 C:\Program Files\Milestone\Milestone Surveillance\001A070036F6_1 C:\Program Files\Milestone\Milestone Surveillance\ DEF1A_1 You may have noticed that the first 4 folders in this example are the same, except that the last number increments from 1, 2, 3 and 4. The first 12 characters represent the MAC address, or serial number of the device. The number after the underscore is the channel number. For stand-alone single IP cameras, they will always be designated as <mac address>_1. For all video encoders, and some special IP cameras, each channel will have a number, and record to its own database. Each of these folders above contains the live database for that camera and has a maximum capacity - the first of 40GB or 600,000 records. What is a record? A record is defined as one MJPEG frame, or one second of MPEG4 video. The difference exists because Milestone software only counts key frames as records when recording in MPEG4, and the software will typically configure the cameras to send one key frame per second, with only a few exceptions. So, if you are recording in MJPEG at 10 frames per second, you are using 10 records per second. If you are recording at the same frame rate in MPEG4, you are only using 1 record per second. If you have audio enabled for any device, the audio channel will require 1 record per second. So in MPEG4 you will use 2 records per second with audio enabled, regardless of the frame rate. In MJPEG, you will use 1 more record per second than your recording frame rate, so 11 records per second when recording 10 frames per second with audio. You might be asking yourself What happens if I exceed the size (40GB) or record (600,000) limit?. That can be a tricky situation, but the answer is simple. If you exceed the capacity of

2 (Continued) Database Capacity 40GB or 600,000 records a database, the rule is first in, first out. If you are not archiving at all, or are not archiving often enough, then the first images recorded to the database get pushed out by new images. In this case, those images are not recoverable. This situation is unfortunate, but avoidable. When designing and planning a system, you should take into account the worst-case scenario. If you are recording on motion at 15 frames per second in MJPEG in a high activity environment, there s a good chance that you will record more than 600,000 records per day. In this case you would need to be able to archive more than once per day which means you are looking at the XProtect Enterprise product which can archive up to once per hour. As of the XProtect Enterprise 6.5 platform, there is an option in the settings for each camera within the Administrator called Archive automatically when database is full. With this feature enabled, the software will force an archive if the database becomes full unless there has been an archive for that camera made within the last hour. What happens during Archiving When it comes time for the software to archive, the following steps are performed. Software versions 6.0 and prior will do this as a batch job, where as of the 6.5 version it is done one camera at a time to minimize the effect of archiving on clients viewing video remotely. The first four steps occur in a matter of seconds 1. Camera and Image Server connections are closed (prior to 6.5) 2. Through a quick update to the file table, each live database is closed and moved to a temporary Archives directory at the same path as the database path if archiving to the same disk as the database is located. If you are archiving to a different drive than recording, then using the previous example, you would have an Archives folder in the following path C:\Program Files\Milestone\Milestone Surveillance\Archives 3. A new live database is created for each camera at the database path for each camera 4. Camera and Image Server connections are opened (prior to 6.5) and recording resumes Once recording has resumed, then the Archive Mover process begins if you are archiving to a different drive than you are recording to. The Archive Mover will, while the software is recording to the new set of live databases, transfer the archives from the temporary archive directory to the final location through a simple copy process, just like copying and pasting (or dragging and dropping) files from one drive to another. Or, for example, from a removable flash drive to your desktop. The Archive Mover will check available disk space on the archive drive before attempting to move each temporary archive. The threshold is the size of the temporary archive drive plus 1 gigabyte. If there is not enough disk space, then the software will delete the oldest archives for that camera until the available disk space is greater than the threshold. After the Archive Mover has successfully moved the temporary archive to the final archive location and verified that the entire database has been moved, it will then delete the database from the temporary archive directory and free up that disk space.

3 Troubleshooting There are several things that might go wrong in relation to your databases, archives, and the process of archiving. Depending on the situation your cameras could be offline for a very long time, you might have gaps in your recordings hours-long or you could even be missing entire days from some or all cameras. Fortunately all these problems are avoidable and normally a consequence of mis-configuration or poor planning. What you don t know CAN hurt you. Knowing what could go wrong will help you to avoid these situations in the future. Symptoms There are gaps in my recordings which seem to start at the scheduled archiving times Common Causes There are two common causes for gaps in recordings starting at the scheduled archiving time. 1. Your database(s) have reached their maximum capacity before the scheduled archive. Due to this, the first images recorded to the live database will be pushed out by newer video. If the system runs like this for several days, then from the client perspective it may simply appear that the cameras are consistently offline during this time. 2. Your cameras might actually be offline for an extended period of time during archiving. This is generally because you are recording to a low-end RAID 5 array which does not support the File Move command. This means that Windows must actually COPY the live database into the temporary archive directory instead of simply updating the file table with the new location of the folder. When you have several gigabytes of data in your live database folders, then it can take many minutes or even hours to complete that first step of the archive process. The only solution here is to either reconfigure the RAID array to standalone disks, RAID 0, RAID 1, or RAID 10, or to upgrade your HBA to a highend controller which supports a Hardware RAID 5. I m getting low disk space warnings in the Smart Client and I have gaps in recordings. What exactly is the software doing, and what can I do to fix this? There are two low disk space thresholds used to determine whether the software should take action against a low disk space event. 150 MB + 20MB/camera 10% disk space remaining These warnings are only displayed when the recording drive runs low on disk space, but not the archive drive. However, if the archive drive runs low on disk space, the event will be logged. When the recording drive is considered to be low on disk space, the

4 following actions will be taken: 1. If the archives are stored on the same logical drive, the oldest archives will be deleted. 2. If the archives are stored on a different logical drive, but there are temporary archives in-transit from the temporary directory to the final location, these will be deleted until outside of all low disk space thresholds 3. If there are no temporary archives, the software will force an archive as long as it has been more than 1 hour since the last archive 4. If the forced archive does not solve the problem (the archive does not leave the HDD fast enough), then it will be deleted from the temporary directory and the live database(s) will be automatically resized so that they can only hold a limited amount of recordings until the low disk space issues can be manually handled. Ultimately when a low disk space event occurs, it is an indication that the size of the recording drive(s) are not adequate for the amount of video you are recording. Following are the options for handling the event: 1. Reduce the amount of video being recorded by a. Reducing recording frame rates and/or resolution b. Archive more frequently (Enterprise is required) c. Add more disk space If archiving to the same drive as recording, set Delete databases in backup directory older than to a smaller number. This will store video for a shorter period of time, but avoid annoying messages and potential system down-time

5 My archives never leave the recording drive like they should, they remain in the temporary archive directory and eventually lead to low disk space warnings If your archives are not being transferred to the final archive directory, it could be one of two issues: 1. The Recording Server service does not have permission to read/write files to the archive directory 2. The Recording and/or Archiving drives are underperforming and the software cannot push archives off to the archive drive before the next scheduled archive while still managing to record new video. Resolution 1 Configure the Milestone Recording Server and Milestone Image Server services to run as an administrative user account with read/write access to the archive drive instead of the Local System account. 1. Go to Start -> Control Panel -> Administrative Tools -> Services 2. Locate and double-click the Milestone Recording Server service 3. Select the Log On tab 4. Choose This account instead of Local system account 5. Specify the username and password of an administrative user with full read/write access on the recording and archiving drives 6. Click Apply and OK 7. Now, back to the main Services window, Right-click on the service and select Restart to run the service with the new credentials 8. Repeat steps 2-7 for the Milestone Image Server service Resolution 2 If you are recording more data per second than the hard disks can process (non-sequential performance), then it is likely that archives will not be transferred from the temp directory to the final archive location before the next scheduled archive. Choosing to archive more frequently or reducing the amount of time you store video will not solve this problem since it is not a disk space issue, but an issue with disk performance. The only resolution here is to reduce the amount of data writing to the disk per second, or to spread the recording load across a larger quantity of hard disks. A single 3.5 HDD can typically handle approximately 6 MB/s of throughput or 48Mbps (megabits per second). A 2.5 mobile style of HDD can only support about 2.8 MB/s or 22.4Mbps. A rule of thumb for judging how many disks are required to keep up with a given number of cameras is to determine the total bandwidth coming in from all cameras over the network in megabits per second, and divide by 48 (or 22.4 for 2.5 drives). This number when rounded up is the approximate number of physical disks required to process that amount of data using standalone drives, or a RAID 0. Double the disks if using RAID 1 or RAID 1+0 for redundancy.